DDS to PGM Converter

DDS (DirectDraw Surface) is a container format for storing compressed and uncompressed textures, cube maps, volume textures, and mipmap chains, introduced by Microsoft with DirectX 7.0 on September 22, 1999. DDS files are designed for GPU-native consumption: the pixel data is stored in formats that graphics hardware can decompress directly during rendering — primarily S3TC/DXTn block compression (DXT1, DXT3, DXT5), and in later DirectX versions BC4 through BC7 — eliminating the CPU-side decompression step required by formats like PNG or JPEG. The file structure begins with a magic number and a 124-byte header specifying width, height, pixel format, mipmap count, and optional DX10 extended header for newer compression modes, followed by the raw surface data. DDS supports 2D textures, cube maps (six faces for environment mapping), volume/3D textures, and texture arrays, each with pre-computed mipmap chains that allow the GPU to sample appropriately sized versions at different distances. One advantage is rendering performance: because the GPU reads DDS data directly without decompression overhead, texture loading is dramatically faster than with traditional image formats, and the compressed data stays compressed in video memory, allowing more textures to fit in VRAM simultaneously. The format's dominance in game development is another key strength — DDS is the standard texture format for DirectX applications, supported natively by Unreal Engine, Unity, and virtually every PC game engine, as well as by image editors like GIMP (with plugin), Paint.NET, Photoshop (via NVIDIA plugin), and ImageMagick.