pngcrush – optimizer for PNG files

Pngcrush is an open source optimizer for PNG (Portable Network Graphics) files. It is a command-line tool.

The main purpose of pngcrush to reduce the size of the PNG IDAT data stream by trying various compression levels and PNG filter methods. It also can be used to remove unwanted ancillary chunks (such as transparency information or textual comments), or to add certain chunks including gAMA, tRNS, and textual chunks.

Ancillary chunks are optional information including transparency (tRNS), gamma (gAMMA), standard RGB color space confor‐ mance (sRGB) or textual information (iTXt, tEXt or zTXt).

Features include:

  • Reduce the size of the image data contained in the IDAT section.
  • Compresses the image with multiple different combinations and then stores the smallest of the resulting files.
  • Remove all the color-correction data (gamma, white balance, ICC color profile, standard RGB color profile) from PNG files.
  • Change the color encoding of an image.
  • Remove ancillary chunks.

Developer: Glenn Randers-Pehrson
License: OSI Approved License

pngcrush is written in C. Learn C with our recommended free books and free tutorials.

Return to Small Image Tools Home Page | Return to Command-Line Image Compression Tools Home Page

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