PNG Format & libpng Integration Skill (wlframe/C Style)

When to Apply

Use this skill when implementing, integrating, or reviewing PNG read/write C code in wlframe, especially in image/, buffer/, or related modules, or when using libpng for PNG parsing/generation.

PNG Format Essentials

• PNG (Portable Network Graphics) is a lossless, chunk-based bitmap format (signature: 89 50 4E 47 0D 0A 1A 0A).
• Key chunks: IHDR (header), PLTE (palette), IDAT (data), IEND (end), each with CRC.
• Supports multiple color depths, alpha, palette, grayscale, and color.