Downsample JPEG to 72x72

[wingo]

Hello Everyone,

I am hoping someone might be able to help me out. I am trying to use ImageMagick to convert an image that is 1400x900 with a resolution of 254x254. i am trying to get it to a size of 1100x600 with a resolution of 72x72. I have tried to use -resize -resample with the quality arg. I don't seem to be able to get it done. I have tried my suggestions from the web, but none so far have worked out. Anyone have an command line that might work for this. Running on Mountain Lion.

Thanks Bob.

[snibgo]

This should do the job:

Code: Select all

convert in.jpg -resize 1100x600! -density 72 out.jpg

[wingo]

Thanks, that did the trick for the resolution! Not sure how I missed that one.

[henrywho]

Depending on the image content, you may also want to refer to the resize algorithms and the gamma issues mentioned in:

http://www.imagemagick.org/Usage/filter ... downsample

For example:

Code: Select all

convert in.jpg -colorspace RGB -filter LanczosRadius           -distort Resize 1100x600! -density 72 -colorspace sRGB out.jpg
convert in.jpg -colorspace RGB -filter LanczosSharp            -distort Resize 1100x600! -density 72 -colorspace sRGB out.jpg
convert in.jpg -colorspace RGB -define filter:window=Quadratic -distort Resize 1100x600! -density 72 -colorspace sRGB out.jpg