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This is the third and final page of Digital Cameras
This page is about common image file formats.
TIFF - Tag Image File Format
(.TIF file extension, pronounced Tiff) TIFF is the format of choice for archiving important images. TIFF is THE leading commercial and professional image standard. It is the most universal and most widely supported format across all platforms, Mac, Windows, Unix.
JPEG - Joint Photographic Experts Group
(.JPG or .JPEG file extension, pronounced Jay Peg). This is the right format for those photo images which must be very small files, for example, for web sites or for email. The JPG file is wonderfully small, often compressed by 90%, or to only 1/10 of the size of the original data, which is very good when modems are involved. However, this fantastic compression efficiency comes with a high price. JPG uses lossy compression (lossy meaning "with losses"). Lossy means that some image quality is lost when the JPG data is compressed and saved, and this quality can never be recovered.
Graphic Interchange Format (GIF)
(.GIF file extension) There have been raging debates about the pronunciation. The designers of GIF say it is correctly pronounced to sound like Jiff.
GIF was developed by CompuServe to show images online (in 1987 for 8 bit video boards, before JPG and 24 bit color was in use). GIF uses indexed color, which is limited to a palette of only 256 colors. GIF was a great match for the old 8 bit 256 color video boards, but is inappropriate for today's 24 bit photo images.
PNG - Portable Network Graphics
(.PNG file extension, the pronunciation 'Ping' is specifically mentioned in the PNG Specification). PNG is not the number one file format, but you will want to know about it. PNG is not so popular yet, but it's appeal is growing as people discover what it can do.
PNG was designed with the experience advantage of knowing all that went before. The original purpose of PNG was to be a royalty-free GIF and LZW replacement. However PNG supports a large set of technical features, including superior lossless compression. Compression in PNG is called the ZIP method, and is like the 'deflate" method in PKZIP (and is royalty free).
But the big deal is that PNG incorporates special preprocessing filters that can greatly improve the lossless compression efficiency, especially for typical gradient data found in 24 bit photographic images.
It is also the format used within the software of some photo manipulation software such as Serif, Adobe and Fireworks.
BMP - Bitmap
(.bmp file extension). The .bmp format is a standard format for storing
device-independent and application-independent images in Windows. This
format is rather simple and has no any tricky compression algorithms,
so .bmp files are quite large but they are decoded/encoded quicker. It
is a lossless saving process (unlike for example JPEG).
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