Large JPEG and PNG uploads are resized on boards with little RAM
On a board with less than 1.5 GB of RAM, such as a Raspberry Pi 3, a JPEG or PNG bigger than 1920x1080 is shrunk when you upload it, so the viewer needs much less memory to show a phone photo.
A phone photo is 12 to 50 megapixels, and a 1080p screen shows about 2 of them. From Anthias 2026.08.1, a board with less than 1.5 GB of RAM shrinks a JPEG or PNG upload that has more pixels than a 1920x1080 image down to about that many, keeping its shape. That covers the Raspberry Pi 2, the Pi 3 and 1 GB boards such as a 1 GB Pi 4. A board with more memory leaves your files as they are.
In the project's testing on a 64-bit Raspberry Pi 3, a 6000x4000 photo was stored at 1762x1175, and the viewer used less than half the memory to show it.
Anthias 2026.08.0 started doing this for images it converts to WebP on upload, such as HEIC and TIFF. JPEG and PNG skip that conversion, so until this release they stayed at full size.
What happens to your file
- It keeps its format, and the asset shows as processing until the resize is done.
- A JPEG is saved again at quality 90. A PNG stays lossless.
- A phone photo's rotation is applied to the pixels and its EXIF data is dropped, so it stays upright.
- GIF, WebP and SVG files aren't resized.
A resized PNG can end up larger on disk than the original. A flat graphic with big areas of one color compresses very well at full size and less well once it's scaled down, while a photographic PNG gets smaller. The resize is there to cut the memory the viewer needs to draw the image, so Anthias keeps the resized file either way.