Characteristics of image file formats

What is the diference between storing an image in .jpg, .tif, .bmp formats?

Answer 1

[Walter Roberson]

The different image file formats were invented at different times, to address needs of the day.

In some cases, the need of the day was to produce a patent-free program (e.g., GIF files were widely used for a time, until Compuserve suddenly decided to charge patent royalties.)

In some cases, the need of the day was to allow for larger images than an earlier successful format.

JPEG files implemented a clever compression scheme that reduced visible artifacts nicely for "scene" files.

But JPEG has trouble with sharp edges, and JPEG compression is lossy, so a new scheme with good lossless compression had to be invented for people doing image editing. Image editing also often requires multiple sub-images per file in order to support "layers" during composition, and for performance it was also useful to group the data for image blocks together (think the days of much smaller memory and slower disks) so that someone could concentrate on a section of the overall image without having to read the entire image in to memory. Hence the TIFF format.

Answer 2

[Doug Hull]

http://en.wikipedia.org/wiki/Image_file_formats

Answer 3

[Amith Kamath]

short answer: from MATLAB's perspective, nothing much really. You could work with any of these image formats using imread and so on. The way MATLAB stores them is as a 3D matrix. Apart from this, http://makarandtapaswi.wordpress.com/2009/07/21/jpeg-compression-method/ is a good read about jpeg, and .tif and .bmp are similar, just that the way the image data is encoded varies. The wikipedia pages for these are the best source of info about the compression schemes, but again, from MATLAB's point of view, it does not really matter!