Algorithm Research And Hardware Implementation Of Luminance And Color Transient Improvement Of Video Image

Digital video post-processing technology mainly includes two parts of imageformat conversion and image enhancement, it is a kind of digital processing technology,which is proposed based on digital business diversity. Image format conversion cantransform a variety of video input signal into suitable signal for digital TV output.Image enhancement can realize image quality enhancement and improve the viewingeffect of image. The effect of image enhancement technology is becoming more andmore significant. Image enhancement mainly includes Luminance TransientImprovement、Color Transient Improvement、Luminance peaking、Gamma Correction、Flesh Tone Correction. Among them, Luminance Transient Improvement and ColorTransient Improvement is the main research object of image enhancement part and playan important role to enhance image quality.The basic principle of image enhancement is to enhance certain useful informationand inhibit some useless information.It makes the human eyes to watch the image moreclearly. In the image transfer process, because of the loss of high-frequency componentsand the effect of aperture diaphragm, the luminance and color signal will make a certaindelay after transmission and cause image blurring、outline unclear. Simultaneous,transfer receiver realizes frequency receiver in receiving end, it also can cause blurredimages. Especially in Color Transient Improvement, since the color signal is sampledwith sub-sampling techniques, the sampling rate in the horizontal direction is only halfof luminance signal. Because of limited bandwidth the edge of the luminance signal issteeper than the edge of the chrominance signal. Compared to the luminance signal, thedelay of color signal is more prominent. The basic principle of Luminance and ColorTransient Improvement is to reduce transition zone of luminance and color of image.The common algorithm of Luminance and Color Transient Improvement includes:stacking hook edge method and displacement method.Traditional algorithms of Luminance and Color Transient Improvement can achieve luminance and color transient improvement, but there will be unexpected vague pointsand overshoot points after image processing, implementation effect is poor. This paperproposes an improved algorithm of luminance and color transient improvement. Theimage will be filtered to remove Gauss noise. The design uses the nine tap filter toobtain the initial hook signal. At the same time, adding the high-frequency judge toprevent signal processing in the place of rapid changes of luminance or chrominance.According to the size of luminance and color value generate real-time gain signal.Finally, the overshoot module removes the overshoot points. This paper introduces amethod to implement the hardware based on the improved algorithm of luminance andcolor transient. It introduces the function and realization of each module. This design ismade by Hardware Description Language Verilog HDL, it uses the Moldesimsimulation tools to simulate all modules. After the simulation, using the programmabledevelopment software QuartusⅡ integrate the entire design. Using DE2-70FPGAdevelopment board, the result can be observed on the monitor. The results demonstratedthat, this design is fully consistent with the expected, realized effect is better thantraditional algorithm. It realizes luminance and color transient improvement.