FPGA (field programmable gate array)-based analog video ADC (analog to digital converter) automatic adjustment method and device

Abstract

The embodiment of the invention discloses an FPGA (field programmable gate array)-based analog video ADC (analog to digital converter) automatic adjustment method and device. The method comprises the following steps: presetting the ideal field value range; obtaining actual field values of light colors according to the preset obtaining rule; and when the actual field values of the light colors are not in the ideal field value range, adjusting the offset coefficients and gain coefficients corresponding to the light colors according to the preset adjustment rule until the adjusted actual field values of the light colors are in the ideal field value range, wherein the light colors are at least one of red R, green G or blue B. The method and the device disclosed by the embodiment of the invention have the following beneficial effects: digital automatic adjustment can be implemented; the effect precision after adjustment is high; the adjustment results are unified and reliable; and the adjustment time is greatly shortened.

Description

technical field [0001] Embodiments of the present invention relate to the field of image processing, and in particular to an FPGA-based analog video ADC automatic adjustment method and device. Background technique [0002] The video analog front end is an important component of the multimedia processing system. Although the emerging digital interface is becoming more and more popular, the analog video interface still plays an important role in the multimedia application because of its high image quality and low power consumption. . However, the current video processing such as codec, transmission, and image quality optimization are all based on digital, so the front-end analog video requires an analog-to-digital conversion, and the video analog-to-digital converter (ADC, Analog to Digital Converter) is responsible for this working chip. [0003] After the video is AD converted, in order to achieve the best effect, the converted digital quantity needs to truly reflect the s...

AI Technical Summary

Problems solved by technology

However, due to the gain error and offset error of the ADC, the actual relationship between input X and output Y is Y=X*GAIN+OFFSET, where GAIN is the gain coefficient and OFFSET is the offset coefficient. At the same time, due to different customers and different environments, the ADC faces The input range is different, which will lead to the image converted by the ADC, the dark place is brighter, the bright place is darker, the contrast becomes smaller, etc., resulting in image distortion, so the video ADC should adjust the GAIN and GAIN according to the actual user site. OFFSET adjusts in real time, so that the effect of the video after AD conversion is the best

[0004] At present, the commonly used adjustment method is that the engineering service personnel use the customer's signal source to output a gray-scale image on site, and then manually adjust the GAIN and OFFSET of the ADC according to the actual display effect, so that the gray-scale image looks moderate in brightness and the transition of each level is natural. ; However, because the testers modify GAIN and OFFSET according to their own subjective evaluation of the image quality during the adjustment process, the debugging process is very subjective, and the debugging effects of different testers will be different, and the quality of the effect depends on the debugging Due to the experience of personnel, it is difficult to guarantee and unify the effect; in addition, because the output range of different signal sources is different, it is necessary to adjust for different signal sources. After the user replaces the signal source, he needs to re-adjust, which increases the workload.

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