Digital photos are stored as files on memory cards and computer hard disks. They may be saved in various file formats each format has a special file extension. Digital photograph files can be compressed to save storage space and can use a standard or a proprietary format. Digital photos are saved as electronic files on digital media. These digital photograph files are a collection of bytes. JPEG is a standard file format for storing such digital photographs. The JPEG format supports compression and enables very efficient high quality storage of digital photographs. While using the JPEG format any applications from various vendors that adhere to the standard could produce and process JPEG files.
JPEG – Joint Photographic Experts Group
The JPEG file format was designed by a particular industry group for the purpose of storing and compressing high quality digital photographs. Later on JPEG became an ISO standard and it is probably among the most popular formats for storing digital photographs now. JPEG files can also be known easy as JPG files named after their common file extension .JPG. The design goal of this Group was the efficient storage of digital photographic files while keeping their original high quality or quality that is as near as possible to the first one. JPEG files can support lossless compression but because lossless compression is ineffective when compressing digital photographs it is hardly used. Ordinarily JPEG files use loss compression to effectively represent digital photographs.
It is easy to Understand the motivation for this compression by using an example: Digital photographs files are constructed of pixels everyone has a value representing its color and intensity. Each pixel occupies 3 bytes one for Red, one for Green and one for Blue – representing the color and intensity of the pixel. If you take a photograph using a 8 mega pixels digital camera the photograph will have 8000000 pixels each one occupying 3 bytes. The whole file size could be 8000000*3=24000000 or 24Mbytes and how many pictures can 16gb hold. This is a really big file. Big files are tough to control they take a while to send by email, they occupy large storage space and they take longer to load. If that identical file was compressed into a JPEG digital photo file its dimensions would reduce to approximately 3Mbytes – a far more manageable file size.
JPEG files are extremely effective in compressing digital photographs. They are using compression methods which were specifically made for digital photos and benefit from digital photographs features that allow a more efficient representation of pixels. The JPEG format standardized how a digital photography is represented and suggested ways to compress digital photographs. Applying this standard software from one vendor can compress and create a JPEG digital photo file while applications from a different vendor can read and process it. There are lots of distinct compressors implementations that differ in the quality of the compressed photograph. Also – the electronic photograph compressor can be set to various levels of compression.