Getting familiar with TIFF

TIFF was developed as a universal image file format by ‘ADLUS’ (makers of PageMaker) in 1987. The most recent specification, TIFF 6, was released in 1992. Post which ‘ADLUS’ was bought over by ‘ADOBE’ and ‘ADOBE’ holds the copyright for TIFF. TIFF (Tagged Image File Format) is primarily used for raster (A raster graphics image, or bitmap, is a data file representing generally rectangular grid of pixels, or points of color, on a display device) data interchange. Its main strength is that it is platform independent and is supported by numerous image processing applications. It stores much more information as compared to other image formats like jpeg, gif etc. Another important feature of TIFF is that it has the ability to decompose or form the image by tiles rather then scanlines.This permits much more efficient access to large images which have been compressed .Other important difference between TIFF and other image file formats is that TIFF supports multiple images in a single file. Such files are called ‘multi-page’ TIFF and each page, in a multi-page file, meaning each image can be worked on separately. Some of the Colour spaces supported by TIFF are Grey Scale, RGB, and CMYK etc. TIFF is not algorithm specific and supports many algorithms which include – 1. Raw uncompressed, 2. PackBits 3. Lempel-Ziv-Welch (LZW) 4. CCITT Fax 3 & 4 5. JPEG As the name implies, TIFF images makes use of ‘tags’ which are keywords that define the characteristics of the image that is included in the file. For example, a picture of 320 X 240 pixels would include a width tag followed by the number ‘320’ and a height tag followed by number ‘240’. TIFF also supports lossy JPEG compression, but the tiff specifications do not work out correctly with JPEG and hence jpeg is almost never used in TIFF files. TIFF can support any type of image data, including the usual standards like grayscale and truecolor images in various bit depths. TIFF supports maximum of 4GB of raster (compressed) data. Many image file formats have an image header with the fixed fields containing information such as image dimensions, color, space and other specifications. The TIFF file format is different then others because it allows for a flexible set of information fields. The Tags hold in them most fundamental information like image dimensions to massive information like copyrights etc. There also exists additional provision within tiff header for the inclusion of additional tags which can hold more information about the images. KINDS OF TAGS (within Tiff) There are other tags also such as ‘private tags’ and ‘custom tags’ that can be defined to hold the image specific information. TIFF has various string (text) tag types used to store data, including creation software, artist, scanner type and so on. More such tags could be added by defining new tag types. TIFF, which is used for bitmap images, is compatible with a wide range of software applications and can be used across platforms such as Windows, and UNIX. The TIFF format is complex and stores much higher amount of information, so TIFF files are generally much larger than GIF or JPEG files. The provision for storing vector data in TIFF is very less. TIFF image formats is not widely supported by web browsers due to its size. TIFF is still widely accepted as a photograph file standard in printing industry. TIFF with G3 compression is the universal standard for fax and multi-page art documents. Most imaging software’s understand TIFF image format.