Open HEIC File

PNG File

PNG is short for Portable Network Graphics and is an image file format which was introduced 1996 with a goal to replace GIF image file format. At this moment together with JPG it is the most widely used image format on the internet. According to the latest statistics it is used on 74.8% of websites on the internet.

PNG is a lossless compression format so it preserves all the detail of the image. This makes it a great choice when working with information where exact reproduction of the original image content is important. It is very effective in storing line drawings, text and graphics in a small file. In such cases comparable JPG file would take more space and produce compression artifacts.

An important difference of PNG in comparison with GIF and JPG is native support of the alpha channel. Alpha channel provides a mechanism for an image to store transparency information. Alpha channel and transparency is especially useful for websites development when images should naturally blend with website background. PNG supports various color schemes including grayscale, 8-bit, 16-bit and indexed.

Interlacing could be used in PNG files to allow loading a lower resolution images until full image file is downloaded. This feature is widely used for downloading PNG files from the internet. Interlacing has negative impact on compression effectiveness.

PNG uses lossless compression algorithm similar to one used by ZIP. To make compression more effective on image data special filter is applied prior to image compression. The goal of filtering is to make color information in the image more compressible.

PNG files are supported by every browser in existence today (IE6 has partial support for PNG, but IE7 provides full PNG support with some issues). Also most of the graphic editors support editing and writing PNG files.