Bitmap to Icon Wizard allows you to create high quality icons of all sizes from image files of the bitmaps type. The program has support for generating icons with transparency effects, even 32-bit ones, as long as the bitmap has a well-defined background color.
Bitmap to Icon Wizard has support for up to four color depths (32-bit with alpha channel, 24-bit, 8-bit, and 4-bit) and five possible icon sizes: 256x256, 48x48, 32x32, 24x24, and 16x16. The application uses octets to generate 256 color images, through the Floyd-Steinberg method. Of course, you can always choose what depth of color and size you will use in the icon you are creating.
You can free download Bitmap to Icon Wizard 32, 64 bit and safe install the latest trial or new full version for Windows 10 from the official site.