While the JPEG images are much more popular with the smartphones cameras or with the web sites, they are highly compressed image formats and are often not used by image editing programs like GIMP or Photoshop. Some of the like the PNG (portable network graphics) images. This is why many of the image editing programs like Paint.net use PNG image format as it can contain the alpha channel or the transparent portions in the images. But this extra data in the PNG images comes at the cost of a much larger file size. If you want to save the PNG image files in such a way that they use the least possible space on the disk, then you can make use of the free PNGmicro program.
PNGmico works like an image format converter and performs a lossless conversion on your PNG images which results in as much as 50% reduction of the size of the file. But this file size reduction varies from one PNG file to another. Some PNG files are reduced by 20% while others by 50% of their original size. PNGmicro contains an option to compress the PNG files even further by a much larger degree using the lossy compression. There is also the possibility of removing embedded graphics in the color profile, and rename files during compression.
For using the PNGmicro is a cinch. All you have to do is drag-n-drop all the PNG files on to the PNGmicro window. After this you can click on the small play button on the top for the conversion and compression process to begin. The compression process takes a little more time for the larger PNG images or the images with higher resolution.
Conclusion: PNGmicro can cut down the file size of the PNG files by as much as half their original size without compromising on the quality of the images. But it can compress the PNG files even further if you choose the lossy compression mode.You can download PNGmicro from http://www.romeolight.com/products/pngmicro/.