An algorithm can be applied to a digital image file to compress it since a smaller file is easier to store and send. Compression techniques are distinguished by whether they remove detail and colour from the image. Lossless techniques compress image data without removing detail; lossy techniques compress image data by removing image detail.

Lossless compression

Lossy compression

Colour modes

Colour monitors, like televisions, use light in red (R), green (G), and blue (B) (RGB) to represent the entire spectrum of colour. In print, the four process pigment colours cyan (C), magenta (M), yellow (Y), and black (K) or (CMYK) are used for four-colour reproduction. These systems, or colour modes, are also referred to by the term "colour space"

RGB

CMYK

Vector and bitmap formats

There are two basic forms of computer graphics, bitmaps and vector graphics: The kind you use determines the tools you choose. Bitmap formats, also known as raster graphics, are used in creating digital photographs, whereas vector formats are used primarily for drawings.