Answer: Files which are given the.PGM extension are known as Portable Graymap files Format, however other file types may also use this extension. If you are aware of any additional file formats that use the PGM extension, please let us know. How to open a PGM file: The best way to open an PGM file is to simply double-click it and let the. If your PGM file is related to a piece of hardware on your computer, you might need to update your device drivers associated with that hardware in order to open it. This problem is commonly related to multimedia file types that depend upon a piece of hardware inside of your computer to be successfully opened, such as a sound card or graphics card. You must have one of the programs that can open.PGM files. Once you download and install the.PGM file opener, you will be able to open all.PGM documents. Recommended software programs are sorted by OS platform (Windows, macOS, Linux, iOS, Android etc.) and possible program actions that can be done with the file: like open pgm file, edit pgm file, convert pgm file, view pgm file, play pgm file etc. (if exist software for corresponding action in File-Extensions.org's database).

Pgm File Format

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How To Open Pgm Files

The PGM is the Portable Gray Map. If we want to store a 2d array in C as images in PNG, JPEG, or any other image format, we have to do lots of work to encode the data in some specified format before writing into a file.

The Netpbm format gives an easy and portable solution. The Netpbm is an open source package of graphics program and it is used basically in linux or Unix platform. It also works under Microsoft Windows systems.

Each file starts with a two-byte magic number. This magic number is used to identify the type of the file. The types are PBM, PGM, PPM etc. It also identifies the encoding (ASCII or Binary). The magic number is a capital P followed by a single digit number.

The ASCII encoding allows human readability and easy transfer to other platforms; the binary format is more efficient in file size but it may have native byte-order issues.

Viewsat Pgm Files

How to write PGM files?

• Set the magic number P2
• Add whitespace (Space, Tabs, CRs, LFs)
• Add width, formatted as ASCII character in decimal
• Add Whitespace
• Add height, formatted as ASCII character in decimal
• Add Whitespace
• Put the maximum gray value, again in ASCII decimal
• Add Whitespace
• Width x Height gray values, each in ASCII decimal (Range between 0 and maximum value), separated by whitespace from top to bottom.

Can Windows Open Pgm Files

Example Code

The PGM image is looking like below

Output