Multiple source images
Only one image is decoded; a concatenated image sequence is not exported as a complete set.
Convert PPM to PGM
- In your browser
- No upload
- Private by design
What happens when you convert PPM to PGM?
Grayscale output
Colour is converted to grayscale using linear-sRGB luminance and the sRGB transfer curve. Colour channels and transparency are not retained.
Lossless sample storage
Netpbm stores these samples without compression. Reducing colour, thresholding or changing maxval can still lose information before storage; text and binary representations change the layout, not its image meaning. PGM can store its supported image samples without lossy compression. This applies after rendering and sample conversion: it does not guarantee preservation of source precision, colour space or document structure, and cannot undo earlier losses.
PPM
Source
PPM
Portable Pixmap
Compression: UncompressedTransparency: NoMetadata: Header, Comments
Portable Pixmap: simple uncompressed raster samples for image-processing pipelines.
Explore PPM format →PGM
Target
PGM
Portable Graymap
Compression: UncompressedTransparency: NoMetadata: Header, Comments
Portable Graymap: simple uncompressed raster samples for image-processing pipelines.
Explore PGM format →Is PPM → PGM right for you?
Good choice when
- PGM fits your delivery use: Grayscale images & masks.
- You can choose the source image or part needed for delivery.
- Your processing pipeline explicitly needs grayscale samples.
- You need lossless storage of the rendered samples supported by PGM.
Probably not when
- You require a complete collection, page set or multipart round trip.
- Colour distinctions carry information you need to retain.
- You expect lossless encoding to restore lost details or editing structure.
- You require identical samples without a defined colour and precision policy.
PPM to PGM conversion details
- Multiple source images
- Only one image is decoded; a concatenated image sequence is not exported as a complete set.
- Grayscale output
- Colour is converted to grayscale using linear-sRGB luminance and the sRGB transfer curve. Colour channels and transparency are not retained.
- Lossless sample storage
- Netpbm stores these samples without compression. Reducing colour, thresholding or changing maxval can still lose information before storage; text and binary representations change the layout, not its image meaning. PGM can store its supported image samples without lossy compression. This applies after rendering and sample conversion: it does not guarantee preservation of source precision, colour space or document structure, and cannot undo earlier losses.
- Sample precision & colour
- Pixel conversion only. Original EXIF, GPS, XMP and ICC profiles are not copied; processing uses 8-bit display pixels.
- Metadata & colour
- Pixel conversion only. Original EXIF, GPS, XMP and ICC profiles are not copied; processing uses 8-bit display pixels.
- Compression
- PPM: Uncompressed → PGM: Uncompressed PPM: Netpbm stores these samples without compression. Reducing colour, thresholding or changing maxval can still lose information before storage; text and binary representations change the layout, not its image meaning. PGM: Netpbm stores these samples without compression. Reducing colour, thresholding or changing maxval can still lose information before storage; text and binary representations change the layout, not its image meaning.
- Colour depth
- PPM: maxval up to 65535 → PGM: maxval up to 65535
- Dimensions
- Rendered image dimensions are retained within the converter limits; this tool does not offer resizing. Orientation handling depends on the source decoder.
- Metadata
- Pixel conversion only. Original EXIF, GPS, XMP and ICC profiles are not copied; processing uses 8-bit display pixels.
Common questions
Will every source image be exported?
Only one image is decoded; a concatenated image sequence is not exported as a complete set.
Will PGM keep the source colours?
Colour is converted to grayscale using linear-sRGB luminance and the sRGB transfer curve. Colour channels and transparency are not retained.
Does lossless output mean an unchanged source?
Netpbm stores these samples without compression. Reducing colour, thresholding or changing maxval can still lose information before storage; text and binary representations change the layout, not its image meaning. PGM can store its supported image samples without lossy compression. This applies after rendering and sample conversion: it does not guarantee preservation of source precision, colour space or document structure, and cannot undo earlier losses.
Are bit depth and colour values guaranteed to match?
Pixel conversion only. Original EXIF, GPS, XMP and ICC profiles are not copied; processing uses 8-bit display pixels.
Will metadata and colour profiles be retained?
Pixel conversion only. Original EXIF, GPS, XMP and ICC profiles are not copied; processing uses 8-bit display pixels.