windows - Max resolution of .bmp file format

Question

I have made a Mandelbrot fractal generator (who hasn't, I know) which can render directly to disk to generate huge fractals.

My first test was a UHD 4k resolution which turned out great (8-bit colour for all of these examples). So I decided to go a little crazy and went 10x bigger in both dimensions, i.e. 38400 x 21600. The resulting file doesn't appear valid in that Photoshop can't open it but even looking at the file properties in Windows Explorer shows that the dimensions/etc are missing.

I thought there was a chance that the limits were 32768 so I tried to go just under that by doing a 30000 x 30000. This still seems to be invalid.

Going down to 10000 x 10000 works fine so I am wondering what the limitations are of the file format?

File size shouldn't be an issue as even the 10x4k resolution file was under 1GB.

Answer 1

It looks the maximum size of BMP can be 32Kx32K and 2Gx2G pixels. Here is the link I found.. http://www.fileformat.info/format/bmp/egff.htm