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Digital photos are used as digital files on electronic media. Digital images consist of one pixel with a unique color and intensity. While digital photos must not compressed in most cases they are. Compression is a goal to make the files that are smaller and save space.
A digital photo is a built of pixels. A pixel is a single point on the picture that has a value. A pixel is the value of its color and intensity. In general, each pixel is determined by an RGB value (red, green and blue together, that the color pixels), which is about 3 bytes. Digital photo files can be very large. For example, if you shoot a photo with an 8-megapixel digital camera, the photo of each pixel is a crew 8000000 power 3 bytes. The total size would be 8000000 * 3 = 24000000 or 24Mbytes. However ff compressed with the right technology, this file could be much smaller - about 3Mbytes would be common.
There are essentially two types of compression technologies: lossy and lossless:
Lossless Compression: Lossless compression means that when you compress a file and then decompress - decompress the file would be an exact copy of the original file. With lossless compression, no data are lost in the compression process - the software compression uses a better representation of the data in the file but does not remove all data from one such.
lossy compression: lossy compression means that when you move a file, compresses it and then decompress it - the file would be unpacked somewhat differently than the document. The software compression is not only the file data more efficiently, but it also removes the data that they analyzed as a minor or not important. These data can be removed without hardly noticeable deterioration in the quality of compressed file. The differences between the original file and the file be unpacked smaller and irrelevant for the user.
Lossless compression is usually limited to text and other data, in which all data is equally important. For example, if the compression of the text of this article and later to decompress you wish to specify the original article without words or phrases to the software compression decided that it is not important.
Lossy compression on the other side is usually on digital photos and graphics files. These files contain data, the viewer would not be able to notice when removed. For example, small changes in color in a photograph may not be noticeable. The unpacked file is not exactly the same as the original, but if you both the original and decompressed images side by side to the viewer can not tell the difference. Lossy compression software can be at different compression levels on the basis of data, how much may be lost. At some point to lose too much data is significant and degrades the digital photo quality. Many digital cameras can be the amount of compression from low to high where high compression means smaller files, but less quality and low compression means larger files, but no noticeable deterioration in quality.
Digital photos are almost exclusively using lossy technologies. The reason is that due to the nature of a photo (it includes noise, very minor changes that are difficult to compress, but not important, the view and more) lossless compression technologies are not good at them. On the other hand, lossy compression technologies can be very effective in reducing the digital photo file sizes - sometimes an order of magnitude or more.
This article can be published only if the resource box including the backlink is included. Jacob Georgeson writes business and Internet. More information is available on this site about compression Jacob Georgeson is photography, Internet and financial writer.
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