heimaki wrote:i wonder why should i store images in a zip? most modern image formats are compressed already, so i fail to see any advantage of doing so.
The reasons are numerous, and storing images in ZIP or RAR format is not often about compression, but that is also a valid reason for popular image formats that are not compressed.
Often people have a library that consists of many images and it can be efficient to consolidate those images into a ZIP file, much in the same way as a Virtual disk might operate.
For example, someone with a large collection of images may want to consolidate images into a ZIP/RAR file to help mitigate file fragmentation across the drive, and/or to reduce wasted cluster space on a given filesystem.
Also, utilizing ZIP or RAR to compress images that do not support compression or files that need to remain natively uncompressed in a workflow would allow the ability to add transparent compression of images without violating the workflow environment.
There are a number of file formats that can be saved without compression, or that do not support compression, or need to remain uncompressed for compatibility with various other programs. BMP, uncompressed TIFF, uncompressed PNG, TGA, just to name a few.