JP2 to PCX Converter
Convert JP2 to PCX in your browser. JP2 files usually come from libraries and digital archives, medical (DICOM) and satellite imaging, and digital cinema packages; PCX is the better fit for DOS-era software, retro games and old fax or scanner tools. You get a run-length encoded PCX: 8-bit indexed when the image has 256 colours or fewer, otherwise 24-bit RGB. Nothing is uploaded.
- Processed locally
- No upload, no wait
- No sign-up
- No watermark
Drop images here
or choose files · paste with Ctrl/⌘ V
JP2 expected · other image formats also work
How to use JP2 to PCX
- 1
Add your JP2 files: drop them here, choose them, or paste from the clipboard.
- 2
Pick the colour that replaces transparent areas, since PCX has none.
- 3
Click Convert. Each file is decoded and encoded in a background thread on this device.
- 4
Download the .pcx files one at a time or together as a ZIP.
Why use Aback Images for jp2 to pcx
Where the PCX goes next
PCX opens in GIMP, IrfanView, XnView, ImageMagick, Paint Shop Pro and DOSBox-era tools.
PCX next to JP2
Both sides are lossless, so the size depends on how well the PCX encoder handles this picture compared with the JP2's wavelet coding: reversible 5/3 for lossless files, irreversible 9/7 for lossy ones.
Written without a lossy pass
The PCX is written losslessly, so the pixels decoded from the JP2 arrive unchanged, apart from precision beyond 8 bits per channel.
Processed on your device
Your images are decoded, edited and encoded inside this browser tab by Web Workers. Nothing is uploaded to a server.
JP2 vs PCX
What changes from JP2 to PCX
Encoding: the JP2 uses wavelet coding: reversible 5/3 for lossless files, irreversible 9/7 for lossy ones; 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: up to 16 bits per channel is common, more is possible in the JP2; 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. 12 and 16-bit JPEG 2000 files are reduced to 8 bits per channel.
Colour: sRGB, greyscale, YCC or a space described by an ICC profile in the JP2; PCX supports a 16 or 256-colour palette, or 24-bit RGB, written here as 8-bit sRGB.
Transparency: the JP2 stores it as an extra component flagged as opacity; the PCX has none, so transparent areas are filled with the colour you choose.
Metadata: the JP2 can carry XML, ICC and resolution boxes; PCX can carry only a 128-byte header with the resolution, but nothing is copied across.
About JP2
JPEG 2000 is a wavelet-based format that can be truly lossless or lossy, handles very high bit depths and huge images, and is used where long-term fidelity matters: archives, medicine, satellites and digital cinema.
A .jp2 file is a box structure: a 12-byte signature box, an 'ftyp' box, a 'jp2h' header box with the size and colour specification, then the 'jp2c' box holding the codestream, which begins with FF 4F FF 51.
JP2 files usually come from libraries and digital archives, medical (DICOM) and satellite imaging, and digital cinema packages.
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.
When converting JP2 to PCX makes sense
PCX is the better choice for DOS-era software, retro games and old fax or scanner tools, while JP2 suits archival masters and specialist imaging.
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.
Limitations
- A JPEG 2000 file may be a lossless master or a lossy derivative; the file does not tell you which at a glance, so keep the original either way.
- Archival scans can be tens of thousands of pixels across, and decoding them needs a lot of memory on a phone.
- PCX's run-length compression suits flat-colour art; photographs barely shrink.
- Transparency is flattened onto the background colour, since PCX has no alpha channel.
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Frequently asked questions
Does converting JP2 to PCX lose quality?
PCX is written losslessly, so the pixels are stored exactly as decoded. 12 and 16-bit JPEG 2000 files are reduced to 8 bits per channel.
What happens to transparency when converting JP2 to PCX?
JP2 stores transparency as an extra component flagged as opacity. PCX has no alpha channel, so transparent pixels are composited onto a solid colour, white unless you pick another. To keep transparency, convert to PNG, WebP or AVIF instead.
Which apps open PCX files?
GIMP, IrfanView, XnView, ImageMagick, Paint Shop Pro and DOSBox-era tools. 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.