As ever the most common electronic document format, CHM features smooth running and convenient retrieval. While it's a pity that it does not support the popular features such as highlight, annotation and labeling. If there is no alternative PDF edition in hand, then we can use Atop CHM to PDF Converter to convert CHM format ebooks to PDF format.

JPEG Imager is a convenient and easy-to-use, lightweight but practical JPEG, PNG and GIF images batch compression and optimization tool, supports real-time preview and contrast of effects, and allows to customize the compression ratio as need.

Undoubtedly, PNG is the most popular image format in the present network environment, with the characteristics of high fidelity and transparent support, and thus inevitably it has a bigger file size. But as a nondestructive image format, it is more difficult if you want to reduce its file volume without loss in image quality.

For some webmasters or web designers, most often they need to make the webpage image smaller, in order to get a faster network transmission (faster page loading and faster image downloading) and the corresponding lower bandwidth bills.

With the improvement of resolution, the file size of photo taken by digital camera (or even mobile phone) is bigger and bigger (often several MBs), which gives us the inconvenience to upload to web space or transfer (time-consuming). So many people choose to compress the volume or reduce its size of picture, but most software is at the expense of image quality loss, so that the final effect is difficult to satisfy.