PGM File Extension

What is PGM file?

PGM (short for Portable Gray Map) is a file format associated with Netpbm, a bitmap graphics package.

What do PGM files contain?

PGM files store 8- or 16-bit grayscale images. A single PGM file can store multiple such images. Each pixel can take a value from 0 (black) to 65 536 (white).

How is data saved in PGM files?

PGM files can saved data in the following formats:
- text (file header with P2 value), which can only store a single image,
- binary (file header with P5 value), which is capable of storing several images in a single file.

File header also defines height, width, and color depth of the image. He body of the file contains values for each image pixel.

What are PGM files used for?

File with PGM extension is an example of PNM (Portable Anymap) standard implementation. PGM files are chiefly used as an image interchange format. Besides PGM, other implementations are available:
- PBM for storing black-and-white images,
- PPM for storing color images (RGB).

Programs which support PGM file extension

The list that follows enumerates programs compatible with PGM files, divided into 3 categories based on operating system on which they are available. Files with PGM suffix can be copied to any mobile device or system platform, but it may not be possible to open them properly on target system.

Updated: 07/21/2022

How to open file with PGM extension?

There can be multiple causes why you have problems with opening PGM files on given system. Fortunately, most common problems with PGM files can be solved without in-depth IT knowledge, and most importantly, in a matter of minutes. The following is a list of guidelines that will help you identify and solve file-related problems.

Step 1. Get the GIMP

The most common reason for such problems is the lack of proper applications that supports PGM files installed on the system. This issue can be addressed by downloading and installing GIMP or different compatible program, such as ACDSee, PaintShop Pro, Canvas. The full list of programs grouped by operating systems can be found above. If you want to download GIMP installer in the most secured manner, we suggest you visit The GIMP Team website and download from their official repositories.

Step 2. Update GIMP to the latest version

If you already have GIMP installed on your systems and PGM files are still not opened properly, check if you have the latest version of the software. Software developers may implement support for more modern file formats in updated versions of their products. If you have an older version of GIMP installed, it may not support PGM format. The most recent version of GIMP is backward compatible and can handle file formats supported by older versions of the software.

Step 3. Assign GIMP to PGM files

If you have the latest version of GIMP installed and the problem persists, select it as the default program to be used to manage PGM on your device. The method is quite simple and varies little across operating systems.

Change the default application in Windows

• Choose the Open with entry from the file menu accessed by right-mouse clicking on the PGM file
• Next, select the Choose another app option and then using More apps open the list of available applications
• To finalize the process, select Look for another app on this PC entry and using the file explorer select the GIMP installation folder. Confirm by checking Always use this app to open PGM files box and clicking OK button.

Change the default application in Mac OS

• Right-click the PGM file and select Information
• Proceed to the Open with section. If its closed, click the title to access available options
• Select the appropriate software and save your settings by clicking Change all
• A message window should appear informing that This change will be applied to all files with PGM extension. By clicking Continue you confirm your selection.

Step 4. Ensure that the PGM file is complete and free of errors

You closely followed the steps listed in points 1-3, but the problem is still present? You should check whether the file is a proper PGM file. Problems with opening the file may arise due to various reasons.

1. Verify that the PGM in question is not infected with a computer virus

Should it happed that the PGM is infected with a virus, this may be that cause that prevents you from accessing it. Immediately scan the file using an antivirus tool or scan the whole system to ensure the whole system is safe. If the scanner detected that the PGM file is unsafe, proceed as instructed by the antivirus program to neutralize the threat.

2. Ensure the file with PGM extension is complete and error-free

Did you receive the PGM file in question from a different person? Ask him/her to send it one more time. It is possible that the file has not been properly copied to a data storage and is incomplete and therefore cannot be opened. When downloading the file with PGM extension from the internet an error may occurred resulting in incomplete file. Try downloading the file again.

3. Ensure that you have appropriate access rights

Some files require elevated access rights to open them. Log in using an administrative account and see If this solves the problem.

4. Verify that your device fulfills the requirements to be able to open GIMP

The operating systems may note enough free resources to run the application that support PGM files. Close all running programs and try opening the PGM file.

5. Ensure that you have the latest drivers and system updates and patches installed

Up-to-date system and drivers not only makes your computer more secure, but also may solve problems with Portable Gray Map Image file. Outdated drivers or software may have caused the inability to use a peripheral device needed to handle PGM files.

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