CN104639846A - Image switching system, image switching device and image switching method - Google Patents

Abstract

The invention discloses an image switching system. The image switching system includes at least one display device, multiple image sources and a switch. Each image source provides an image. The switch is coupled to at least one display device and multiple image sources respectively. The switch includes a storage module, an image receiving module, a scaling module and an image timing control module. The image receiving module receives a first image among multiple images. The scaling module performs a first scaling process on the first image to form a first processed image. The image timing control module outputs the first processed image to the display device. During the period when the first image is switched to the second image, the switch stores the first processed image output to the display device in the storage module according to the trigger mechanism.

Description

Image switching system, image switching device and image switching method

technical field

The invention relates to image transmission, in particular to an image switching system, an image switching device and an image switching method.

Background technique

In a traditional image switching system, a switcher is respectively coupled to a plurality of audio-visual or image sources and at least one display device. When the switcher performs switching of input images from multiple audio-visual or image sources, if the switcher only amplifies the input image with a lower resolution provided by the audio-visual or image source that needs to be enlarged to a higher-resolution input image output image, or just reduce the input image with higher resolution provided by the audio-visual or image source that needs to be reduced to an output image with lower resolution, then when the display device displays these output images, it can indeed It presents a good display effect with traceless and noise-free picture output.

However, once the switcher receives the switching signal, the source of the input image is switched from the first input image with a lower resolution (as shown in FIG. 1A ) provided by the audio-visual or image source that needs to be enlarged to the audio-visual that needs to be reduced. Or the second input image with higher resolution provided by the image source (as shown in Figure 1B), during the instant switching process, the output image displayed on the display device will appear as noise as shown in Figure 1C The dirty frame causes troubles for users when viewing, and needs to be overcome urgently.

Contents of the invention

Therefore, the present invention proposes an image switching system, an image switching device, and an image switching method to solve the above-mentioned problems encountered in the prior art. The present invention stores the first processed image output to the display device according to a trigger mechanism during switching from a first image to a second image, and outputs the stored first processed image to the output device during the switching period. The aforesaid period of switching from the first image to the second image may broadly include the time point at which the switching signal triggering the generation of the switching image occurs. In one embodiment, the trigger mechanism may be a switching signal for switching the first image to the second image; in another embodiment, the trigger mechanism may be changed from receiving the first image to receiving the second image When there are two images, the trigger mechanism is determined by determining that the received second image is an unstable image.

A specific embodiment according to the present invention is an image switching system. In this embodiment, the image switching system includes at least one display device, a plurality of image sources and a switcher. Each image source provides an image. The switcher is respectively coupled to at least one display device and a plurality of image sources. The switcher includes a storage module, an image receiving module, a scaling module and an image timing control module. The image receiving module receives the first image among the plurality of images. The scaling module performs a first scaling process on the first image to form a first processed image. The image timing control module outputs the first processed image to the display device. During the period of switching from the first image to the second image, the switcher stores the first processed image output to the display device in the storage module according to the trigger mechanism.

In one embodiment, the trigger mechanism is a switching signal. The image receiving module receives the second image according to the switching signal, and the scaling module performs a second scaling process on the second image. When the scaling module has not completed the second scaling process, the image timing control module outputs the first processed image stored in the storage module to the display device; when the scaling module completes the second scaling process to form a second processed image, the image timing The control module outputs the second processed image to the display device.

In one embodiment, the trigger mechanism is a switching signal. The image receiving module receives the second image according to the switching signal, and the scaling module performs a second scaling process on the second image. The image timing control module outputs the stored first processed image to the display device at least once within a specific time period, and after outputting the stored first processed image at least once, converts the second image to the second image formed by the second scaling process. 2. The processed image is output to a display device.

In one embodiment, the first scaling process is the process of reducing the image resolution and the second scaling process is the process of enlarging the image resolution, or the first scaling process is the process of enlarging the image resolution and the second scaling process is zooming out Image resolution processing.

In one embodiment, during the resolution processing of the enlarged image, the first image or the second image is first stored in the storage module, and then processed by the scaling module to perform the resolution processing of the enlarged image, and then the processed first processed image or The second processed image is output to the display device.

In one embodiment, when processing the reduced image resolution, the first image or the second image is first input to the scaling module for reduced image resolution processing, and then the processed first processed image or the second processed image The image is stored in the storage module, and then output to the display device by the storage module.

In one embodiment, the triggering mechanism is that when the image receiving module changes from receiving the first image to receiving the second image, if the image receiving module determines that the second image it receives is not stable, the image timing control module will read the information stored in the storage module. The stored first processed image is output to a display device.

In one embodiment, if the image receiving module determines that the received second image is stable, it outputs the second image to the scaling module to perform a second scaling process on the second image to form a second processed image. The image timing control module reads the second processed image stored in the storage module and outputs it to the display device.

In one embodiment, if the image receiving module determines that the second image it receives is stable, the second image is stored in the storage module, and the scaling module reads the second image stored in the storage module and performs a second scaling process on the second image to A second processed image is formed, and the image timing control module outputs the second processed image to the display device.

In one embodiment, the first scaling process is the process of reducing the image resolution and the second scaling process is the process of enlarging the image resolution; or the first scaling process is the process of enlarging the image resolution and the second scaling process is zooming out Image resolution processing.

In one embodiment, during the resolution processing of the enlarged image, the first image or the second image is first stored in the storage module, and then processed by the scaling module to perform the resolution processing of the enlarged image, and then the processed first processed image or The second processed image is output to the display device.

In one embodiment, when processing the reduced image resolution, the first image or the second image is first input to the scaling module for reduced image resolution processing, and then the processed first processed image or the second processed image The image is stored in the storage module, and then output to the display device by the storage module.

In one embodiment, the trigger mechanism is that when the image receiving module changes from receiving the first image to receiving the second image, if the image receiving module determines that the second image it receives is not stable, the image timing control module reads the first image from the storage module. A processed image is output to a display device.

In one embodiment, if the image receiving module determines that the received second image is stable, the image receiving module outputs the second image to the scaling module to perform a second scaling process on the second image to form a second processed image, and the storage module The second processed image is stored, and the image timing control module reads the second processed image and outputs it to the display device.

In one embodiment, if the image receiving module determines that the second image it receives is stable, the second image is stored in the storage module, and the scaling module reads the second image stored in the storage module and performs a second scaling process on the second image to A second processed image is formed, and the image timing control module outputs the second processed image to the display device.

In one embodiment, the first processed image stored by the storage module is an image displayed by the display device.

Compared with the prior art, the image switching system, image switching device, and image switching method according to the present invention determine the timing of restoring normal and stable images through a trigger mechanism (such as switching signals or judging unstable images), and when being switched During the period when the new image provided by the audio-visual or image source has not yet reached the normal and stable state, provide the restored normal and stable image to the display device for display until it is determined that the new image provided by the switched audio-visual or image source has reached the normal and stable state When a new image is provided to the display device for display, the image switching system, image switching device and image switching method of the present invention can effectively avoid the problem that the traditional display device displays a dirty frame during the instantaneous switching process , in order to achieve the fast cut effect of seamless and noise-free picture output.

The advantages and spirit of the present invention can be further understood through the following detailed description of the invention and the accompanying drawings.

Description of drawings

FIG. 1A shows a first input image with a lower resolution.

FIG. 1B shows a second input image with a higher resolution.

FIG. 1C is a schematic diagram of an output image displayed by a display device in the prior art with noise.

FIG. 2 is a schematic diagram of an image switching system according to an embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating an initialization procedure between an audio-visual or image output device and an audio-visual or image source.

FIG. 4 is a schematic diagram of the internal structure of the switcher in the video switching system.

Figures 5 and 6 respectively illustrate the enlargement of an input image with a lower resolution to an output image with a certain fixed resolution and the reduction of an input image with a higher resolution to a certain fixed resolution through the operation of the switcher, respectively. Schematic diagram of the output image in degrees.

FIG. 7 is a flow chart of an image switching method according to another embodiment of the present invention.

8A to 8C are schematic diagrams illustrating the operation of the image switching method in the image switching system.

FIG. 9 is a flowchart of another embodiment of the image switching method of the present invention.

FIG. 10 shows another embodiment of the switcher in the video switching system of the present invention.

【Symbol Description】

S10～S30: process steps

2: Image switching system

20: Switcher

S1～S4: audio-visual or video source

D1～D4: Audio-visual or image output device

I0～I3: the first interface

I4～I7: Second interface

SW: switch signal

200: image receiving module

201: Zoom module

202: storage module

203: Image timing control module

204: Image switching module

HPD: Hot Plug Detection

EDID: Extended Display Identification Data

HDCP: High Definition Content Protection

V1: Input image with resolution 800x600

V2, V4, V2’: Output image with fixed resolution 1280x720

V3: Input image with resolution 1920x1080

NS: Unstable picture

Detailed ways

A preferred embodiment of the present invention is an image switching system. In this embodiment, the image switching system includes a switcher, a plurality of audio-visual or image sources, and at least one audio-visual or image output device. Please refer to FIG. 2 , which is a schematic diagram of the image switching system in this embodiment.

As shown in FIG. 2 , the image switching system 2 includes a switcher 20 , audio-visual or image sources S1 - S4 , and audio-visual or image output devices D1 - D4 . It should be noted that the number of audio-visual or image sources and audio-visual or image output devices included in the image switching system 2 is not limited to four in this example. Actually, the number of audio-visual or image sources can be two or more, and the number of audio-video or image output devices can be one or more.

In practical applications, the switch 20 may be an audiovisual switch or a keyboard, video and mouse switch (KVM switch). In this embodiment, the switcher 20 is an array type audio-visual switcher, but it is not limited thereto.

As shown in FIG. 2 , the first side and the second side of the switch 20 respectively have a plurality of first interfaces I0 - I3 and a plurality of second interfaces I4 - I7 . Wherein, the first interfaces I0-I3 are used to couple the audio-visual or image sources S1-S4; the second interfaces I4-I7 are used to couple the audio-visual or image output devices D1-D4.

Actually, the first interfaces I0-I3 may be Video Graphics Array (VGA) interface, Digital Visual Interface (DVI), Display Port (Display Port) interface or High-resolution multimedia interface (High- Definition Multimedia Interface, HDMI) and other input interfaces, but not limited thereto. The audio-visual or image sources S1-S4 can be computers or audio-visual players (such as DVD players or Blu-ray DVD players), but are not limited thereto. The second interfaces I4-I7 can be video graphics array (VGA) interface, digital video interface (DVI), display port (DisplayPort) interface or high-resolution multimedia interface (HDMI) output interface, but not limited thereto. The audio-visual or image output devices D1-D4 can be various display devices, such as liquid crystal display devices or plasma display devices, but not limited thereto. The audio-visual or image sources S1-S4 can provide input images with at least one first resolution, and the audio-visual or image output devices D1-D4 can support the display of output images with at least one second resolution.

In this embodiment, the function of the switcher 20 is to select and switch to different audio-visual or image sources S1-S4 according to the actual needs of users and output the input audio-visual or image signals to one or more specific audio-visual or image sources. Output device D1 ~ D4. For example, the user can output the audio-visual or image signal input by a single audio-visual or image source S1 to a single audio-visual or image output device D1 or a plurality of audio-visual or image output devices D2-D3 by switching the switcher 20. show. In addition, the user can also output a plurality of audio-visual or image signals respectively input by the plurality of audio-visual or image sources S1-S4 to different display devices through the switch 20, for example, the first audio-visual or image source can be output at the same time. Output the audio-visual or image signal of S1 to the second audio-visual or image output device D2, output the audio-visual or image signal of the second audio-visual or image source S2 to the third audio-visual or image output device D3, and output the audio-visual or image signal of the third audio-visual or image source S3 The audio-visual or image signal is output to the first audio-visual or image output device D1 and the audio-visual or image signal of the fourth audio-visual or image source S4 is output to the fourth audio-visual or image output device D4, but not limited thereto, the user can according to Different switching controls are performed arbitrarily according to actual requirements.

Please refer to FIG. 3 . FIG. 3 is a schematic diagram of an initialization procedure between an audio-visual or image output device and an audio-visual or image source. As shown in FIG. 3 , in one embodiment, when the switch switches and connects any one of these audio-visual or image output devices D1 to D4 (taking the first audio-visual or image output device D1 as an example) to these audio-visual or image output devices When any one of the video sources S1-S4 (take the first video or video source S1 as an example), if the first video or video source S1 is an HDMI interface, the first video or video output device D1 and the first video or video source The initial communication will be established between S1.

In this embodiment, the above-mentioned initialization communication process includes mutual transmission of Hot-Plug-Detect (HPD), extended display identification data (Extended display identification data, EDID) and high-resolution content protection (High Definition Content Protection, HDCP) authorization code and other two-way communication. Therefore, in the process of video switching by the switcher 20, for example, for the same first audiovisual or video output device D1, when the switcher 20 switches to different audiovisual or video sources S1-S4, only the audiovisual or video Any source changes require an initialization procedure. Generally speaking, it takes about 3 to 10 seconds to establish the initial communication. Since the first audio-visual or image source S1 cannot transmit images to the first audio-visual or image output device D1 during the initial communication establishment process, the first audio-visual or image output device D1 cannot output images during the initialization process.

In order to avoid the above situation, in one embodiment, the image switching system 2 can output an output with a fixed resolution by controlling the switcher 20 to scale the input images with different resolutions from different audio-visual or image sources S1-S4 Images are given to these audio-visual or image output devices D1-D4 to avoid the problem of re-initialization due to switching between audio-visual or image sources S1-S4 and audio-visual or image output devices D1-D4, so it can shorten the time due to audio-visual or image sources. The time during which audio-visual or video output devices D1-D4 cannot output pictures due to switching between S1-S4. It should be noted that the fixed resolution of the output image of the switcher 20 can be determined according to actual needs, and there is no certain limitation.

In the method for shortening the time when audiovisual or image output devices D1～D4 cannot produce pictures, what must be solved is how to provide different audiovisual or image sources S1～S4 when switching audiovisual or image sources S1～S4. The resolution images are effectively scaled to output images with a fixed resolution to the audio-visual or image output devices D1 - D4 .

Please refer to FIG. 4 , which shows a schematic diagram of the internal structure of the switcher 20 in the video switching system 2 . In this embodiment, the switcher 20 at least includes an image receiving module 200 , a scaling module 201 , a storage module 202 , an image timing control module 203 and an image switching module 204 . Wherein, the image switching module 204 is respectively coupled to the audio-visual or image sources S1-S4 through the first interfaces I0-I3; the image switching module 204 is coupled to the image receiving module 200; the image timing control module 203 is coupled to the Audio-visual or image output devices D1-D4; the image receiving module 200 is selectively coupled to the scaling module 201 and the storage module 202; the scaling module 201 is selectively coupled to the storage module 202 and the image timing control module 203; the storage module 202 is selectively It is coupled to the scaling module 201 and the image timing control module 203 . It should be noted that although FIG. 4 only shows each second interface I4, for other second interfaces I5-I7 as shown in FIG. The structure is outlined here. That is, the image receiving module 200 is respectively coupled with four sets of scaling modules 201, storage modules 202, and video timing control modules 203 respectively corresponding to the second interfaces I4-I7. Hereinafter, only the scaling modules corresponding to the second interface I4 are used. 201, the storage module 202, and the image timing control module 203 for switching description.

In this embodiment, the image switching module 204 is used to determine that the input image of one or more of the audio/video or image sources S1-S4 can be transmitted to the image receiving module 200 according to a switching signal SW. The image timing control module 203 is used for controlling to transmit the output image to the output device D4 coupled to the second interface I4.

Please refer to FIG. 5 and FIG. 6. FIG. 5 and FIG. 6 respectively show that the input image with a lower resolution is amplified to an output image with a certain fixed resolution and the input image with a higher resolution is amplified through the operation of the switcher. Schematic diagram of downscaling an image to an output image with a fixed resolution. Assume that the preset fixed resolution of the switcher 20 in this embodiment is 1280×720, which is the resolution that can be displayed by the audio-visual or video output devices D1-D4.

As shown in FIG. 5 , assuming that the first audio-visual or image source S1 provides an input image V1 with a resolution of 800x600, since the resolution 800x600 of the input image V1 is smaller than the fixed resolution 1280x720 preset by the switcher 20, it means switching The device 20 first upscales the input image V1 with a lower resolution of 800x600 into an output image V2 with a fixed resolution of 1280x720, and then transmits the output image V2 to a specific audio-visual or image output device D1. The flow of the above enlargement procedure is as follows: the image receiving module 200 stores the input image V1 with a resolution of 800x600 in the storage module 202, and then transmits it to the scaling module 201 for enlargement processing, and the enlarged output image V2 has a resolution of 1280x720 Spend. Then, the scaling module 201 transmits the output image V2 with a fixed resolution of 1280x720 to the image timing control module 203, and then the image timing control module 203 outputs the output image V2 with a fixed resolution of 1280x720 to the audio-visual or image output device D1 for playback .

As shown in FIG. 6 , suppose that the first audio-visual or image source S1 provides an input image V3 with a resolution of 1920x1080. The device 20 first downscales the input image V3 with a higher resolution of 1920x1080 into an output image V4 with a fixed resolution of 1280x720, and then transmits the output image V4 to a specific audio-visual or image output device D1. The process of the reduction procedure is as follows: the image receiving module 200 transmits the input image V3 with a resolution of 1920×1080 to the scaling module 201 for reduction processing to an output image V4 with a fixed resolution of 1280×720, and then stores it in the storage module 202 . Afterwards, the video timing control module 203 outputs the output video V4 with a fixed resolution of 1280×720 to the audio-visual or video output device D1 for playback.

In the zoom-in or zoom-out processing procedures of the above-mentioned FIG. 5 and FIG. 6, since the input image V1 with a resolution of 800x600 and the output image V4 with a resolution of 1280x720 stored in the storage module 202 are relatively small in resolution and data volume image, so the memory space of the storage module 202 can be saved. For example, in the enlarging procedure shown in FIG. 5 , the input image V1 with a lower resolution of 800×600 is stored in the storage module 202 first, and then the enlarging process is performed; In the processing program, the input image V3 with a higher resolution of 1920x1080 is first reduced by the scaling module 201 into an output image V4 with a resolution of 1280x720, and then the output image V4 with a lower resolution of 1280x720 is stored in the storage module 202 Therefore, the data stored in the guaranteed output image V4 is the image with the smallest resolution and data volume.

In this embodiment, only one zoom module 201 is required for the switcher 20 to perform zoom-in and zoom-out processing, and it can change the direction of receiving data according to the requirements of zoom-in or zoom-out processing, so there is no need to additionally set up other zoom modules, In order to save the installation space and the number of scaling modules and storage modules, thereby reducing the cost. For example, in the enlargement processing program, as shown in FIG. 4 and FIG. 5 , the path of image signal transmission is: image receiving module 200 => storage module 202 => scaling module 201 => image timing control module 203, to The enlarged video signal is first stored in the memory module 202, and then the zoom module 201 performs the zoom processing; in the program of zooming out, as shown in Figure 4 and Figure 6, the path of video signal transmission is: image receiving module 200= >Scaling module 201 => storage module 202 => image timing control module 203 , the image signal to be reduced is first reduced by the scaling module 201 , and then the reduced image signal is stored in the storage module 202 . Therefore, although the switcher 20 only includes a single scaling module 201, the image can be reduced or enlarged by switching.

Next, it will be discussed why the display device in the traditional image switching system has a dirty frame as shown in FIG. 1C . Please refer to FIG. 4 to FIG. 6 to illustrate the reasons for the above-mentioned noise screen. It should be noted that although the audio-visual or image output device D1 displays images with a resolution of 1280x720 in this embodiment, it does not mean that the audio-visual or image output device D1 only has the display capability of this resolution, and the user can still display images according to actual needs. Adjust to the desired resolution.

Assuming that the input image V1 with the first resolution 800x600 to be amplified is originally provided by the first audio-visual or image source S1 to be processed by the switcher 20 and then output to the audio-visual or image output device D1 for playback. When the image source S1 is switched to the second audio-visual or image source S2, what the second audio-visual or image source S2 provides is an input image V3 with a second resolution of 1920 x 1080 that needs to be reduced. At this moment of switching, due to the previous The time point belongs to the image enlargement processing program, so the image stored in the storage module 202 is the input image V1 with the first resolution 800x600 directly provided by the first audio-visual or image source S1; and at the first time point after switching, Since the source of the image signal received by the scaling module 201 will be switched from the storage module 202 to the image receiving module 200 for shrinking processing, and at the same time, the source of the image signal obtained by the image timing control module 203 will also be switched from the scaling module 201 to the image receiving module 200. From the storage module 202, the image signal obtained from the storage module 202 is output to the audio-visual or image output device D1, because the image stored in the storage module 202 is directly provided by the first audio-visual or image source S1 with a first resolution of 800x600 The input image V1, therefore, what the image timing control module 203 obtains from the storage module 202 is the input image V1 with a first resolution of 800x600 instead of the output image V4 with a fixed resolution of 1280x720, thus causing the image timing control module 203 to transmit to The output image of the audio-visual or image output device D1 is not the output image V4 with a fixed resolution of 1280x720, but the input image V1 with a lower resolution of 800x600, so that when the audio-visual or image output device D1 plays according to the preset fixed resolution of 1280x720 , the display screen will appear a noise screen as shown in FIG. 1C.

In order to solve the above problems, the present invention further provides an image switching method. As shown in FIG. 7 , in step S10 , the method selects a first image with a first resolution (800×600 in this example). Actually, the first image can be selected from the first audio-visual or image source S1 with HDMI interface, but not limited thereto.

Next, in step S12, the method performs a first scaling process on the first image to form a first processed image, and outputs the first processed image to the first audio-visual or image output device D1. In fact, the first scaling process may be to enlarge the first image with the first resolution of 800x600 to a preset fixed resolution (in this example, 1280x720, which is the resolution supported by the first audio-visual or image output device D1 ). As shown in FIG. 5 , the first image from the first audio-visual or image source S1 is enlarged into a first processed image with a resolution of 1280×720, and then played by the first audio-visual or image output device D1.

Then, in step S14 and step S16, the method receives a switch signal, and uses the switch signal as a trigger mechanism, that is, stores the first processed image according to the switch signal and switches the first audio-visual or image source S1 to the second Two audio-visual or image sources S2. That is to say, the image input to the switcher will change from the original input image V1 provided by the first audio-visual or image source S1 to the input image V3 provided by the second audio-visual or image source S2. In fact, the switching signal can be transmitted through wireless or wired, or the user directly presses the button of the switcher corresponding to a specific audio-visual or image source, so that the switcher switches from the original first audio-visual or image source S1 to the second audio-visual or video source. Image source S2. In this example, the input image V3 provided by the second audio-visual or image source S2 has a second resolution of 1920×1080.

Next, the execution process of step S16 will be described in detail. Please refer to FIG. 8A , in step S16, when the switcher 20 receives a switching signal for switching audio-visual or video source, the switcher 20 will firstly transfer the output video currently being transmitted from the scaling module 201 to the video timing control module 203 V2 is synchronously stored in the storage module 202 . After the switcher 20 completes the switching of the video or video source, the video source received by the video receiving module 200 will change from the first video or video source S1 shown in FIG. 8A to the second video or video source S1 shown in FIG. 8B. Image source S2.

Referring back to FIG. 7 , in step S18 , the method performs a second scaling process on the second image V3 from the second audio-visual or image source S2 to generate a second processed image with a fixed resolution. As shown in FIG. 8B , since the resolution of the input image V3 of 1920x1080 is greater than the fixed resolution of 1280x720 preset by the switcher 20, the input terminal of the scaling module 201 will be switched to be coupled to the image receiving module 200 to receive the input image V3. , and downscale the input image V3 to an output image V4 with a fixed resolution of 1280x720.

As shown in FIG. 7 , during the shrinking process, the method will perform steps S20 - S24 . In step S20 , the switcher continues to judge whether the operation of reducing the input image V3 to the output image V4 is completed. If not, it means that the image is still shrinking and has not been completed, then the method proceeds to step S24, and the output image V2 stored in step S16 is output to the first audio-visual or image output device D1 for playback by the first audio-visual or image output device D1 Output image V2; if yes, it means that the image has been shrunk, then the method proceeds to step S22, outputting the shrunk output image V4 to the first audio-visual or image output device D1 for playback and output by the first audio-visual or image output device D1 Image V4. Since the pre-stored image V2 is first output to the output device D1 before the scaling process of the image V3 is completed, this method can effectively overcome the problem of shrinking the input image V3 into the output image V4 in the prior art. The problem that the display device will play a noisy screen when it is completed.

Next, the above steps S20 to S24 will be described in detail with reference to FIG. 8B and FIG. 8C . As shown in FIG. 8B , before shrinking the input image V3 into an output image V4 with a fixed resolution, the image information obtained by the image timing control module 203 from the storage module 202 is stored in the first video or video in FIG. 8A . The image output device D1 outputs the image V2' with the resolution, and outputs it to the display device D1. Until, as shown in FIG. 8C , the scaling module 201 reduces the input image V3 with the second resolution 1920×1080 provided by the second audio-visual or image source S2 into an output image V4 that can be completely played on the first audio-visual or image output device D1 After that, the image timing control module 203 will obtain the output image V4 corresponding to the resolution of 1280×720 of the first audio-visual or image output device D1. Through the image processing methods shown in FIG. 8A to FIG. 8C , the problem in the prior art that the display device displays noisy images due to switching of audio, video or image sources can be effectively solved.

Please refer to FIG. 9 , which is a flow chart of another embodiment of the image switching method of the present invention. As shown in Figure 9, basically, steps S10-S18 in this embodiment are similar to the flow chart in Figure 7, the difference between the two is that in this embodiment, the stored first processed image is fixed to be output at least once to the display device, and then output the second processed image formed by the second scaling process on the second image to the display device. For example: in step S26, as shown in FIG. 8B , the image timing control module 203 will first read the output image V2' stored in the storage module 202 and transmit it to the first audio-visual or image output device D1. Next, returning to FIG. 9 , in step S28, the switcher determines whether the number of times the image timing control module 203 outputs the stored output image V2' to the first audio-visual or image output device D1 has reached a specific output number. If not, it means that the specified output times have not been reached, and the method will repeat step S26 until the specified output times are reached. If yes, it means that the specific output times have been reached. Generally speaking, after the specific output times, the second image has completed the second scaling process to form the second processed image. At this time, in step S30, as shown in FIG. 8C , the image timing control module 203 will read the output image V4 from the storage module 202 and output it to the first audio-visual or image output device D1 for the first audio-visual or image output device D1. The image output device D1 plays.

It should be noted that, although in the foregoing description, as shown in FIG. 7 or FIG. 9 , the image processing flow during switching is switched from the image source that needs to be enlarged to the image source that needs to be reduced. However, the actual application is not limited to this case. That is, when the switcher switches between different image sources, the switcher 20 can pre-store the output image output by the image timing control module 203 at a time point before the switch, and the new image can be obtained after the switcher 20 completes the switch. Before normal playback, the switcher 20 outputs the pre-stored output image to the display device. After the processing of the new image is completed, the switcher 20 outputs the new image to the display device. In this way, the problem in the prior art that the display device displays noisy images after the switch completes switching and before the new images can be played normally can be avoided. The so-called normal playback, in one embodiment, the newly switched image needs to be zoomed, so before the zooming process is completed, the pre-stored image is output first, and the zoomed image is output after the zooming process is completed. new image.

For example, in one embodiment, the first scaling process in FIG. 7 may be a process of reducing the image resolution, and the second scaling process may be a process of enlarging the image resolution. In this embodiment, according to the scaling process shown in FIG. 4 and FIG. 5, it can be known that when the first scaling process is to reduce the image resolution, the scaling module 201 will directly receive the input image from the image receiving module 200, and The reduced input image is stored in the storage module 202, and then the image timing control module 203 outputs the reduced input image stored in the storage module 202 to the display device D1. At this time, when the switcher 20 receives the switching signal SW and switches to the image source that needs to be amplified, the scaling module 201 will read the image from the storage module 202 for amplifying processing and then output it to the image timing control module 203 for output to Display device D1, but the enlarging process still needs a period of time to be performed. Therefore, the method utilizes step S16 in FIG. , and then during the scaling module 201 performing the second scaling process (enlarged image processing), the image timing control module 203 first outputs the stored reduced output image to the display device D1, so as to prevent the display device D1 from performing the second scaling in the scaling module 201 There was a problem with displaying a noisy screen during processing (enlarged image processing).

Next, please refer to FIG. 10 , which illustrates another embodiment of the switcher in the video switching system of the present invention. In addition to the aforementioned method of judging whether to perform the image restore process according to the switching signal, whether to perform the image restore operation can also be determined by whether the image receiving module 200 receives a stable image. Since the image receiving module 200 is used to receive the input image transmitted by the image switching module 204, when the image switching module 204 receives the switching signal SW, for example, when switching from the audio-visual or image source S1 to the audio-visual or image source S2, the image The input image received by the receiving module 200 has an unstable frame NS. Therefore, in this embodiment, the image receiving module 200 may determine whether the received input image has an unstable frame NS as a trigger mechanism for whether to store the existing output image back into the storage module 202 .

For example, when the image switching module 204 has not received the switching signal SW, the image receiving module 200 always receives the stable input image output from the audio-visual or image source S1, when the image switching module 204 receives the switching signal SW and When the audio-visual or image source S1 is switched to the audio-visual or image source S2, as long as the image receiving module 200 has not received a stable input image from the audio-visual or image source S2, the image receiving module 200 will determine that the received input images are all If there is an unstable frame NS (for example, caused by resolution change or synchronous signal change, but not limited thereto), at this time, the image receiving module 200 will send a store back signal to the image timing control module 203 . The image timing control module 203 then restores the currently stable output image to the storage module 202 according to the restore signal. In addition, the image timing control module 203 will continue to read the existing images stored back into the storage module 202 before the image receiving module 200 has completely written the stable image output from the audio-visual or image source S2 into the storage module 202. The first processed image is output to a display device to avoid the problem of noisy image output.

When the image receiving module 200 determines that a stable input image has been received from the audio-visual or image source S2 , the input image can be successfully written into the storage module 202 . When the storage module 202 determines that a new input image is completely written into the storage module 202, the storage module 202 will notify the image timing control module 203 to capture the new input image and output it to the display device D1. It should be noted that the following two situations may occur next:

The first is the case of downscaling image processing. At this time, the scaling module 201 receives the stable input image from the audio-visual or image source S2 from the image receiving module 200 and performs a reduction process to form a second processed image, which is then stored in the storage module 202 . Once the storage is successful, the storage module 202 will notify the image timing control module 203 to read the newly stored second processed image and output it directly, so as to complete the seamless and noiseless image source switching procedure.

The second is the case of zooming in on image processing. In this case, the storage module 202 receives a stable input image from the audio-visual or image source S2. Once the storage is successful, the storage module 202 notifies the image timing control module 203 to read the newly stored input image and output it directly. Because it is zooming in, the image timing control module 203 will read the new input image stored in the storage module 202 through the scaling module 201, and after being enlarged by the scaling module 201, the image timing control module 203 will output it to the display device D1, so that Complete the seamless and noise-free video source switching process.

Compared with the prior art, the image switching system, image switching device, and image switching method according to the present invention determine the timing of restoring normal and stable images through a trigger mechanism (such as the judgment of switching signals or the judgment of unstable images), and During the period when the new image provided by the switched audio-visual or image source has not yet reached the normal stable state, provide the restored normal stable image to the display device for display until it is determined that the new image provided by the switched audio-visual or image source has reached normal When in a stable state, a new image is provided to the display device for display, so the image switching system, image switching device, and image switching method of the present invention can effectively avoid the problem that the traditional display device displays a noisy picture during the instantaneous switching process. Realize the fast cut effect of seamless and noise-free screen output.

Through the above detailed description of the preferred embodiments, it is hoped that the features and spirit of the present invention can be described more clearly, rather than limiting the scope of the present invention by the preferred embodiments disclosed above. On the contrary, the intention is to cover various modifications and equivalent arrangements within the scope of the appended claims of the present invention.

Claims (30)

1. A method for image switching, comprising the following steps: receiving a first image; performing a first scaling process on the first image to form a first processed image, and outputting the first processed image to a display device; and During the period of switching from the first image to a second image, the first processed image output to the display device is stored according to a trigger mechanism. 2. The image switching method according to claim 1, wherein the trigger mechanism is a switching signal for switching the first image to the second image, and the image switching method further comprises the following steps: receiving the second image according to the switching signal; and performing a second scaling process on the second image; Wherein, when the second image is subjected to the second scaling process, the stored first processed image is output to the display device; when the second image undergoes the second scaling process to form a second processed image , outputting the second processed image to the display device. 3. The image switching method according to claim 1, wherein the trigger mechanism is a switching signal for switching the first image to the second image, and the image switching method further comprises the following steps: receiving the second image according to the switching signal; outputting the stored first processed image to the display device at least once; performing a second scaling process on the second image to form a second processed image; and After the stored first processed image is output at least once, the second processed image is output to the display device. 4. The image switching method according to claim 2 or 3, wherein the first scaling process is a process of reducing image resolution and the second scaling process is a process of enlarging image resolution; or the The first scaling process is a process of enlarging image resolution and the second scaling process is a process of reducing image resolution. 5. The image switching method as claimed in claim 4, wherein when the resolution of the enlarged image is processed, the first or second image is first stored in a storage module, and then the enlarged image is processed by a scaling module resolution processing, and then output the processed first or second processed image to the display device. 6. The image switching method as claimed in claim 4, wherein when processing the reduced image resolution, the first or second image is first input to a scaling module for processing the reduced image resolution, and then the reduced image resolution is processed. The processed first or second processed image is stored in a storage module, and then output to the display device by the storage module. 7. The image switching method according to claim 1, wherein the trigger mechanism is that when receiving the first image becomes receiving the second image, it is judged that the received second image is an unstable image, and the image The switching method further includes the following steps: outputting the stored first processed image to the display device when it is judged that the received second image is unstable. 8. The image switching method as claimed in claim 7, further comprising the following steps: When the received second image is stable, perform a second scaling process on the second image to form a second processed image; storing the second processed image; and Outputting the stored second processed image to the display device. 9. The image switching method according to claim 7, further comprising the following steps: storing the second image when the received second image is stable; and The stored second image is read and a second scaling process is performed on the second image to form a second processed image and output to the display device. 10. The image switching method according to claim 1, wherein the stored first processed image is an image displayed by the display device. 11. An image switching device, comprising: a storage module; An image receiving module, used for receiving a first image among multiple images; a scaling module, performing a first scaling process on the first image to form a first processed image; and An image timing control module, configured to output the first processed image to a display device; Wherein, during the period of switching from the first image to a second image, the image switching device stores the first processed image output to the display device in the storage module according to a trigger mechanism. 12. The image switching device according to claim 11, wherein the trigger mechanism is a switching signal for switching the first image to the second image, and the image receiving module receives the first image according to the switching signal Two images, the scaling module performs a second scaling process on the second image, and when the scaling module has not completed the second scaling process, the image timing control module outputs the first processed image stored in the storage module to the display device; when the scaling module completes the second scaling process to form a second processed image, the image timing control module outputs the second processed image to the display device. 13. The image switching device according to claim 11, wherein the trigger mechanism is a switching signal for switching the first image to the second image, and the image receiving module receives the first image according to the switching signal Two images, the scaling module performs a second scaling process on the second image, the image timing control module outputs the stored first processed image to the display device at least once, and then outputs the stored first processed image A second processed image formed by going through the second scaling process on the second image at least once is output to the display device. 14. The image switching device according to claim 12 or 13, wherein the first scaling process is a process of reducing image resolution and the second scaling process is a process of enlarging image resolution; or the The first scaling process is a process of enlarging image resolution and the second scaling process is a process of reducing image resolution. 15. The image switching device as claimed in claim 14, wherein when processing the zoomed-in image resolution, the first or second image is first stored in the storage module, and then the zoomed-in image is processed by the scaling module resolution processing, and then output the processed first or second processed image to the display device. 16. The image switching device as claimed in claim 14 , wherein when processing the reduced image resolution, the first or second image is first input to the scaling module for the reduced image resolution processing, and then the reduced image resolution is processed. The processed first or second processed image is stored in the storage module, and then output to the display device by the storage module. 17. The image switching device according to claim 11, wherein the trigger mechanism is to determine that when the image receiving module changes from receiving the first image to receiving the second image, the received second image is unstable image, and when it is determined that the received second image is unstable, the image timing control module reads out the stored first processed image from the storage module and outputs it to the display device. 18. The image switching device according to claim 17, wherein when the image receiving module determines that the received second image is stable, it outputs the second image to the scaling module for performing a first step on the second image. and scaling to form a second processed image, the storage module stores the second processed image, and the image timing control module reads out the second processed image and outputs it to the display device. 19. The image switching device according to claim 17, wherein when the image receiving module determines that the received second image is stable, it stores the second image in the storage module, and the scaling module reads the stored second image. and performing a second scaling process on the second image to form a second processed image for the image timing control module to output to the display device. 20. The image switching device according to claim 11, wherein the stored first processed image is an image displayed by the display device. 21. An image switching system, comprising: at least one display device; a plurality of image sources, each image source is used to provide an image; A switcher, which is respectively coupled with the at least one display device and the plurality of image sources, the switcher includes: a storage module; An image receiving module, used for receiving a first image among multiple images; a scaling module, performing a first scaling process on the first image to form a first processed image; and An image timing control module, configured to output the first processed image to a display device; Wherein, during switching from the first image to a second image, the switcher stores the first processed image output to the display device in the storage module according to a trigger mechanism. 22. The image switching system according to claim 21, wherein the trigger mechanism is a switching signal for switching the first image to the second image, and the image receiving module receives the first image according to the switching signal Two images, the scaling module performs a second scaling process on the second image, and when the scaling module has not completed the second scaling process, the image timing control module outputs the first processed image stored in the storage module to the display device; when the scaling module completes the second scaling process to form a second processed image, the image timing control module outputs the second processed image to the display device. 23. The image switching system according to claim 21, wherein the trigger mechanism is a switching signal for switching the first image to the second image, and the image receiving module receives the first image according to the switching signal Two images, the scaling module performs a second scaling process on the second image, the image timing control module outputs the stored first processed image to the display device at least once within a specific time period, and outputs the stored A second processed image formed by the second scaling process on the second image after the first processed image is outputted to the display device at least once. 24. The image switching system according to claim 22 or 23, wherein the first scaling process is a process of reducing image resolution and the second scaling process is a process of enlarging image resolution; or the The first scaling process is a process of enlarging image resolution and the second scaling process is a process of reducing image resolution. 25. The image switching system as claimed in claim 24, wherein when the resolution of the enlarged image is processed, the first or second image is first stored in the storage module, and then the enlarged image is processed by the scaling module resolution processing, and then output the processed first or second processed image to the display device. 26. The image switching system as claimed in claim 24, wherein when processing the reduced image resolution, the first or second image is first input to the scaling module for the reduced image resolution processing, and then the reduced image resolution is processed. The processed first or second processed image is stored in the storage module, and then output to the display device by the storage module. 27. The image switching system according to claim 21, wherein the trigger mechanism is to judge that when the image receiving module changes from receiving the first image to receiving the second image, the received second image is unstable image, and when it is determined that the received second image is unstable, the image timing control module reads out the stored first processed image from the storage module and outputs it to the display device. 28. The image switching system according to claim 27, wherein when the image receiving module determines that the received second image is stable, it outputs the second image to the scaling module for performing a first step on the second image. and scaling to form a second processed image, the storage module stores the second processed image, and the image timing control module reads out the second processed image and outputs it to the display device. 29. The image switching system according to claim 27, wherein when the image receiving module judges that the received second image is stable, it stores the second image in the storage module, and the scaling module reads the stored second image. and performing a second scaling process on the second image to form a second processed image for the image timing control module to output to the display device. 30. The image switching system of claim 21, wherein the stored first processed image is an image displayed by the display device.