Legacy ImageMagick Discussions Archive

Online it says that you should be able to change the dpi using ImageMagick and the following command:

convert -density 300 -units pixelsperinch circle.png circle.png

but it does not update it (from the Microsoft point of view)

One interesting note: pngcheck says that my output file (circle.png) has a density of 300dpi, but graphic tool (paint) shows the file to be 120 dpi. I need to do some testing to see which is reporting the truth.

So it looks like the meta data on the file is being read differently by different code ...

img2img -version
Version: ImageMagick 6.3.4 05/11/07 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2007 ImageMagick Studio LLC

Files are at:
https://www.dropbox.com/sh/b346uuju803d ... Ntm1a?dl=0

Interesting tool pngcheck. It doesn't seem to like the NULL characters.

File: _out1.png (44988 bytes)
chunk IHDR at offset 0x0000c, length 13
2550 x 3300 image, 24-bit RGB, non-interlaced
chunk pHYs at offset 0x00025, length 9: 11811x11811 pixels/meter (300 dpi)
chunk tEXt at offset 0x0003a ...

I have two versions of the software and they both do the same thing. I am using it on Windows 7 and on Windows Server 2012. I am just using this on PNG files. (PNG to PNG). What I am doing is using another third party product to convert eps and ps files to PNG files. Then I am using this software to ...

I am using Convert from the command line to make changes to a PNG file.
Whenever I add the "-alpha transparent" parameter it changes the density from the original 300 dpi to 120 dpi.
How do I keep the density at 300 dpi? ("-density 300" does not seem to work)

Thanks in advance