I use GIMP and ImageMagick for static images, if you want dynamic images I suggest you try another method to send image data.
GIMP: Convert the image to "Indexed mode" Image->Mode->Indexed->Use black and white (1-bit) palette. Save as .bmp
ImageMagick: Then use imagemagick's 'convert' program to convert from .bmp to .pcx i.e. convert source.bmp target.pcx
Then you have 1-bit pcx-file you can include in your android app.