What is Windows Icon?
In Windows operational systems, an icon is presented as a graphics file with the “.ico” extension. As a matter of fact, it contains sets of bitmapped images, which has various sizes and values of color depth. There are four sizes used for this: 48x48, 32x32, 24x24, and 16x16. Each Windows XP icon must contain three sets of all aforementioned sizes with the following color depth:
• 24-bit with 8-bit alpha channel (32-bit);
• 8-bit (256 colors) with 1-bit transparency;
• 4-bit (16 colors) with 1-bit transparency;
By the example of the “My Pictures” system folder, the following table shows, what each icon should consist of:
Windows XP supports True Color 32-bit icon, in which 24 bits are allocated for color, and 8 bits are for alpha-channel. Such format allows the system to display icons with smooth edges and mix semitransparent zones with any backgrounds during drawing.
The previous versions of Windows (such as Windows 95, Windows 98, Windows ME, Windows NT, and Windows 2000) support only one 1-bit transparency mask. In these systems, icons are displayed with rough contrasting edges.
Icon Constructor supports generation of icons for Windows XP. All icons, created with the help of the program, have all the dimensions recommended by Microsoft (48x48, 32x32, and 16x16), each of which is presented in all color depths (True Color, 256 colors, and 16 colors). When saving an icon, you can easily include or exclude one or another size, according to your needs.