PAM vs PPM
PPM stores three RGB samples per pixel without compression or alpha. It is easy to inspect in processing pipelines, but sacrifices compactness and rich metadata; select it when direct sample interchange is the priority.
Image format
PAM
Portable Arbitrary Map: simple uncompressed raster samples for image-processing pipelines.
Explore the format
Convert PAM to
Choose a target format for your PAM images.
JPEGJPEGPAM → JPEGPNGPNGPAM → PNGWebPWebPPAM → WebPAVIFAVIFPAM → AVIFHEICHEICPAM → HEICHEIFHEIFPAM → HEIF
All 21 conversions
Marked paths may need steps such as flattening, rasterization, tone mapping or animation loss.
Convert to PAM
Choose a source format to convert to PAM.
JPEGJPEGJPEG → PAMPNGPNGPNG → PAMWebPWebPWebP → PAMAVIFAVIFAVIF → PAMHEICHEICHEIC → PAMHEIFHEIFHEIF → PAM
All 36 conversions
GIFGIFGIF → PAMWith caveatTIFFTIFFTIFF → PAMBMPBMPBMP → PAMSVGSVGSVG → PAMICOICOICO → PAMJPEG XLJPEG XLJPEG XL → PAMJPEG 2000JPEG 2000JPEG 2000 → PAMQOIQOIQOI → PAMTGATGATGA → PAMPCXPCXPCX → PAMPPMPPMPPM → PAMPGMPGMPGM → PAMPBMPBMPBM → PAMHDRHDRHDR → PAMWith caveatEXREXREXR → PAMWith caveatPSDPSDPSD → PAMWith caveatPDFPDFPDF → PAMWith caveatDNGDNGDNG → PAMCanon CR2Canon CR2Canon CR2 → PAMCanon CR3Canon CR3Canon CR3 → PAMCanon CRWCanon CRWCanon CRW → PAMNikon NEFNikon NEFNikon NEF → PAMSony ARWSony ARWSony ARW → PAMFujifilm RAFFujifilm RAFFujifilm RAF → PAMOlympus ORFOlympus ORFOlympus ORF → PAMPanasonic RW2Panasonic RW2Panasonic RW2 → PAMPentax PEFPentax PEFPentax PEF → PAMSigma X3FSigma X3FSigma X3F → PAMKodak RAWKodak RAWKodak RAW → PAMHasselblad 3FRHasselblad 3FRHasselblad 3FR → PAM
Marked paths may need steps such as flattening, rasterization, tone mapping or animation loss.
About PAM
Portable Arbitrary Map
PAM extends Netpbm raster interchange with explicit tuple depth and type. Pixels contain a declared number of samples, which can represent grayscale, RGB, alpha-bearing data or an application-defined tuple. This makes channel meaning more explicit than the separate older PBM, PGM and PPM layouts.
A P7 text header declares WIDTH, HEIGHT, DEPTH, MAXVAL and optional TUPLTYPE, followed by binary samples. Values use one or two bytes according to maxval, up to 65535. Defined tuple types include RGB_ALPHA and GRAYSCALE_ALPHA; arbitrary tuples do not guarantee that an image viewer knows how to display them.
Use PAM for channel-aware processing, transparent Netpbm intermediates and agreed custom raster tuples. Storage is uncompressed and does not provide a general ICC/Exif metadata system. Keep tuple meaning, precision and colour interpretation documented; a tool built only for PPM may reject PAM or remove extra channels on export.
Key capabilities
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.
History of PAM
This format belongs to the documented Pbmplus/Netpbm evolution. The history distinguishes the original bitmap idea, later channel models and library development.
PAM compared
Different formats, different trade-offs. Choose for the image and the workflow.
PAM vs PGM
PGM stores one grayscale sample per pixel. It is suitable for grayscale processing and masks; exporting a colour image requires a deliberate luminance conversion and removes colour information.
PAM vs PBM
PBM stores only black and white, one bit per pixel in its binary form. It fits bitonal masks and line art; tonal images need thresholding or dithering, so gradients cannot remain as continuous gray levels.
PAM vs PNG
PNG preserves decoded pixels losslessly and can carry alpha. It is useful for transparent graphics and screenshots; it does not preserve editable document layers or camera sensor data, and photographic files can be large.
PAM FAQ
What does this format store?
PAM extends Netpbm raster interchange with explicit tuple depth and type. Pixels contain a declared number of samples, which can represent grayscale, RGB, alpha-bearing data or an application-defined tuple. This makes channel meaning more explicit than the separate older PBM, PGM and PPM layouts.
How does compression affect quality?
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.
Does every PAM contain alpha?
No. Alpha depends on DEPTH and TUPLTYPE, for example RGB_ALPHA. An arbitrary fourth sample is not automatically alpha unless the tuple definition says so.
What should I check before opening the file?
Check the magic number, sample precision and tuple or channel meaning. Many simple readers accept only one binary image and 8-bit samples even though the specifications permit more.
What changes when I export to another format?
Preserve maxval and colour interpretation when creating the rendered output. Grayscale and bitonal targets remove information deliberately; alpha requires an alpha-bearing tuple or a separate mask. Optional comments may not transfer.
When is this format useful?
Use PAM for channel-aware processing, transparent Netpbm intermediates and agreed custom raster tuples. Storage is uncompressed and does not provide a general ICC/Exif metadata system. Keep tuple meaning, precision and colour interpretation documented; a tool built only for PPM may reject PAM or remove extra channels on export.