In the manual it says I have to create a 128x48 bmp image with 1-bit per pixel, but when i upload it to the phone, it merely displays a full black image.

I've tried:

  • creating the image with gimp, saving it as a 1-bit indexed bmp.
  • convert input.bmp -colors 2 -type Bilevel -depth 1 output.bmp

the latter produces the following output when calling identify output.bmp: output.bmp BMP 128x48 128x48+0+0 1-bit sRGB 2c 914B 0.000u 0:00.000

Which looks completely up to specs to me.

Can someone tell what i'm doing wrong, or give me pointers to debug the problem.


I had the same problem, and then I took a look at the example image they provided in their guide (here: https://supportforums.cisco.com/document/51231/configuring-bmp-logo-spa303-and-spa50xg-ip-phones) by using identify. Turns out their bmp is BMP version 3.

So I re-encoded my image from a monochrome png using : "convert test.png -depth 1 -type Bilevel BMP3:test.bmp" and IT WORKED HALLELUJAH!

So I feel like the 5 hours I wasted on that are completely justified. Peace out.

  • You sir, are my hero! -depth 1 doesn't work for me, though. The image remains 8-bit, i'll probably give this another go next friday! – Bas H Apr 18 '16 at 10:00
  • for me it was: convert test.png -depth 1 -monochrome -colors 2 -type Bilevel BMP3:test.bmp – Bas H Apr 18 '16 at 10:09

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