Another problem is that although input.png is black & white, it has a depth of 8. Thresholding first produces a PDF with correct colours and 10x smaller:
input-LZW-depth8.pdf 6289138 input-PNG-depth8.pdf 3285386 input-depth1.pdf 461471
Another problem is that although input.png is black & white, it has a depth of 8. Thresholding first produces a PDF with correct colours and 10x smaller:
input-LZW- depth8. pdf 6289138 depth8. pdf 3285386
input-PNG-
input-depth1.pdf 461471