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JPG's are often used for web sites and email as they are generally smaller file sizes as they are lossy meaning that some image quality is lost when the JPG is compressed and saved. The resultant 'lossy' file means that quality can never be recovered. The JPG format is often used in digital camera memory cards. The JPG file is a great format as it often manages to compress files to 1/10 of the size of the original file which is especially good for saving on bandwidth.

JPG is a popular graphic format, which is characterized by a high degree of compression, which leads to a decrease in image quality. It uses the technology of encoding of smooth color renditions, providing the ability to reduce the amount of data frequently during the recording of the image. Because of the small size it is requested by the owners of websites, allowing you to save the traffic effectively. It is also frequently used in memory cards of digital video cameras. The JPG algorithm is optimally suitable for compressing photographs and pictures, in which realistic scenes with little contrast of colors are present. It is not recommended to use this format for compression of drawings and various kinds of graphics, since a strong contrast between a number of closely located pixels provokes the appearance of visible artifacts.

JPG is a graphical file format for editing still images, it offers a symmetrical compression technique which is processor intensive and time consiming in both compression and decompression. JPEG is a joint standard of the International Telecommunications Union (ITU-T T.81) and the International Organization for Standardization (ISO 10918-1). JPEG involves a lossy compression mechanism using discrete cosine transform (DCT). Compression rates of 100:1 can be achieved, although the loss is noticeable at that level. Compression rates of 10:1 or 20:1 yield little degradation in image quality.

The procedure for compressing the digital images in JPG format is carried out in several stages. First, the photo is transformed into a color space YCbCr, then it is divided into squares to determine the upper range of the color spectrum. Finally, the colors and brightness are coded. JPEG uses a "lossy" compression system and discrete cosine transform technology. The format acts simultaneously as the standard of ISO and the International Telecommunication Union. The file compression ratio is in the range from 10:1 to 100:1. In this case, the reduction in image quality can vary from insignificant to substantial.

The JPEG Committee

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.tiff

Tiff was originally created by a company called Aldus, and is now owned by Adobe systems, it is a file format for storing images, including line art and photographs. It was created due to the popularity of scanners and was thought-up to become the standard scanned image file format. It is a popular format for high-colour-depth images and it has also been adapted to accommodate greyscale images.

Tiff is widely popular format for storing the color images of high quality with a great depth of color (including graphics and photos) on a wide variety of computer platforms. It can save images in shades of gray. It is created by specialists from Aidus, which later became a part of Adobe Systems. It is used to scan and recognize text files. The extension correctly interacts with most applications that provide graphics. Tiff-files are the main format of ?? NeXSTEP, where the scan-line images of this extension were borrowed from Mac OS.

A TIFF file is made up of many different blocks which define the palette data or the LZW-compressed body among other things. The byte order is either Motorola or Intel depending on the first word. if it is MM, then you have Motorola byte ordering and likewise if it is II it means you have Intel byte ordering. Each TIFF file begins with an image file header which then points to an image file directory which contains the image data and image information.

Tiff-files can be stored in the formats of Intel or Motorola, which is determined by the first word - II and MM respectively. This is due to the peculiarities of these processors: Intel reads and writes numbers from right to left, Motorola in reverse order. The format is cross-platform and does not require specialized software. They are correctly displayed by popular graphic editors like Adobe Photoshop or CorelDRAW Graphics. Tiff-file can be presented in the form of tags that carry information about the image, or a single file executed using the LZW compression algorithm. Each named Tiff data area begins with the image header pointing to the image file in the directory storing the submitted images and information about them.

Aldus, Adobe Systems

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