Image transparency. Get it if you want it

In computer graphics, alpha channel represents transparency information of an image on a per-pixel basis. A value of 100% in the alpha channel gives a fully solid pixel and 0% provides full transparency. Transparent images are useful when you are not certain of the page background color on which your image will be displayed, or you intend to display your image in front of a complex background rather than a single background color. There are a number of image formats that support transparency. TIFF, TGA, PNG, PSD and GIF all support alpha channel but really only PNG and GIF are used for applications and the web. GIF is the original format with transparency support for the web. However, this format uses a special type of alpha channel. Instead of the alpha channel containing degrees of transparency it only has an on/off transparency, meaning you can't have areas of partial transparency. PNG is a newer format developed to overcome many of the limitations of GIF. It supports high color and partial transparency using alpha channel. As well as PNG, TIFF provides support for an embedded alpha channel which represents up to 256 levels of transparency. Images with an embedded alpha channel can be ported to other applications while retaining transparency as long as the other application also supports alpha channels. Among other image formats supporting transparency are BMP, DDS, DICOM, EXR, PSP, PSD, JNG, TGA, etc. ImageConverter Plus supports transparency that completely coincides with the format specification which is a big advantage.