KR100238674B1 - Method for processing video data in digital still camera - Google Patents

Abstract

end. The technical field to which the invention described in the claims belongs

The present invention relates to a method for intermediate processing of image data of a digital still camera.

I. The technical problem that the invention is trying to solve

Prior to data compression, CCD (Charge Coupled Device) data is converted into red, green, and blue (R, G, B) and then converted into luminance signal and chrominance signal (Y, U, V). The present invention provides a method for saving memory.

All. Summary of Solution of the Invention

The image sensor data is first converted into red, green, and blue (R, G, B), and the red, green, and blue (R, G, B) are converted into luminance signals and two color difference signals [Y, U, V: Y In an image data intermediate processing method of a digital still camera which performs an intermediate process of performing secondary conversion to = 0.3R + 0.59G + 0.11B, U = RY, V = BY], the X × Y pixels formed by the image sensor A first process of dividing the entire screen data consisting of n into n small blocks of pixels of x '× y', red, green, of pixels of x '× y' for each of the divided small blocks; Performing the first-order transformation forming the blue block, and then performing the second-order transformation to obtain two luminance difference blocks and a luminance signal block composed of pixels x'xy 'from the red, green, and blue blocks. A second process performed sequentially for the blocks, and obtained by each small block in the second process With respect to the dosin arc block and two color difference signal blocks it is characterized in that it comprises a third step of performing data compression.

la. Important uses of the invention

It is used to convert CCD data into R, G and B and then to Y, U and V.

Description

Intermediate processing method of image data of digital still camera {METHOD FOR PROCESSING VIDEO DATA IN DIGITAL STILL CAMERA}

The present invention relates to an intermediate method for processing image data in a digital still camera, and in particular, converting CCD data into red, green, and blue (hereinafter, R, G, and B) prior to data compression. The luminance signal and the two color difference signals (hereinafter referred to as Y, U and V). Y = 0.3R + 0.59G + 0.11B, U = R-Y, V = B-Y] The present invention relates to a method for saving memory capacity required during an intermediate process.

In general, a digital still camera converts CCD data into R, G, and B, and then converts the data back to Y, U, and V, and then compresses the data. This intermediate processing requires more than a certain amount of memory. The principle of constituting the transformation from R, G, B to Y, U, V, that is, a matrix is known.

1 is a block diagram showing the configuration of a digital still video camera.

The CCD 11 is an image sensor that converts an optical signal received through a lens into an electrical signal and outputs the electrical signal. The analog processor 12 latches the signal input from the CCD 11 to double sample and outputs an analog image signal by performing gain, flare and shading correction, and potential gamma correction. The analog / digital converter 13 converts the analog processed image signal into a digital form. The memory controller 19 generates an address, a strobe signal, and the like to control a predetermined memory, modulates the 8-bit digital compressed video signal into 16 bits of a predetermined memory storage form, and outputs the modulated signal. The first memory 20 uses a dynamic RAM (DRAM), and generates the first frame video signal by storing the 16-bit video signal in an amount corresponding to one picture, that is, in units of one frame. The image processor 14 inputs the first frame image signal to perform various processes such as white balance, diller correction, data detection, and gamma correction. The image processor 14 also compresses the various processed image data and outputs a first compressed image signal. The first compressed video signal is inputted back into the first memory 20 and output as a second frame video signal in units of one frame, and the second memory 15 receives and stores the frame video signal. The second memory 16 uses a flash memory. The controller 21 uses a microcomputer, and when the power is always on and detects an input of a key for setting shooting conditions (shooting location, shooting mode, etc.) through the user interface means, that is, the keypad 23, the image processing unit 14 causes the image processing unit 14 to perform a unique operation. Control the overall operation of the digital still camera, such as to initiate the operation. The serial input / output driver 15 is connected to the image processor 14 and the controller 21 to enable data communication with a personal computer. The display unit 22 displays various operation states of the digital still camera under the control of the control unit 21. The timing generator 18 generates various timings necessary for the operation of the camera. The iris controller 17 outputs a signal for adjusting the amount of incident light to the lens 10 under the control of the controller 21. In addition, although not shown, there is a power supply unit for supplying main power or auxiliary power to each part of the camera.

FIG. 2 is a diagram illustrating a conventional intermediate process of image data, in which horizontal and vertical are 640 × 480 based on VGA.

(2a) shows the CCD data, i.e., the screen formed on the CCD 11 of FIG. This screen consists of 640 × 480, or 307,200 bytes, which requires at least 4 megabits of memory. (2b) to (2d) show states in which R, G, and B are generated by processing the CCD data. These screens are 640 x 480 x 3, or 921,600 bytes, requiring at least 8 megabits of memory. (2e)-(2g) show the state which processed Y, U, and V by processing said R, G, and B, respectively. These screens also consist of 640 × 480 × 3, or 921,600 bytes, requiring at least 8 megabits of memory.

As such, the need for at least 8 megabits of memory in the intermediate processing prior to compressing the image data causes various problems in the system implementation.

Accordingly, an object of the present invention is to provide a method for saving the memory capacity required in the intermediate process of converting CCD data to R, G, B and then Y, U, V prior to data compression. have.

In order to achieve the above object, the present invention primarily converts image sensor data into red, green, and blue (R, G, B), and converts the red, green, and blue (R, G, B) signals into luminance signals and two. In the intermediate method of image data of a digital still camera which performs an intermediate process of second-order conversion into color difference signals [Y, U, V: Y = 0.3R + 0.59G + 0.11B, U = RY, V = BY] And a first process of dividing the entire screen data composed of the X × Y pixels formed by the image sensor into n small blocks composed of the pixels of x ′ × y ′, and x '× for the divided small blocks. First-order transform forming a red, green, and blue block consisting of y 'pixels, and then obtaining luminance signal blocks consisting of pixels x' × y 'and two color difference signal blocks from the red, green, and blue blocks. A second process of sequentially performing quadratic transformation on the n small blocks; Article characterized in that it comprises a third step of performing data compression with respect to the luminance signal blocks and two chrominance signal blocks is obtained for each small block in the second course.

1 is a block diagram showing the configuration of a digital still video camera

2 is a diagram illustrating an intermediate image data processing process according to the related art.

3 is a diagram illustrating an intermediate process of image data according to an exemplary embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, numerous specific details such as components of specific circuits are shown, which are provided to help a more general understanding of the present invention, and it is understood that the present invention may be practiced without these specific details. It will be self-evident to those of ordinary knowledge. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

3 is a diagram illustrating an intermediate process of image data according to an exemplary embodiment of the present invention, in which the horizontal and the vertical are 640 × 480 based on VGA.

3A) shows the entire screen made of the CCD data, that is, the X × Y pixels formed in the CCD 11, as in FIG. 2 (2a) described above. This screen consists of 640 x 480 (X = 640, Y = 480), or 307,200 bytes, and therefore requires at least 4 megabits of memory.

(3b) shows the form of dividing the entire screen data composed of the CCD data into n small blocks composed of pixels x'xy '. In the present embodiment, the small block includes 8x8 pixels (x '= 8, y' = 8).

(3c) shows a state in which R, G, and B blocks are generated for any one small block of the above (3b). The R, G, and B blocks also include 8x8 pixels (x '= 8, y' = 8). This block unit processing requires 8x8x3, that is, 192 bytes.

(3d) shows a state in which Y, U, and V blocks are generated for the R, G, and B blocks, respectively. The Y, U, and V blocks also include 8x8 pixels (x '= 8, y' = 8). This block unit processing requires 8 x 8 x 3, that is, 192 bytes (1,536 bits). This can be done without additional memory by utilizing the remaining space in the 4-megabit memory for CCD data storage.

After performing step (3c) for all small blocks, data compression is performed on Y, U, and V blocks obtained for each small block.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by the equivalents of the claims.

As described above, the present invention performs an intermediate process of converting CCD data into R, G, and B, and converts R, G, and B into Y, U, and V. By dividing the data into small block units having a, and processing each small block sequentially, there is an advantage of reducing the amount of memory required in an intermediate process.

Claims (1)

The image sensor data is first converted into red, green, and blue (R, G, B), and the red, green, and blue (R, G, B) are converted into luminance signals and two color difference signals [Y, U, V: Y In the intermediate method of image data of a digital still camera performing an intermediate process of secondary conversion to = 0.3R + 0.59G + 0.11B, U = RY, V = BY], A first process of dividing the entire screen data composed of the X × Y pixels formed by the image sensor into n small blocks composed of the pixels of x ′ × y ′; A first-order transform forming a red, green, and blue block composed of x '× y' pixels is performed on the divided small blocks, and then, from the red, green, and blue blocks to x '× y' pixels. A second process of sequentially performing the second transform operation on the n small blocks to obtain the luminance signal block and the two color difference signal blocks; And a third process of performing data compression on the luminance signal block and the two color difference signal blocks obtained for each small block in the second process.

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