image-manipulation-notes.txt

# STEPS
# 1. Convert PDF application to set of PNGs
# 2. Convert signature's raw base64 character set into a PNG
# 3. Superimpose signature PNG onto the page needing the signature

# 1. Imagemagick command to convert PDF to PNGs
# Note -- the "-alpha deactivate" option is necessary to make sure the background is not transparent
convert -alpha deactivate -density 300 -depth 8 -quality 85 INPUT.pdf OUTPUT.png

# 2. Decode base64 into png file using CLI
echo QWxhZGRpbjpvcGVuIHNlc2FtZQ== | base64 --decode > FILENAME.png

# 3. Putting signature on the page needing the signature
composite -geometry +31+2700 signature.png page6.png page6-signed.png