Image file formats are standardized means of organizing and storing images. Image files are composed of either pixel or vector (geometric) data. So image formats are divided into three groups: raster formats, vector formats and metafile formats (include both vector and bitmap components).
Raster formats store images as bitmap that is a data structure representing a generally rectangular grid of pixels, or points of color. A bitmap is technically characterized by the width and height of the image in pixels and by the number of bits per pixel.
The greater the number of rows and columns is, the greater the image resolution is, and the larger the file is. Also, each pixel of an image increases in size when its color depth increases — an 8-bit pixel (1 byte) stores 256 colors, a 24-bit pixel (3 bytes) stores 16 million colors, the latter is known as truecolor. Image compression uses algorithms to decrease the size of a file.
There are two types of image file compression algorithms: lossless and lossy. Lossless compression algorithms reduce file size without losing image quality, though they are not compressed into a file with the same small size as a lossy compression file. When image quality is valued above file size, lossless algorithms are typically chosen. Lossy compression algorithms take advantage of the inherent limitations of the human eye and discard invisible information.
Most of the commonly used raster image file and metafile formats are supported by AVS Photo Editor:
1 - Dithering is a technique used in computer graphics to create the illusion of color depth in images with a limited color palette. In a dithered image, colors not available in the palette are approximated by a diffusion of colored pixels from within the available palette. The human eye perceives the diffusion as a mixture of the colors within it.
2 - Color map is a matrix of real numbers between 0.0 and 1.0, where each row is an RGB vector that defines one color.
3 - RAW file formats are used by different camera manufacturers as their own proprietary and typically undocumented formats, which can vary from model to model: .crw .cr2 (Canon), .dng (Adobe), .mef (Mamiya), .nef (Nikon), .orf (Olympus), .arw (Sony). The purpose is to save with minimum loss of information the data that are obtained from the sensor, and the conditions surrounding the capturing of the image (the metadata). These files are not yet processed and therefore are not ready to be used with a bitmap graphics editor or printed. Normally, the image is processed by a raw converter where precise adjustments can be made before conversion to a "positive" file format such as TIFF or JPEG for storage, printing, or further manipulation, which often encodes the image in a device-dependent color space.
Please note that AVS4YOU programs do not allow you to copy protected material. You may use this software in copying material in which you own the copyright or have obtained permission to copy from the copyright owner.
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