title_body: How to create Pocketbook logo?
upvoted_answer: I met with same problem on my Pocketbook 912, and after some time I figured out how to solve it. BMP should be in indexed color mode and without compression. ImageMagick by default producing RLE compressed bmp.
  For indexed palette I am using default logo image 1_st.912.bmp.
  
  So if you have image with right resolution you can do this:
  
  $ convert someimage.png \
      -background white \
      -alpha remove \
      -depth 8 \
      -colors 256 \
      -type grayscale \
      -remap 1_st.912.bmp \
      -dither FloydSteinberg \
      -compress none  BMP3:outlogo.912.bmp
  
  
  Here's another example, how I converted OpenBSD's puffy to pocketbook logo.
  
  $ wget -O Puffy.gif http://www.openbsd.org/art/puffy/puf800X689.gif # download image
  $ convert Puffy.gif \
      -background white -gravity center -extent 825x1200  \
      -alpha remove -depth 8 -colors 256 -type grayscale \
      -remap 1_st.912.bmp -dither FloydSteinberg -compress none \
      BMP3:puffy.912.bmp
  
  
  This command will resize canvas, center original image and convert it to supported by pocketbook bmp file. Note: since you have other resolution, you should change 825x1200 string to your device's resolution.