-density not working properly

[Andon]

I am not sure if I'm doing something wrong or if ImageMagick is borked, but regardless of how I use the -density command, it doesn't seem to work properly.

Using the following:

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convert -size 1006x720 xc:transparent -pointsize 16 -density 290.286 -draw "text  35,70 'test'" test_text.png

produces text of the proper size and an image of the proper size, but when I open the image in GIMP, it reads it as 72 DPI.

Is this something my end?

[el_supremo]

I tried your command and then did:

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identify -verbose test_text.png

which reports, amongst other things:

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  Resolution: 290x290
  Units: Undefined

If you mean pixels per inch you should do:

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convert -size 1006x720 xc:transparent -pointsize 16 -units pixelsperinch -density 290.286 -draw "text  35,70 'test'" test_text.png

but note that the PNG specification only allows for pixels per centimetre and IM will convert 290.286 ppi to 114.28 ppcm.

Pete

[Andon]

Alright, thanks. I was looking through the documentation - not really reading too much - and there was no -units thing that I had seen, so I just figured that it was just ppi. I'd actually prefer to use ppcm - so rather than -units pixelsperinch it'd be -units pixelspercentimeter ?

[el_supremo]

so rather than -units pixelsperinch it'd be -units pixelspercentimeter ?

Yes.

Pete

[fmw42]

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

[Andon]

Awesome guys. Got around to doing this just now, and it works perfectly. Thanks a lot