I am searching for a native tool on MacOS that can increase the resolution of a group of image files whose aspect ratios (file width versus height) vary widely. There are numerous files so I don't wish to do this manually. Someone suggested the sips command with the resampling option but it appears this requires you to input a desired width and height. As found on the sips man page.
Is there some other UNIX command that can do what I wish? All I need to do (I think) is increase the number of pixels so that when the image is blown up then it appears smooth and not grainy or 'washed-out'.
thanks so much for your suggestions.
postscript - These image files are used in an iOS program and the problem appears on the large screen sizes of the ipad pro third generation.
Thanks for the suggestion, however, after investigating that software more carefully it appears that it requires Xquartz/X11 and my understanding is that software is obsolete and doesn't play well with the current version of MacOS. It's a pity because otherwise it appears to be exactly what I need.
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=> Pouring imagemagick-7.0.8-59.mojave.bottle.tar.gz
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