Nevermind. I upgraded my imagemagick to the latest version (6.4.0-10) and I'm getting the same results.
Thanks for the help, -- Joel On Fri, Apr 25, 2008 at 12:50 PM, Joel Poloney <[EMAIL PROTECTED]> wrote: > I tried this myself and I couldn't get the file sizes that you were > getting. Here's a list of the commands I was running: > > wget http://joel.poloney.com/source.png > convert -resize 426x320 -dither -colors 256 -depth 8 source.png resized.png > pngcrush source.png crushed.png > > Here are my file sizes: > > crushed.png - 76,593 > resized.png - 142,057 > source.png - 87,833 > > Any ideas? > > -- Joel > > > > On Fri, Apr 25, 2008 at 9:30 AM, Ross Presser <[EMAIL PROTECTED]> wrote: > >> 1. Your source image is a 256-color palette image. If you resize any >> image, by default the output will be in truecolor aka 24 bit color aka 8 >> bits per pixel. You must quantize the image down to 256 colors. This >> commandline resizes and quantizes, giving an output of 52,209 bytes: >> >> convert -resize 426x320 -dither -colors 256 -depth 8 source.png >> resized.png >> >> 2. For even more compression, you can turn to pngcrush, not part of >> imagemgick but a separate package. pngcrush applied to resize.png gave me an >> output of 49,905 bytes. >> >> 3. Both convert and pngcrush will preserve the transparency in this case. >> >> >> On Fri, Apr 25, 2008 at 3:31 AM, Joel Poloney <[EMAIL PROTECTED]> wrote: >> >>> I've been banging my head against this all night and can't come up with >>> any >>> solution. I'm trying to take a PNG image, resize it, and compress it (if >>> I >>> can). The PNG image I'm working with has transparency. You can find it >>> here: >>> http://joel.poloney.com/source.png. I have imagemagick version 6.2.4. >>> >>> The source png is 85kb. If I run the command "convert -compress JPEG >>> -quality 80 source.png output.png", the output.png is about 118kb. >>> Obviously, that didn't work. Say I want to resize this image down before >>> I >>> compress it. The original size of this is 600x450. If I run the command >>> "convert -resize 426x320 source.png resized.png", the resized.png is >>> about >>> 150kb. Why is my image smaller pixel-wise and bigger file-size wise? >>> >>> I then began experimenting with image masks. I figured, if I could >>> extract >>> out the alpha channel into a 8-bit mask.png ("convert source.png -channel >>> matte -negate -separate -depth 8 -type Grayscale mask.png"). I then >>> converted the png to a jpeg and compressed the jpeg. I finally composed >>> the >>> two back together with the "-compose Copy_Opacity" option, and it >>> works... >>> but the file size is enormous. >>> >>> If I use the original source png in Flash CS3 and create a simple movie >>> with >>> 1 frame (the source.png), and export it (with a jpeg compression of 80), >>> the >>> resulting swf is 37.1kb. They're doing some kind of compression and I >>> can't >>> figure out what it is and why it's not working with imagemagick. >>> >>> Any suggestions? >>> >>> Thanks, >>> >>> -- Joel >>> _______________________________________________ >>> Magick-users mailing list >>> [email protected] >>> http://studio.imagemagick.org/mailman/listinfo/magick-users >>> >> >> Greased Lightbox <http://shiftingpixel.com/lightbox/> →←+-↻ >> >> Loading image >> >> Click anywhere to cancel >> >> Image unavailable >> >> >
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