Method for enhancing local contrast of image

Abstract

The invention discloses a method for enhancing a local contrast of an image. The method comprises the steps of acquiring source gray levels of a first block where a pixel point is located, and a second block and a third block which are adjacent to the first block; acquiring the source gray level of a fourth block opposite to the first block where the pixel point is located; respectively calculating a corresponding linear interpolation according to the source gray levels and distances between the pixel point and the first block, the second block, the third block and the fourth block; calculating non-linear interpolations of the linear interpolations through a non-linear function; and carrying out weighted calculations on the non-linear interpolations to obtain a target gray level of the pixel point. According to the method for enhancing the local contrast of the image, diagonal blocks referenced during adjustment of a local gray level are increased, the relevance of diagonal directionsof the image is effectively reflected, the display effect of the local contrast in a smoothing process is enhanced, the display effect of an edge image is enhanced and the user experience is improved.

Description

technical field [0001] The invention relates to the field of display technology, in particular to a method for enhancing local contrast of an image. Background technique [0002] Image contrast enhancement algorithms have important applications in many occasions, especially in medical images, because visual inspection of medical images is necessary in the diagnosis of many diseases. Due to the limitations of the medical image itself and imaging conditions, the contrast of the image is very low. Therefore, a lot of research has been carried out in this field. This enhancement algorithm generally follows certain visual principles. It is well known that the human eye is sensitive to high-frequency signals (edges, etc.). Although details are often high-frequency signals, they are often embedded in a large amount of low-frequency background signals, making them less visible visually. Therefore, appropriately increasing the high-frequency part can improve the visual effect and...

AI Technical Summary

Problems solved by technology

[0005] However, the bilinear interpolation technology has the following disadvantages: (1) It does not refer to the gray scale of the diagonal block. When there is a large difference in the diagonal block, the displayed image cannot make a corresponding correlation

(2) No detection and enhancement for image edges

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