Scale transformation method based on image edge direction

Abstract

The invention discloses a scale transformation method based on an image edge direction, comprising the following steps: (a) acquiring the coordinate positions of points to be interpolated in an original image according to the transformation ratio of the image; (b) judging the direction of each image edge by utilizing the spatial correlation of the vertical direction and the horizontal direction of the image; (c) analyzing interpolation methods suitable for each point to be interpolated according to the judging result of the step (b), i.e. adopting a cubic convolution interpolation method for large-angle edge direction, and adopting a linear interpolation method for small-angle edge direction; and (d) carrying out interpolation operation based on the image edge direction for each pixel point according to the judging results of the step (b) and the step (c). In the invention, by utilizing the spatial correlation of the adjacent pixels of the points to be interpolated, the edge direction information of the image is extracted in a multi-direction and multi-level way, and the judgment is accurate and correct.

Description

technical field [0001] The invention relates to the technical field of format conversion of image and video processing, more specifically, a method for image scale conversion based on edge detection. Background technique [0002] At present, images and videos in various formats are being rapidly disseminated through communication methods such as television broadcasting, broadband networks, and wireless communications. Due to their different sources and application fields, the resolutions of these image and video signals must vary widely. From the smallest resolution of tens of thousands of pixels to resolutions up to a maximum resolution of tens of millions of pixels. On the other hand, various display devices sold in the market, such as LCD, PDP, OLED, E-paper, etc., also have different display resolutions due to their own characteristics and different application places. In this way, for the signal processing system of the display device, since the resolution of the input...

AI Technical Summary

Problems solved by technology

[0003] Traditional image scaling methods, such as neighbor point interpolation, linear interpolation, cubic spline interpolation, etc., the image edges after transformation will appear blurred or jagged, and some scale transformation methods based on image edges, such as the application number of The invention patent of US6832009B1, although the method considers the correlation between the target point and the neighboring points, but the image information it uses is insufficient, which may easily cause misjudgment of the image edge, thereby increasing the glitch and flicker of the image video, and the application number is 200510049595.0 Invention patent, although this method uses a lot of image information, it only judges the direction of the horizontal edge of the image, so there are still problems such as jagged edges in the vertical direction

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