.IRS File Extension
File TypeAdobe Save For Web Settings
This file is saved in a binary format, which requires a specific program to read its contents.
What is an IRS file?
Settings file created by Adobe Photoshop and Illustrator; contains settings for the "Save for Web" dialog; stores the image format (GIF, JPEG, PNG-8, PNG-24, or WBMP), quality, size, and other optimization options; enables Web designers to save multiple images that have the same formatting and quality specifications.
You can open the Save for Web dialog in Photoshop CS5 by selecting /Presets/Optimized Settings/ directory.. Photoshop includes several preinstalled IRS files in the