Datastream A sequence of bytes. Deflate The name of the compression algorithm used in standard PNG files, as well as in zip, gzip, pkzip, and other compression programs. Deflate is a member of the LZ77 family of compression methods. Filter A transformation applied to image data in hopes of improving its compressibility. The final digital storage area for the image shown by a computer display.
Software causes an image to appear onscreen by loading it into the frame buffer.
Gamma Informally, a measure of the brightness of mid-level tones in an image. Within this specification, gamma refers specifically to the function from display output to image samples. PNG also permits an alpha sample to be stored for each pixel of a grayscale image. An image representation in which each pixel is represented by a single sample that is an index into a palette or lookup table. The selected palette entry defines the actual color of the pixel.