PSD to PCX Converter

Encoding: the PSD uses raw or RLE (PackBits) channel data, ZIP in some 16 and 32-bit files; PCX uses byte-wise run-length encoding, and the download is a run-length encoded PCX: 8-bit indexed when the image has 256 colours or fewer, otherwise 24-bit RGB.

Bit depth: 8, 16 or 32 bits per channel in the PSD; PCX allows 1, 2, 4 or 8 bits per pixel with a palette, or 24-bit as three 8-bit planes, and the PCX written here has 8-bit indexed or 24-bit RGB. 16 and 32-bit documents are reduced to 8 bits per channel.

Colour: RGB, CMYK, Lab, greyscale, indexed or multichannel in the PSD; PCX supports a 16 or 256-colour palette, or 24-bit RGB, written here as 8-bit sRGB.

Transparency: the PSD stores it as transparent layers plus extra alpha channels; the PCX has none, so transparent areas are filled with the colour you choose.

Other images: the PSD can hold layers, masks, adjustment layers and smart objects; only the main image is converted.

Metadata: the PSD can carry XMP, EXIF, IPTC and ICC in image resource blocks; PCX can carry only a 128-byte header with the resolution, but nothing is copied across.

PSD is Adobe Photoshop's layered working format. It keeps layers, masks and effects, but almost nothing outside Photoshop can display it, so finished designs are exported to PNG or JPG.

A PSD has five sections: a header ('8BPS', channel count, size, depth, colour mode), colour mode data, image resources (thumbnail, ICC, XMP, resolution), layer and mask information, and finally the merged composite image that the Maximize Compatibility option saves.

PSD files usually come from Photoshop and apps that save Photoshop documents, such as Affinity Photo, GIMP, Photopea and Krita.

PCX is the image format of ZSoft's PC Paintbrush, the standard for DOS paint programs, scanners and games before GIF and BMP took over. It compresses with a simple run-length scheme.

A PCX file has a 128-byte header (the byte 0x0A, version, encoding, bits per pixel, image window, DPI, a 16-colour palette and the number of colour planes), then RLE-compressed scanlines; 256-colour files end with the byte 0x0C and a 768-byte palette.

PCX is the better choice for DOS-era software, retro games and old fax or scanner tools, while PSD suits editing in Photoshop.

PCX strengths: Read by most legacy and modern viewers; Simple, lossless run-length compression. Drawbacks to weigh: Poor compression for photographs; No transparency; Obsolete outside retro software.