The image compression techniques have their origin in the necessity of reducing the size of the file used to store the image, which is huge when compared to storing text (a 800x600 24 bit color uncompressed image needs 1440000 bytes or 1.37 MB). One of the most popular formats is JPEG (which uses files with JPG or JPEG extensions), which can achieve compression ratios of 10:1 with almost no perceived loss of the image quality.

Depending of the program that you use for saving JPEG images, there are available some options for adjusting the compression of the image. Apart from that options, some programs like Corel PhotoPaint, Paint Shop Pro and IrfanView (this one is freeware) allow choosing the type of image subsampling, also called downsampling.

My Choice : FREEWARE Irfanview

Almost all digital cameras store by default EXIF data in the pictures taken with them. This data include information about the camera configuration and conditions at the time of the photo shot. This information usually takes a lot of space, so make sure that saving this data is disable

d in your graphical application when optimizing JPEG files (e.g.: in a test, an 800x600 JPEG picture saved at 75% quality was reduced from 114 KB to 51 KB after stripping the EXIF information).

IrfanView, a freeware graphic viewer/converter, has a plugin for JPEG lossless transformations that allows stripping this da

ta (and other similar like IPTC information) from a JPEG file without recompressin

g the image itself. In this

way you can remove the unnecessary information while maintaining the original image quality.