Temporal Noise Reduction Method for Noisy Image and Related Apparatus

摘要

Determining of still/movement may be performed with reference to quantization noise of a first section to which a first pixel belongs, and for different results of determining of whether the first pixel is in a movement area or a still area, different frame difference thresholds applicable to the movement area and the still area are separately set, and different frame difference calculation manners are used, different blending coefficients applicable to the movement area and the still area are selected according to the different frame difference thresholds applicable to the movement area and the still area and the frame difference calculation manners, and a noise reduction blending manner is selected according to the different blending coefficients applicable to the movement area and the still area, the frame difference calculation manners, and a pixel value of the first pixel in a current frame.

主权项

1. A temporal noise reduction method for a noisy image, comprising:
acquiring quantization noise of a first section of the noisy image, wherein the first section is any one of multiple sections divided from the noisy image; detecting, according to the quantization noise of the first section, pixel positions of all pixels in a movement estimation neighborhood in a next frame after the pixels move from pixel positions in a current frame to the next frame, wherein the movement estimation neighborhood comprises neighbor pixels centered around a first pixel, and wherein the first pixel is any pixel in the first section; determining, according to a pixel position change situation of all the pixels in the movement estimation neighborhood that change from the current frame to the next frame, whether the first pixel is in a movement area or a still area; selecting a first blending coefficient according to a first frame difference of the first pixel and a preset first frame difference threshold when the first pixel is in the movement area; calculating a first noise reduction pixel value corresponding to the first pixel according to the first blending coefficient, a pixel value of the first pixel in the current frame, and a movement compensation pixel value of the first pixel in a previous frame, wherein the first frame difference is the difference between the pixel value of the first pixel in the current frame and the movement compensation pixel value of the first pixel in the previous frame, and wherein the movement compensation pixel value is a pixel value of a corresponding position of the first pixel in the current frame and is obtained after movement estimation and movement compensation are performed based on a noise reduction pixel of the first pixel in the previous frame; selecting a second blending coefficient according to a second frame difference of the first pixel and a preset second frame difference threshold when the first pixel is in the still area; and calculating a second noise reduction pixel value corresponding to the first pixel according to the second blending coefficient, the pixel value of the first pixel in the current frame, and the noise reduction pixel value of the first pixel in the previous frame, wherein the second frame difference threshold is greater than the first frame difference threshold, wherein the second frame difference is the difference between the pixel value of the first pixel in the current frame and the noise reduction pixel value of the first pixel in the previous frame, and wherein the noise reduction pixel value is a pixel value of a corresponding position of the noise reduction pixel of the first pixel in the previous frame.