PAM to JPG Converter
A .pam file turned up from a graphics tool or a command-line program and you cannot view it. PAM is the newer, more flexible relative of the portable map formats, and few viewers support it. This converter reads the header, decodes the pixels and saves a normal JPG on your device.
Embed this tool on your websiteShow code
Free to use on any site. Paste the code where you want the tool to appear. It runs inside the page; visitors' files are processed in their own browser and are not uploaded.
WordPress and most site builders have a "Custom HTML" block where this code can be pasted. The embed keeps a small link back to CalcMaster.
How to convert PAM to JPG
- Add your PAM files by dropping them, clicking the drop zone or pasting.
- The output format is already set to JPG. Adjust quality or size if you need to.
- Press Convert and compare the original and new size for each file.
- Download each file or all of them as a ZIP.
When to convert, and when not to
- A viewer or an upload form does not accept the .pam extension.
- You need to see what a program that writes PAM files has produced.
- You want to share a picture that contains transparency and need to decide the background first.
- Do not convert to JPG if you need to keep the transparent areas; choose PNG or WebP instead.
What changes
- Greyscale maps stay grey and colour maps stay colour.
- If the PAM carries an alpha channel, transparent parts are filled with the background colour you choose, because JPG cannot store transparency.
- The default background is white; pick another colour in the options if the picture will sit on a dark page.
- Values stored with more than eight bits are scaled to eight bits for the JPG.
- Nothing else from the file header is carried across.
How PAM differs from the other portable maps
PAM stands for portable arbitrary map. Older members of the family each cover one fixed case: black and white, grey or colour. PAM uses a single, more general layout. Its header lists the width, height, the number of values per pixel, the largest value and a label for what those values mean. After the header the pixel data follows without compression.
That flexibility is why PAM can carry an extra channel. A colour PAM may hold red, green, blue and a fourth value for opacity. Many simple tools drop that fourth value, which is one reason PAM exists.
Handling transparency
When the file has an opacity channel, the tool combines it with the background colour you choose before saving the JPG. Fully opaque pixels keep their colour, fully transparent pixels become the background and partly transparent pixels blend between the two. This is the same thing a web page does when it shows a transparent picture on a coloured background.
If you want to keep the transparency, change the output format on the right to PNG or WebP. Both can store it, and the converter then leaves the see-through areas alone.
When the file will not open
PAM files that the tool can read are those whose header describes a normal picture: one value per pixel for grey, three for colour, with or without an extra opacity value. A file that declares an unusual layout, or whose data is shorter than the header promises, produces an error message. That usually means the producing program wrote an unusual variant or the file was cut off.
After a successful conversion you can compare the original and new sizes shown next to each file, and download the results one by one or together as a ZIP.
A greyscale PAM that also has an opacity value is handled the same way as a colour one: the grey shades are blended with your background colour where the picture is partly transparent. The queue shows the final pixel size next to each file, so you can confirm the dimensions before downloading.
Privacy: your files stay on your device
- The tool decodes, resizes and encodes your pictures with your browser. The files are never sent to a server.
- To check it yourself: open the browser developer tools (F12), open the Network tab, convert a file, and look for any request that carries your image. You will see none.
Frequently asked questions
What does PAM stand for?
Portable arbitrary map. It is a general layout for pixel data with a short text header, used by some graphics tools.
My PAM has transparency. What happens?
JPG cannot store it, so the see-through areas are filled with your chosen background colour. Use PNG if you want to keep them.
Which background colour should I choose?
Pick the colour of the page or document where the picture will appear. White is the default.
Does the converter read 16-bit PAM files?
Yes. The larger values are scaled to the eight bits that JPG uses.
Why do I get an error for my file?
The header may describe an unusual layout, or the data may be shorter than the header says. Try writing or downloading the file again.