PCX to HDR Converter
Convert PCX to HDR in your browser. PCX files usually come from DOS paint programs (PC Paintbrush, Deluxe Paint), old games, and fax and scanner software; HDR is the better fit for 3D lighting and environment maps. You get a Radiance RGBE (.hdr) file, with the 8-bit sRGB values converted to linear light. Nothing is uploaded.
- Processed locally
- No upload, no wait
- No sign-up
- No watermark
Drop images here
or choose files · paste with Ctrl/⌘ V
PCX expected · other image formats also work
How to use PCX to HDR
- 1
Add your PCX files: drop them here, choose them, or paste from the clipboard.
- 2
There is nothing to tune: the HDR is written losslessly. Resizing and rotating are under More options if you need them.
- 3
Click Convert. Each file is decoded and encoded in a background thread on this device.
- 4
Download the .hdr files one at a time or together as a ZIP.
Why use Aback Images for pcx to hdr
Where the HDR goes next
HDR opens in Blender, Photoshop, Houdini, Unreal Engine, Unity and Affinity Photo.
HDR next to PCX
Both sides are lossless, so the size depends on how well the HDR encoder handles this picture compared with the PCX's byte-wise run-length encoding.
Written without a lossy pass
The HDR is written losslessly, so the pixels decoded from the PCX arrive unchanged.
Processed on your device
Your images are decoded, edited and encoded inside this browser tab by Web Workers. Nothing is uploaded to a server.
PCX vs HDR
What changes from PCX to HDR
Encoding: the PCX uses byte-wise run-length encoding; HDR uses run-length encoded RGBE scanlines, and the download is a Radiance RGBE (.hdr) file, with the 8-bit sRGB values converted to linear light.
Bit depth: 1, 2, 4 or 8 bits per pixel with a palette, or 24-bit as three 8-bit planes in the PCX; HDR allows an 8-bit mantissa per channel sharing an 8-bit exponent (RGBE), 32 bits per pixel, and the HDR written here has RGBE, 32 bits per pixel.
Colour: a 16 or 256-colour palette, or 24-bit RGB in the PCX; HDR supports linear RGB (or XYZ in the XYZE variant), written here as linear-light RGB.
Metadata: the PCX can carry only a 128-byte header with the resolution; HDR can carry a text header with FORMAT, EXPOSURE and optional comments, but nothing is copied across.
About PCX
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 files usually come from DOS paint programs (PC Paintbrush, Deluxe Paint), old games, and fax and scanner software.
About HDR
Radiance .hdr stores high dynamic range light values, widely used for 3D environment maps and HDRI lighting.
A Radiance file starts with '#?RADIANCE' (or '#?RGBE'), text lines such as FORMAT=32-bit_rle_rgbe and EXPOSURE, a blank line, a resolution line like '-Y 2048 +X 4096', then the scanlines.
When converting PCX to HDR makes sense
HDR is the better choice for 3D lighting and environment maps, while PCX suits DOS-era software, retro games and old fax or scanner tools.
HDR strengths: True high dynamic range; Standard for HDRI environment maps. Drawbacks to weigh: Needs tone mapping to view on normal screens.
Limitations
- DOS art was often drawn for 320×200 screens shown at 4:3, where pixels were slightly taller than wide, so it can look a little squashed on a modern display.
- A palette PCX holds at most 256 colours, so a full-colour target keeps them exactly but adds nothing.
- No range is added: the HDR holds the 8-bit picture in linear light, and nothing in it is brighter than the original white.
- 3D software treats the file as linear light, so an ordinary photo used as an environment map may need its exposure raised to light a scene well.
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Frequently asked questions
Does converting PCX to HDR lose quality?
HDR is written losslessly, so the pixels are stored exactly as decoded.
Does saving as HDR make a real HDRI?
No. A real HDRI is merged from several exposures. This file holds an 8-bit image in linear light, so 3D software reads it correctly, but it has no more range than the source.
Which apps open HDR files?
Blender, Photoshop, Houdini, Unreal Engine, Unity and Affinity Photo. It does not open in web browsers.
Are my images uploaded anywhere?
No. Processing happens inside your browser with WebAssembly and Web Workers. The site only downloads the app code and codecs; your files never leave your device. You can confirm this with the live upload counter on the tool, or in your browser's network panel.
Can I process many files at once?
Yes. Drop a whole selection or folder. Files are processed in parallel on several worker threads, each result can be downloaded on its own, and everything can be saved as one ZIP.
Is it free? Is there a file limit or watermark?
It is free with no account, no watermark and no daily limit. The only limit is your device's memory: very large images (over roughly 100 megapixels) may be refused to keep the tab from crashing.