What is a PPM file Format, and how do you open it?

What are .PPM files?

PPM means Portable PixMap. It is an ASCII or binary image file format that stores pixel data using a simple structure. It is a raster-based file format that uses color pixels to display visual data and primarily stores digital photographs. 

A PPM image file can be identified using the .PPM extension at the end of the file name. The format's files are ascribed for their simple structural designs represented through uncompressed images that denote a sequence of metadata, color data, and pixel values devoid of complex compression algorithms. 

The simple structures of PPM files make the format transferrable and easily readable using different software, platforms, and programs. This makes the format unique from other formats such as JPG and PNG. For example, every PPM file uses text to store data for a specific image. 

However, in every PPM file, each pixel consists of a definite number from 0 to 65,536 and details concerning the width and height of the image alongside any whitespace information. A PPM file consists of a classification of one or more PPM images. 

The image format's files have no data, padding, or delimiters after, between, or before images. Unlike the PGM format, which only supports grayscale, PPM files support full-color images. PPM format also stores pixel data in a simple structure, making it human-readable, unlike BMP format, which is only universally recognized and supported by operating systems and software applications. 

The format has plain texts, which specify the type of image as 'raw' or ‘plain’, the maximum color value, and the number of rows and columns. A plain PPM file specifies every pixel's color based on ASCII-encoded numbers, whereas the format's 'raw' files stipulate all the integral color pixels using raw binary data.

History of PPM image files

The PPM format was created and launched in the late 1980s by Jef Poskanzer. The developer then incorporated tools to create, read, and view PPM files and images into the Pbmplus, Jef's library of tools for creating and managing PPM, PGM, and PBM images. 

The two types of PPM files or images are Plain and Raw images. When every pixel's color is specified using a triad of ASCII numbers, which specify the red, green, and blue pixel color values, such PPM images are called plain PPMs. The images can be identified using the magic number P3 in the file header.

Conversely, the ‘Raw’ PPM images specify all the pixel colors using raw binary data rather than ASCII-encoded numbers. When users open the ‘raw’ PPM files in a text editor, the PPM's image body appears as prattle rather than a comprehensible sequence of numbers. Such PPM images have the magic number P6 within the file header.

PPM was created as a transitional file format for storing and exchanging image information before being converted into other, more open formats. As such, the PPM files are uncompressed and support 24-bit RGB color profiles. The higher bit depth of PPM files necessitates more storage space.

The PPM file format is mainly used by developers when working with graphics at the elementary stages because it hardly supports any compression technique and utilizes a simple structural design. Although the PPM file format was popular in the 1980s, its popularity has dwindled over the past years with the advent of new file formats such as WEBP and HEIC. 

The PPM format, which belonged to the NetPbm project and gradually became a programming library, is seldom used because its files are incompatible with standard Windows software. 

What are PPM files used for?

PPM files are used to store basic color images. They assist users in identifying the type of file, color matrix, and image dimensions. PPM files support the basic text format, which aids in transferring image information across different platforms. 

Pros and cons of PPM files

PPM files have features that make them ideal for specific projects and unsuitable in some cases. As such, it is imperative to understand the benefits and demerits of the PPM file format before adopting it in a project. 

Advantages of PPM files

1. Simple Structure: Each PPM file has a simple structural design that makes it easily understandable, written, or read. Such simple structures make the PPM files ideal for academic purposes and elementary image editing tasks.
2. Very Portable: All PPM files are highly transferrable and can be opened, viewed, converted, and edited using different applications and operating systems without requiring specialized software.
3. Uncompressed: A PPM file stores uncompressed pixel data, a feature that ensures lossless image quality.
4. A Versatile Format: A PPM file can store many color profiles, including RGB, grayscale, and color images with varying color depths, ranging from 1-bit black and white to high-quality true-color photos, making it ideal for most applications.

Disadvantages of PPM files

1. Uncompressed and Larger Files: The PPM file format stores pixel data and does not require any compression, resulting in larger file sizes than compressed image file types such as PNG or JPEG. 
2. Limited Color Support: PPM file format supports limited data and metadata, including a few color profiles or EXIF data essential for particular use cases, projects, or professional image workflows.

How to Open PPM Files

One can open PPM files using online programs such as ACDSee Photo Studio, Canvas X Pro, Adobe Photoshop with CartaPGM plugin, Corel Paintshop Pro 2023, ImageMagick, GIMP, File Viewer Plus, Netpbm, LibreOffice, and qVew.

To open any PPM file, the users must first download a compatible web graphics application or program to their Windows computer or Mac, such as Gimp or Adobe Photoshop.

Second, open the folder with the file to be opened and right-click on its name. Then, select the 'Open With' tab and double-click on the file format's opening program's name to launch the file. The PPM file will open for viewing, previewing, or editing.

How to Create and Edit PPM Files

You can easily create a PPM file. First, determine the PPM image dimensions in pixels. Second, choose the ideal color depth for your image. Third, assign the pixel values to your PPM files by allocating a suitable color value based on the color depth. Finally, Save the file by choosing the .ppm extension.

To edit a PPM file, download and install your preferred program, such as Photoshop. Launch it, then Select and Double-Click the images to be edited. The chosen PPM file will appear on the Edit Workplace; choose File > Open.

A dialogue box shows the image tonal range in the current settings. Adjust the file's features, and the histogram will be updated automatically. 

How to convert PPM files with Convertjack

Convertjack can help you convert your PPM files to PNG, JPEG, ICO, GIF, EPS, BMP, AVIF, and PDF, among other formats. 

Convertjack provides one of the most modern PPM file converters. It allows users to upload multiple files and transform them into preferred formats. Converting a PPM image to other formats takes four steps.

• Step 1: Upload the PPM image
• Step 2: Choose the desired format to convert to
• Step 3: Press the convert button
• Step 4: Download the converted file for review

Our PPM file converters ensure the process is safe and the final files preserve all details and are well-optimized. If you upload low-quality images, the resulting file will maintain similar file details.