Image Formats

Format Notes

PNG (.png)

The format of the desktop tool and of LumiScan Training. Shown and exported as it is.

JPEG (.jpg, .jpeg)

Shown as it is; exported for LumiScan Training as PNG.

BMP (.bmp)

Shown as it is; exported as PNG.

TIFF (.tif, .tiff)

Also multi-page. The browser cannot show TIFF, so the server sends each page as PNG. Exported as PNG.

Annotation files and names

The boxes of an image are in <name>.csv next to it, the save history in <name>.json (see Annotation Files). Two images of a folder must therefore not have the same name without extension: if part_01.png and part_01.jpg are both there, only the PNG is listed (then JPEG, BMP, TIFF). Adding images in the browser skips such an image.

Multi-page TIFF

Every page of a multi-page TIFF is an image of its own:

In the list Name in the REST API Annotation file

scan.tif · page 1

scan.tif#1

scan_page001.csv

scan.tif · page 2

scan.tif#2

scan_page002.csv

scan.tif · page 3

scan.tif#3

scan_page003.csv

A TIFF with a single page is listed as scan.tif with scan.csv. Thumbnails and reduced-resolution copies stored in the file are not pages.

A single page cannot be deleted in the app, because the file holds the other pages. Delete or replace the file in the project folder instead.

Bit depth

8-bit grey and colour images keep their pixels. 16-bit TIFF pages are reduced to 8 bit for display, suggestions and export, by the bit depth they actually use: if the brightest value is at most 1023 they are treated as 10-bit, at most 4095 as 12-bit, at most 16383 as 14-bit, otherwise as 16-bit. A 12-bit camera image stored in 16 bit is therefore shown with its full brightness range instead of nearly black.

In the exports

LumiScan Training reads <name>.png next to each <name>.csv. The export therefore writes JPEG, BMP and TIFF pages as PNG (lossless): part_07.jpg becomes part_07.png, page 2 of scan.tif becomes scan_page002.png. The COCO export keeps PNG and JPEG files and writes BMP and TIFF pages as PNG.