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Re: convert jpg to png creates very large file

Posted: 2007-07-11T00:40:05-07:00
by anthony
You can not keep the same file size in PNG as you can in JPG. Jpeg is a very highly compressed (loosy compressed) image file format. PNG is an exact compression image format that will not loose information to make it compress better. As such a PNG image is always a lot bigger than a JPG image.

You can improve the compression of PNg by setting a specific quality level
-quality 92 is good for general cartton like images or diagrams, while 95 is good for photos. the 9 is the compression level, the second number is the data storage filter style.

See IM examples PNG format
http://www.imagemagick.org/Usage/formats/#png