APPARATUS, METHOD, AND COMPUTER-READABLE MEDIUM FOR IMAGE PROCESSING USING VARIABLE-PRECISION SHADING

There is described a method of shading a group of pixels in a fragment shader in a raster graphics pipeline. At least one first pilot pixel of the group of pixels is shaded under a first precision. At least one second pilot pixel of the group of pixels is shaded under a second precision. An error value representing a difference between the first and second pilot pixels is calculated. At least one other pixel of the group of pixels is shaded under the first precision if the error value is greater than an error threshold. The at least one other pixel is shaded under the second precision if the error value is smaller than the error threshold.