Enable/disable examination of image pixels.
void pdfSetExamineImagePixels(PDFHandle pdf, int ex)
This function enables (ex = 1) or disables (ex = 0) examination of individual image pixels.

Normally, XpdfAnalyze decompresses images and examines each pixel. This allows it to correctly handle images which, e.g., use only cyan and black, and don't contain any magenta or yellow. To speed up processing, you can tell it not to decompress images, and instead to assume that images use all possible colors in their color space (e.g., CMYK images use all four process colors and DeviceN images use all given custom colors).

The default value is enabled.

/* disable examination of image pixels */ pdfSetExamineImagePixels(pdf, 0);