ImageMagick: Is it possible to remove "Crop marks"?

Question

I'm using ImageMagick to create a a thumb of a PDF.

/opt/local/bin/convert \
   "$inputFile[0]"     \
  -geometry 157x200    \
  -colorspace RGB      \
   "$ThumbFile"

But lastly we got PDF with "crop marks" (for bleeding).

Is there an option that I can use to don't take those?

How can I do this?

Example:

I would like to have only the content of the second image.

Answer 1

I ended by indicating to image magick to grab only the trim box:

/opt/local/bin/convert \
  -geometry 157x200    \
  -colorspace RGB      \
  -define pdf:use-trimbox=true \
   "$inputFile[0]"     \   
   "$ThumbFile"