Page 1 of 1

PixelsPerCentimeter is on by default

Posted: 2008-07-18T09:46:45-07:00
by aegion
PixelsPerCentimeter seems to be on by default, contrary to the documentation:

Code: Select all

mogrify -resample 100x100 -format jpg *.png
creates 254 dpi images, while

Code: Select all

mogrify -units PixelsPerInch -resample 100x100 -format jpg *.png
works as expected.

(Tested with ImageMagick-6.4.2-4-Q16-windows-dll on Windows XP SP3.)

Re: PixelsPerCentimeter is on by default

Posted: 2008-07-18T10:04:09-07:00
by magick
The PNG format does not support pixels per inch, only pixels per centimeter.

Re: PixelsPerCentimeter is on by default

Posted: 2008-07-18T11:00:18-07:00
by aegion
What difference should it make for me how the resolution is stored internally? (In pixels per meter, by the way.) Imagemagick is capable of converting between resolution units, so it shouldn't matter.

Anyway, the implementation disagrees with the documentation, which means one of them has a bug. It's your choice which one. :lol:

Re: PixelsPerCentimeter is on by default

Posted: 2008-07-18T11:26:18-07:00
by magick
Ok, we can't reproduce the problem. We're using ImageMagick 6.4.2-4 and it returns the expected resolution of 100 x 100 for both of your commands.