PNG and alpha channels tutorial

Portable Network Graphics (PNG) is a bitmapped image format that employs lossless data compression. PNG was created to improve upon and replace GIF (Graphics Interchange Format) as an image-file format not requiring a patent license.

PNG offers a variety of transparency options. With truecolor and greyscale images either a single pixel value can be declared as transparent or an alpha channel can be added (enabling any percentage of partial transparency to be used). For paletted images alpha values can be added to palette entries. The number of such values stored may be less than the total number of palette entries, in which case the remaining entries are considered fully opaque.

An alpha channel allows you to store transparency in an image. You can then use that image in another way, such as in a video. Using an image with an alpha channel allows you to seamlessly overlay that image over another image or even a video in your video editing program.

The PNG files on this site have transparent backgrounds. They may appear to have a white background when you are saving the image, but once you open the image in your video editor or graphics program, you will see the image has no background. No matter if your video background is white, black, or multicolor, the lower third should blend seamlessly over your video.