Portable Maps or AnyMaps (PNM) is collective name refering to family of very similar raster file formats. Their format is very simple and most of them contain just two-byte Id, Width, Height, and raster data. Data can be stored in binary format or in text format (whick produces very large files). Most formats can store images with 8 or 16 bit channels but not all viewer and editor programs support 16 bit PNMs (or binary ones). Imaging supports five PNM formats where PBM, PGM, and PPM are quite common but PAM and PFM are somewhat rare.

PBM - Portable Bit Map stores monochrome 1bit images. Raster data can be saved as text or binary data. Either way value of 0 represents white and 1 is black. As Imaging does not have support for 1bit data formats PBM images can be loaded but not saved. Loaded images are returned in ifGray8 format (witch pixel values scaled from 1bit to 8bit).

PBM - Portable Gray Map stores grayscale 8bit or 16bit images. Raster data can be saved as text or binary data.

PPM - Portable Pixel Map stores RGB images with 8bit or 16bit channels. Raster data can be saved as text or binary data.

PAM - Portable Arbitrary Map is more complex format that can store image data formats of PBM, PGM, and PPM formats with optional alpha channel. Raster data can be stored only in binary format.

PFM - Portable Float Map is unofficial extension of PNM format family which can store images with floating point pixels. Raster data is saved in binary format as array of IEEE 32 bit floating point numbers. One channel or RGB images are supported by PFM format (so no alpha).

There is a complete list of data formats supported by PNM file formats, their Imaging equivalents, and load/cave capability.

Format	TImageFormat equivalent	Loading	Saving	Supported By Map Format	1 bit mono	ifGray8	Yes	No	PBM, PAM	1bit mono + alpha	ifA8Gray8	Yes	No	PAM	8 bit grayscale	ifGray8	Yes	Yes	PGM, PAM	16 bit grayscale	ifGray16	Yes	Yes	PGM, PAM	8 bit grayscale + alpha	ifA8Gray8	Yes	Yes	PAM	16 bit grayscale + alpha	ifA16Gray16	Yes	Yes	PAM	24 bit RGB	ifR8G8B8	Yes	Yes	PPM, PAM	48 bit RGB	ifR16G16B16	Yes	Yes	PPM, PAM	32 bit ARGB	ifA8R8G8B8	Yes	Yes	PAM	64 bit ARGB	ifA16R16G16B16	Yes	Yes	PAM	32 bit R FP32	ifR32F	Yes	Yes	PFM	96 bit RGB FP32	ifA32R32G32B32F	Yes	Yes	PFM

When working with PNM files you can find useful some options which can be set by SetOption function and their current values can be get by GetOption function. Or you can set them by modifying properties of TPGMFileFormat and TPPMFileFormat classes.

OptionId	Allowed Values	Usage	ImagingPGMSaveBinary	0 (false) or 1 (true)	If set to True PGM images will be saved in binary format, otherwise they will be saved in text format (which could result in 5-10x bigger file). Default value is 1 (true).	ImagingPPMSaveBinary	0 (false) or 1 (true)	If set to True PPM images will be saved in binary format, otherwise they will be saved in text format (which could result in 5-10x bigger file). Default value is 1 (true).