PHP将PDF转换为图像-dUseCropBox

Question

I'm trying to convert a PDF to an image and I need to make sure that the -dUseCropBox parameter is specified for when calling Ghostscript. Can this be done?

convert "/var/www/vhosts/site.co.uk/httpdocs/uploads/source_pdf/PP4SDpdf.pdf" -resize 500X500 "/var/www/vhosts/site.co.uk/httpdocs/uploads/image_pdf/SaturdayTest.jpg"

It works well but just need to get the Ghostscript parameter in.

Answer 1

The switch for imagemagick (the convert-command) is:

-define pdf:use-cropbox=true

see http://www.imagemagick.org/Usage/formats/#ps_reading

Answer 2

Is it acceptable for you to run Ghostscript directly (instead of having convert call it anyway) ?

I ask, because convert does not do the PDF => JPEG conversion by itself. It calls Ghostscript as its 'delegate' to do the job. So for convert to work you need to have access to a functional Ghostscript installation on that system anyway... .

But how to add custom parameters to convert s commandline to pass them through to Ghostscript's commandline isn't easy to figure out. Ghostscript's commandline isn't exactly easy either, but at least it is fully documented at a well-known place (see Use.htm , Devices.htm and Ps2pdf.htm there).

Here is a command that would convert your input PDF to a series of JPEGs (one file for each PDF page). I'm assuming Windows -- for Linux just replace the ^ by \\ and gswin32c.exe by gs :

gswin32c.exe ^
  -o "d:/path with spaces/to/output/dir/input_page_%03d.jpeg ^
  -sDEVICE=jpeg ^
  -dJPEQ=95 ^
  -r720 ^
  -g5000x5000 ^
  -dUseCropBox=true ^
  "d:/path/to/input.pdf"

Explanation:

• -dJPEGQ sets the JPEG quality. Accepts integer values in the range 0..100 . Higher values create bigger files... (Ghostscript's default for JPEGQ is set to 75.)
• -r720 sets a (rather high) resolution of 720dpi. Higher values create bigger files... (Ghostscript's default for its jpeg output device would be 72dpi.)
• -g5000x5000 gives the file dimension in pixels . (Note: when decreasing the -r... value you MUST also accordingly decrease the -g... value to keep the same dimension in userspace inches or mm.)

You could also add -dPDFFitPage=true if that is useful for you.