Tagged Image File Format
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- This article is about TIFF, the computer image format. There is also an article about tax increment financing (TIF).
Tagged Image File Format (abbreviated TIFF) is a raster file format for digital images, created by Aldus for use with PostScript printing and now controlled by Adobe. TIFF has become the de facto standard graphics format for high color depth (32-bit) graphics, is widely used in image manipulation applications such as Photoshop, DTP, and scanning, and can be directly manipulated by PostScript.
TIFF includes a number of options that can be used to include all sorts of image formats in the file; this is the purpose of the "tags" that are included in the header. Many of these tags indicate the simple geometry of the image, like its size, but others define how the data is arranged and various image compression options. For instance, TIFF can be used as a container for JPEG or RLE (run-length encoding) compressed images, and in this respect is completely universal.
However, when TIFF was first introduced, programmers were unwilling to invest the time to support all of the options. As a result the lowest common denominator soon became "the" TIFF, and even today the vast majority of TIFF files, and the code that reads them, are based on a simple 32-bit uncompressed image.
Every TIFF file begins with a 2-byte indicator of byte order: "II" for little endian and "MM" for big endian byte ordering. The following 2 bytes represent the number 42. The number 42 was selected "for its deep philosophical significance". The reading of 42 is dependent on the byte order indicated in the first 2 bytes. The entire file is read based on the indicated byte order.
External links
- Adobe TIFF Resources page (http://partners.adobe.com/public/developer/tiff/index.html): Adobe linking to the specification and main TIFF resources
- LibTIFF Home Page (http://www.remotesensing.org/libtiff/): the most widely used library used for reading and writing TIFF files
- TIFF File Format FAQ and TIFF Tag Reference (http://www.awaresystems.be/imaging/tiff.html): everything you always wanted to know about the TIFF File Format but were afraid to askde:Tagged Image File Format
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