Pixels to correct for the error in each pixel.
Sometimes GIF uses the nearest color to represent each pixel,Īnd sometimes it uses "error diffusion" to adjust the color of nearby Better algorithms search the image to find an optimum
LIST TWO FILE FORMATS FOR PICTURES SOFTWARE
The image contains many colors, software that creates the GIF uses any of severalĪlgorithms to approximate the colors in the image with the limited palette ofĢ56 colors available. The image has fewer than 256 colors, GIF can render the image exactly. GIF creates a table of up to 256 colors from a pool of 16 million. The compression is exactly reversible, so the image is recovered exactly. TIFF usage, it looks for patterns in the image that it can use to compress file (Sometimes a losslessĬompression algorithm called LZW is used, but it is not universally supported.) Most graphics programs that use TIFFĭo not compression. In practice, TIFF is used almost exclusively as a lossless image storageįormat that uses no compression at all. The details of the image storage algorithm are included as part of theįile. TIFF is, in principle, a very flexible format that can be lossless or Better modern cameras can capture even more colors. Since theĮye has trouble distinguishing between similar colors, 24 bit or 16 millionĬolors is sometimes called TrueColor. Or 16 million colors without restriction. Current cards devoteĢ4 bits to each pixel, and are therefore capable of displaying 2 24, Later cards would display 256 simultaneously, any of which could beĬhosen from a pool of 2 24, or 16 million colors.
LIST TWO FILE FORMATS FOR PICTURES PC
Many early PC video cards would support only 16 fixedĬolors. May contain only two colors, such as black and white, and will need only 1 bit Images start with differing numbers of colors in them. To changes in color over a small distance. In contrast, a lossy algorithm might store color informationĪt a lower resolution than the image itself, since the eye is not so sensitive In contrast, lossy algorithms accept some degradation in the image in orderĪ lossless algorithm might, for example, look for a recurring pattern in theįile, and replace each occurrence with a short abbreviation, thereby cutting It looks for moreĮfficient ways to represent an image, while making no compromises in accuracy. You will often hear the terms "lossy" and "lossless" compression.Ī lossless compression algorithm discards no information. To exploit this as a way of reducing file size. If an image has few colors, a file type can be designed Compression schemes can by lossy or lossless.Īnother reason for the many file types is that images differ in the number Compression is a term used to describe ways of cutting the Image files can be quite large, and larger file types mean more disk usage and
Part of the reason for the plethora of file types is the need for compression. Other file types are used to encode digital images. What are they, and how do you choose? These and many
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