PGM to UYVY Converter

UYVY is a packed pixel format for storing images and video frames in YUV 4:2:2 chroma-subsampled color space, with the UYVY designation indicating the byte ordering within each 4-byte macropixel: U (Cb), Y0, V (Cr), Y1. Each macropixel encodes two horizontal pixels sharing a single pair of chrominance samples (U and V) but retaining individual luminance values (Y0 and Y1), achieving 2:1 horizontal chroma subsampling that reduces data size by 33% compared to full 4:4:4 YUV while maintaining full luminance resolution. The UYVY ordering is specified as a FOURCC code in Microsoft's Video for Windows and DirectShow frameworks, and is commonly used in professional video capture cards, broadcast equipment, and video processing pipelines. UYVY raw files contain no header — the pixel data is a flat sequence of U,Y,V,Y byte quadruplets, requiring external specification of image dimensions. The 4:2:2 subsampling exploits the human visual system's lower spatial resolution for color compared to brightness: the eye notices luminance detail at much higher spatial frequencies than chrominance detail, so sharing color samples between adjacent pixels produces no visible quality loss in practice. One advantage is broadcast-standard compatibility: UYVY's 4:2:2 sampling matches the chrominance structure used in professional video standards (ITU-R BT.601, SDI), making it the natural format for video capture hardware and frame-accurate processing. The format's efficient memory layout is another strength — the packed byte arrangement enables fast DMA transfers between capture hardware and system memory. UYVY data is handled by FFmpeg, ImageMagick, and professional video capture/editing software.