Convert notes
From raju
Crop a multipage pdf
convert -density 360 -crop 3200x1680+4050+500 'MultiPage.pdf[0]' Picture.png
The image to be cropped is specified as sizeWide x sizeHigh + locationHoriz + locationVert where location is top left of crop.
Ref:
create picture with arbitrary text
convert label:"foo\nbar" empty.jpg