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jpegtran transforms JPEG data without reencoding (here with user interface CropGUI). The command-line program jpegtran provides several features for reformatting and recoding the representation of the DCT coefficients, for transformation of actual image data and for discarding auxiliary data in JPEG files, respectively.
JPEG 2000 (JP2) is an image compression standard and coding system. It was developed from 1997 to 2000 by a Joint Photographic Experts Group committee chaired by Touradj Ebrahimi (later the JPEG president), [1] with the intention of superseding their original JPEG standard (created in 1992), which is based on a discrete cosine transform (DCT), with a newly designed, wavelet-based method.
Many of the techniques of digital image processing, or digital picture processing as it often was called, were developed in the 1960s, at Bell Laboratories, the Jet Propulsion Laboratory, Massachusetts Institute of Technology, University of Maryland, and a few other research facilities, with application to satellite imagery, wire-photo standards conversion, medical imaging, videophone ...
In contrast, lossy compression (e.g. JPEG for images, or MP3 and Opus for audio) can achieve much higher compression ratios at the cost of a decrease in quality, such as Bluetooth audio streaming, as visual or audio compression artifacts from loss of important information are introduced.
A TIFF file contains one or several images, termed subfiles in the specification. The basic use case for having multiple subfiles is to encode a multipage telefax in a single file, but it is also allowed to have different subfiles be different variants of the same image, for example scanned at different resolutions.
For example, a raster named mymap.jpg should have a world file named mymap.jpgw. An alternative file naming convention that uses a three-character extension to conform to the 8.3 file naming convention uses the first and last character of the raster file's extension, followed by "w" at the end.
This is the normalization used by Matlab, for example, see. [99] In many applications, such as JPEG, the scaling is arbitrary because scale factors can be combined with a subsequent computational step (e.g. the quantization step in JPEG [100]), and a scaling can be chosen that allows the DCT to be computed with fewer multiplications. [101] [102]
This method usually increases the global contrast of many images, especially when the image is represented by a narrow range of intensity values. Through this adjustment, the intensities can be better distributed on the histogram utilizing the full range of intensities evenly.