Convert Adjoin Will Not Preserve 300dpi

[harlequin516]

I am trying to convert 3 jpgs with 300dpi resolution into a 3 page PDF with 300dpi resolution.
What is the right command line to accomplish this?

This is what I have tried,

Code: Select all

convert -density 300 1.jpg -adjoin 2.jpg -adjoin 3.jpg -density 300 combined.pdf

but `identify combined.pdf` does not show this resolution on the pdf file:

combined.pdf[0] PDF 612x792 612x792+0+0 16-bit Bilevel DirectClass 183KB 0.040u 0:00.009
combined.pdf[1] PDF 612x792 612x792+0+0 16-bit Bilevel DirectClass 183KB 0.020u 0:00.009
combined.pdf[2] PDF 612x792 612x792+0+0 16-bit Bilevel DirectClass 183KB 0.010u 0:00.000

What am I doing wrong?

[fmw42]

I believe that PDFs themselves are vector format and do not actually have a density. If an image is imbedded in the PDF then the image has a density.

I will defer to the experts on this, however.



rose: rose: rose: -density 300 rose.pdf
c-98-234-217-52:~ fred$ idv rose.pdf
Image: rose.pdf
Format: PDF (Portable Document Format)
Class: DirectClass
Geometry: 17x11+0+0
Resolution: 72x72
Print size: 0.236111x0.152778
Units: Undefined