Transforming divided image patch data using partial differential equations (PDEs)

摘要

A method of transforming an image file comprises: providing 1901 an image file having plural pixels; dividing the pixels into plural patches 1902; sampling 1903 pixels to generate boundary conditions relating to each patch; deriving 1904 coefficients of a partial differential equation (PDE) solution according to the boundary conditions; and outputting 1905 the coefficients for each patch as a transformed image file. Also claimed is a related image file regeneration method, comprising: receiving data comprising coefficients 1906 for plural patches; generating pixel values 1908 by using the coefficients as a solution to a PDE for each patch; and outputting 1910 the plural pixel values. Offsets 1909 may be applied to generated pixel values. Pixels may relate to plural channels; the dividing may comprise forming pixel patches on a pixel array separately for each channel. Plural boundary selectors may be overlaid onto the pixels, pixels may be sampled and boundary conditions as boundary (closed form) curves may be formed based on sample points. PDE coefficients may be quantised and encoded. The processed image files can comprise vector-based data â including normal maps, height maps and/or displacement maps â one or more colour channels, or a texture file of a graphics object.