Portable Network Graphics (PNG) is a lossless raster output format intended to replace GIF. Backed by the World Wide Web Consortium (W3C), the international standards organization for the Web, PNG is ideal for use in both documents and on the Web. PNG creates compact files with compact compression. As a versatile image format, it’s a safe choice that’s right in almost any situation that calls for a raster image. PNG is well-supported by all Web browsers as well as desktop applications such as Microsoft Office.
Most graphics apps, paint programs, screen capture utilities, and web design tools create PNG. You can also convert PDF into PNG using pdf2picture or pdf2image. Utilities like these will convert single files or whole collections at once streamlining the PNG production process. Developer tools are also available to generate PNG from various input sources.
PNG vs GIF
PNG has mostly replaced GIFs for line-art and illustrations. The main advantages of PNG over GIF are:
- support for variable transparency (alpha channel)
- up to 25% smaller file size
- extended color support (32-bit true color vs. 8-bit indexed color palette)
- control over image brightness
- interlacing allows for incremental loading
The only compelling case for using GIFs today if for animations, where it is still the dominant format.
PNG or JPG?
PNG is equally comfortable with high-color graphics. When deciding whether to choose PNG or JPG, there are a few considerations. PNG is ideal for high-color images like scans and photos as well. However, at the high-end, JPG may still be a better choice for detailed photographs and highly detailed original art. It’s good to do a few experiments with your images by converting them to both JPG and PNG-24 and then judge quality versus file size/load time to make your choice.
Support Notes on the PNG format
- Visual Integrity outputs both 8-bit and 24-bit color PNG
- Output to any dpi resolution or pixel dimensions while preserving the aspect ratio
- Source files for conversion to PNG can include vector graphics, raster images, and font text strings
- Advanced anti-aliasing applied during production
- Visual Integrity offers an API and Conversion Server for generating PNG images.
- pdf2picture is a desktop program for converting PDF, EPS and AI into PNGs.