php vs. psd

[suwunk]

PHP comes with built-in support to read and write images in many formats using the GD library. However, it does not support the Photoshop image format: PSD.

[FieldODreams]

Which format is better to use when you're storing images you'd later want to use for a website: php or psd? And how can you open php images in the psd format?