Auto-regressive edge-directed interpolation with backward projection constraint

摘要

Techniques and tools for interpolation of image/video content are described. For example, a tool such as a display processing module in a computing device receives pixel values of a low-resolution picture and determines an interpolated pixel value between a set of the pixel values from the low-resolution picture. The tool uses auto-regressive edge-directed interpolation that incorporates a backward projection constraint (AR-EDIBC). As part of the AR-EDIBC, the tool can compute auto-regressive (AR) coefficients then apply the AR coefficients to the set of pixel values to determine the interpolated pixel value. For the backward projection constraint, the tool accounts for effects of projecting interpolated pixel values back to the pixel values of the low-resolution picture. The tool stores the interpolated pixel values and pixel values from the low-resolution picture as part of a high-resolution picture. The tool can adaptively use AR-EDIBC depending on content and other factors.

主权项

1. A computer-implemented method of pixel value interpolation, the method comprising;
receiving initial pixel values of a low-resolution picture; determining an interpolated pixel value between a set of the initial pixel values of a local window of the low-resolution picture, wherein the determination of the interpolated pixel value uses auto-regressive edge-directed interpolation that incorporates a backward projection constraint, the backward projection constraint accounting for backward projection error for the initial pixel values of the local window around a position of the interpolated pixel value as a constraint on forward prediction for the interpolated pixel value, including:
computing auto-regressive coefficients from at least some of the initial pixel values of the low-resolution picture that are in the local window around the position of the interpolated pixel value, wherein, for the backward projection constraint, the computing considers effects of applying the auto-regressive coefficients in projection from interpolated pixel values back to the initial pixel values of the local window for comparison of the back-projected pixel values to corresponding ones of the initial pixel values of the local window; andapplying the auto-regressive coefficients to the set of initial pixel values to determine the interpolated pixel value; and storing the interpolated pixel value as part of a high-resolution picture in memory, wherein the high-resolution picture also includes the initial pixel values of the low-resolution picture.