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Photo from Digital Camera Always Saves at 72 Density

Posted: 2008-06-16T20:35:30-07:00
by markurxn
I'm trying to save a photo at 300 density. I'm using the command

convert -density 300 photo.jpg -resize 150x122 photo.png

but the photo is always saved at 72 dpi. If I open this photo in photoshop, save as another name without any other file modifications and rerun the command above, the resized png has a 300 dpi.

What gives?

Image

Re: Photo from Digital Camera Always Saves at 72 Density

Posted: 2008-06-16T20:40:10-07:00
by fmw42
try

convert photo.jpg -resize 150x122 -density 300 photo.png


Note: your input resolution is 180 not 72

convert dinkey38.jpg -verbose info:
Image: dinkey38.jpg
Format: JPEG (Joint Photographic Experts Group JFIF format)
Class: DirectClass
Geometry: 2048x1536+0+0
Resolution: 180x180
Print size: 11.3778x8.53333
Units: PixelsPerInch


If I do:
convert dinkey38.jpg -resize 150x122 -density 300 tmp.png

then afterwards the resolution is 300

convert tmp.png -verbose info:
Image: tmp.png
Format: PNG (Portable Network Graphics)
Class: DirectClass
Geometry: 150x113+0+0
Resolution: 300x300
Print size: 0.5x0.376667
Units: PixelsPerInch

Re: Photo from Digital Camera Always Saves at 72 Density

Posted: 2008-06-16T20:56:01-07:00
by anthony
Note IM saves and used the correct JPEG density setting.

Photoshop however does not, it saves and uses a density setting in one of its special profiles, and not the default JPEG settings. You will need to strip that profile from the image before photoshop will use the proper default JPEG density information.

Arrrggghhhh....... (do you have any hair left!)