Image Library convert from JPEG to

Question

I'm attempting to convert a JPEG file with, 200 dpi, to a PDF file, however, when I save the file as a PDF I think it's changing the dpi to 72, and thus making the image larger. I had a similar problem when initially trying to scale my JPEG image to a smaller size, and was able to solve that by specifying the dpi when I save the image.

im = Image.open("Image.jpg")

dpi=im.info['dpi']

if im.size == (2592, 1728):
    out = im.resize((1188,792), Image.ANTIALIAS)
elif im.size == (1728,2592):
    out = im.resize((792,1188), Image.ANTIALIAS)

out.save(project, dpi=dpi)

Now when I try to save this JPEG as a PDF, specifying the dpi doesn't seem to make any difference, and I get an image that is larger than my original that looks like it has a lower dpi. Is there a way to mantain a consistent resolution when converting from JPEG to PDF using PIL? Or is there a better way for me to go about doing this?

This is what I have for converting a directory of files from JPEG to PDF:

for infile in listing:

    outfile = destpath + os.path.splitext(infile)[0] + ".pdf"
    current = path + infile

    if infile != outfile:
        im = Image.open(current)
        dpi=im.info['dpi']

        im.save(outfile, "PDF", Quality = 100)

Answer 1

In the CHANGES file of PIL 1.1.7 sources one can read:

• Added resolution save option for PDF files.

  Andreas Kostyrka writes: I've included a patched PdfImagePlugin.py
  based on 1.1.6 as included in Ubuntu, that supports a "resolution"
  save option. Not great, but it makes the PDF saving more useful by
  allowing PDFs that are not exactly 72dpi.

So you should be able to do:

im.save(outfile, "PDF", resolution=100.0)

(seems to work fine on my Ubuntu box).