GConvert lets you export any icon from icon resource files to single icon (ICO) files, bitmaps BMP, Adobe
Photoshop™ PSD, PNG, JPEG, GIF files and more thanks to possible external plug-ins.

Just select an icon in the Main Viewer, click “Save”, choose the desired output format and it’s done.

Special enhanced support for importing/exporting PNG files compatible with all standard graphic tools. Alpha channel of 32-bit icons can be embedded into PNG files when exporting and vice-versa. You can also create smaller 8-bit PNG files useful for web pages.

Another example: when saving 32-bit alpha-blended icons to GIF, partial transparency is automatically changed into bit-transparency without losing quality.

Convert several icons in one click with batch conversion: more information here.