Sub-pixel rendering with gamma adjustment allows the luminance of the sub-pixel arrangement to match the non-linear gamma response of the human eye's luminance channel. For each of a subset of input sampled data indicating a region of an input image, a gamma-adjusted data value is generated for each input image data value in the subset using a local average of at least two input image data values. A sub-pixel rendering operation uses the subset of gamma-adjusted data values and the subset of input image data values to produce an output data value for each sub-pixel element on the display panel. A plurality of output data values collectively indicates an output image. The gamma adjustment allows the sub-pixel rendering to operate independently of the actual gamma of a display device. The sub-pixel rendering techniques with gamma adjustment may improve image contrast in high spatial frequency portions of an image.