A valid 1x1 pixel RGB PSD file (base64-encoded):
| Type ID | Name | Description | |---------|------|-------------| | 0 | Raw | Uncompressed (rarely used except for very small images) | | 1 | RLE (Run-Length Encoded) | PackBits compression – efficient for images with large uniform areas. Each scanline is compressed independently. | | 2 | ZIP (without prediction) | Deflate compression (zlib) – slower but higher ratio. | | 3 | ZIP (with prediction) | Applies a delta filter before ZIP – best for continuous-tone images. | photoshop file format
| Problem | Description | |---------|-------------| | | Many layer effects (drop shadow, bevel, pattern overlay) rely on private keys that third-party apps reverse-engineer incompletely. | | Adjustment layer data | Curves, Levels, Selective Color use complex serialized structures that differ across Photoshop versions. | | Smart Objects | Embedded document data (sometimes another full PSD) – correctly updating them requires recursive parsing. | | Text layers | Store both a rasterized preview and a TySh block containing Adobe’s own text engine state (fonts, kerning, OpenType features). | | Layer comps | Snapshots of layer visibility/position – optional but often critical for design workflows. | A valid 1x1 pixel RGB PSD file (base64-encoded):