CN108805834A - A kind of image processing algorithm that endoscope is with an automatic light meter - Google Patents

Abstract

The present invention relates to image processing fields, in particular disclose a kind of image processing algorithm that endoscope is with an automatic light meter.When the stick mirror of endoscope is too close to object observing or too far away from object observing, image will appear overexposure, or deficient the case where exposing.The value of the time of integration can be adjusted in real time by the way that the time of integration of COMS in endoscope is substituted into corresponding Gamma functions, and then changes the brightness of image, realize light modulation in real time.

Description

An Image Processing Algorithm for Automatic Light Adjustment of Endoscope

technical field

The invention relates to the technical field of image processing, in particular to an image processing method for automatic light adjustment of an endoscope.

technical background

When a doctor uses an endoscope to observe the internal conditions of a patient, because the rod mirror at the front end of the endoscope needs to move constantly, the distance between the light source and the internal tissues of the human body fluctuates, and some internal areas of human tissues reflect light, so the doctor The image seen on the external screen may be overexposed or underexposed. affect the doctor's diagnosis of the patient. In order to prevent such things from happening, the method of automatic dimming is generally adopted. When the screen is too bright, the system sends an instruction to COMS through the serial port to increase the parameter corresponding to the integration time. On the contrary, when the screen is too dark, the system notifies COMS to decrease the parameter corresponding to the integration time.

Contents of the invention

In order to solve the problem that when the rod scope of the endoscope is too close to or far away from the observation target, there will be overexposure or underexposure, which will affect the doctor’s diagnosis, and provides an image processing algorithm for automatic light adjustment, which can realize Automatically adjust light to eliminate overexposure and underexposure and obtain high-quality images.

In order to solve the problems of the technologies described above, a technical solution adopted in the present invention is:

An image processing method for automatic light adjustment of an endoscope, comprising the following content:

Convert each frame of RGB image collected by the endoscope into a YUV image, the conversion formula is as follows:

Extract the Y component, that is, the brightness component, from the YUV image, and process it through multi-threading. One thread displays, and one thread changes the integration time;

Determine whether the overexposed or underexposed pixels in the Y component exceed the limit value. If it exceeds, substitute the integration time of COMS corresponding to this frame of image into the Gamma function of the corresponding parameter and normalize the value after Gamma transformation to change Integral time, unchanged if not exceeded. The SONY IMX236LLJ-C type COMS integration time range used in this article is 0x0000-0x0465, which is converted to 0-1125 in decimal. The image is the brightest when the integration time is 0, and the image is the darkest when the integration time is 1125. When dimming is required, the following Gamma transformation is performed on each pixel value:

s=r ^0.4

Among them, r is the input pixel value, s is the output pixel value, and the Gamma parameter is 0.4. When brightening is required, the following Gamma transformation is performed on each pixel value:

s=r ^2.5

The Gamma parameter is 2.5. After the Gamma transformation, normalization processing is required, and the processed pixel values are normalized to 0-1125, and finally sent to COMS through the serial port.

The beneficial effect of the present invention is: be different from the situation of prior art:

In the image processing method for automatic dimming of the endoscope, the RGB image collected by the endoscope is first converted into a YUV image, and the Y component is extracted through multi-threading, so that the brightness of the image will not be affected when changing the brightness. normal display. Then determine whether the overexposed or underexposed pixels in the brightness component of the image exceed the standard. If not, the COMS integration time will not be changed. If it exceeds the standard, the COMS integration time will be changed through Gamma change and normalization, and then the brightness of the image will be changed. , remove overexposure and underexposure, and obtain a good video image.

Description of drawings

Fig. 1 is a schematic flow chart of the steps of an endoscope automatic dimming image processing method in an embodiment of the present invention;

Fig. 2 is the Gamma transformation normalization curve adopted;

Fig. 3 is an overexposure picture selected in the embodiment of the present invention;

Fig. 4 is the picture after the automatic dimming of Fig. 3 in the example of the present invention;

Detailed ways

In order to solve the technical problem that the over-exposure or under-exposure of the image in the endoscope during the diagnosis process of the doctor affects the image quality, the present invention provides an image processing method for automatic light adjustment of the endoscope, which can remove the over-exposure and under-exposure Bring the effect to get high quality video images.

In order to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

An image processing method for automatic dimming of an endoscope provided in an embodiment of the present invention, as shown in FIGS. 1-3 , includes: S101, the endoscope collects RGB image signals; One thread output display; S103, convert the collected thread into YUV format; S104, extract the Y component in the YUV format, that is, the brightness component, through another thread; S105, judge whether the Y component is overexposed or underexposed; S106, if there is no overexposure, do not change the integration time of COMS; S107, if overexposure or underexposure occurs, bring the current integration time value into the Gamma transformation to calculate a new integration time value; S108, for The new integration time value is normalized and sent to COMS.

The specific implementation is as follows:

In the first step, the image of the endoscope is collected and transmitted to the backend through COMS, the format is RGB format, and output and displayed through one thread.

The second step is to convert the collected RGB format into YUV format. The conversion formula is as follows:

The third step is to extract the obtained YUV image through one thread and process it.

The fourth step is to judge whether the extracted Y component is over-exposed or under-exposed. If it does not exist, do not change the integration time. If it exists, count each pixel value to determine whether the pixel value is between 40-200. If more than 80% of the pixels are within the interval, it is judged that the image is normal and there is no need to change the integration Time, if it is lower than 80%, further judge the ratio of pixels lower than 40 and higher than 200, which is larger, if the ratio of pixels lower than 40 is larger, it means underexposure, and you need to reduce the COMS integration time through Gamma transformation to increase Brightness, if the proportion of pixels higher than 200 is large, it means overexposure, and you need to increase the COMS integration time through Gamma transformation to reduce the brightness.

In the fifth step, the SONY IMX236LLJ-C type COMS integration time range used in this article is 0x0000-0x0465, which is converted to 0-1125 in decimal. The image is the brightest when the integration time is 0, and the image is the darkest when the integration time is 1125. When dimming is required, the following Gamma transformation is performed on each pixel value:

s=r ^0.4

Among them, r is the input pixel value, s is the output pixel value, and the Gamma parameter is 0.4. When brightening is required, the following Gamma transformation is performed on each pixel value:

s=r ^2.5

The Gamma parameter is 2.5. After the Gamma transformation, normalization processing is required, and the processed pixel values are normalized to 0-1125, and finally sent to COMS through the serial port.

Through the above solution, overexposure and underexposure can be effectively eliminated, and high-quality video images can be obtained.

The above is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process conversion made by using the description of the present invention and the contents of the accompanying drawings, or directly or indirectly used in other related technical fields , are all included in the scope of patent protection of the present invention in the same way.

Claims (4)

1. a kind of image processing algorithm that endoscope is with an automatic light meter, which is characterized in that including following content：

The collected each frame RGB image of endoscope is converted to YUV image, conversion formula is as follows:

Y-component, that is, luminance component is extracted from YUV image, is handled by multithreading, all the way thread display, thread changes all the way Become the time of integration；

Judge overexposure in Y-component or owe whether the pixel exposed is more than limit value, if it exceeds then by this corresponding frame image The time of integration of COMS is updated to the Gamma functions of corresponding parameter and is normalized to change to the value after Gamma transformation The time of integration does not change if being less than.

2. endoscope image processing method with an automatic light meter according to claim 1, which is characterized in that mutual not shadow between thread It rings, is exported not interfering with image during thus with an automatic light meter by the change time of integration, image shows to be not in prolong Late.

3. endoscope image processing method with an automatic light meter according to claim 1, which is characterized in that count each pixel Value, judges whether that pixel value is between 40-200, judges that image is normal if the pixel higher than 80% is within section, The time of integration is had no need to change, the pixel ratio less than 40 and the pixel ratio higher than 200 are further judged if less than 80% That is big for example, if the pixel ratio less than 40 greatly if the COMS times of integration turned down by Gamma transformation increase brightness, if being higher than 200 pixel ratio is then converted by Gamma the i.e. reduction brightness of the COMS times of integration is turned up greatly.

4. endoscope image processing method with an automatic light meter according to claim 1, which is characterized in that the SONY used herein The IMX236LLJ-C type COMS times of integration ranging from 0x0000-0x0465, it is 0-1125 to be converted to the decimal system.Work as the time of integration Image is most bright when being 0, and when the time of integration is 1125, image is most dark.When needing to dim, each pixel value is carried out as follows Gamma is converted：

S=r^0.4

Wherein be r it is input pixel value, s is output pixel value, and Gamma parameters are 0.4.When needing to lighten, to each pixel Value carries out following Gamma transformation：

S=r^2.5

Wherein Gamma parameters are 2.5.It needs to be normalized after having carried out Gamma transformation, treated pixel value It normalizes between 0-1125, COMS is sent to finally by serial ports.