Grayscale image file format
A Portable Gray Map (PGM) file is a grayscale image that can be encoded with 8 or 16 bits per pixel. A PGM file can be stored in text format (an ASCII data block) or as binary data. This can be determined by the file header.
PGM (Portable Gray Map) files store grayscale 2D images. Each pixel within the image contains only one or two bytes of information (8 or 16 bits). While that might not sound like a lot of information, PGM files can hold tens of thousands of shades — ranging from pure black to white, and every shade of gray in between.
The Export PGM File command allows the user to export any loaded elevation grid data sets to a PGM grayscale grid file. These grid files can be used with any software application that supports PGM files. When selected, the command displays the PGM Export Options dialog which allows the user to setup the export.
Both image viewer and photo-editing programs can convert PGM files into other types of photo files. Open the PGM file and then click Save As. Several options will be available.
Note that you can use pamdepth to convert between a the format with 1 byte per gray value and the one with 2 bytes per gray value. There is actually another version of the PGM format that is fairly rare: "plain" PGM format. The format above, which generally considered the normal one, is known as the "raw" PGM format.
Follow this easy four-step process to convert your images.
Choose one of the hundred image formats, available on our site.
Upload your files using an easy-to-use drag-and-drop uploader interface.
Batch convert uploaded files to the format you need.
Download each converted file separately, or as one zip archive.
File type Checks