File size increase With resize parameter

[David Bethel]

Greetings,

6.8.8-Q16

I'm a newbie to ImageMagick, so I have some really basic needs

I can successfully create an animated gif using the following : ( 100 bmp frames @ 1024x768 )

Code: Select all

onvert.exe -resize 512x384 -delay 33 -brightness-contrast 15 -type optimize -dispose none c:/bmp/*.bmp -loop 0  c:/acad/1000.gif

To my surprise, the file size increased with the use of -rsize and / or -type . I would have thought there would have been a substantial decrease. Am I missing some thing?

Approx 1.2 MB to 1.5 MB

Thanks ! -David

[fmw42]

You have a different colormap for each frame. Try using a common colormap. See -remap http://www.imagemagick.org/Usage/quantize/#remap but use +dither or -dither none.

see also
http://www.imagemagick.org/Usage/anim_opt/#colortables
http://www.imagemagick.org/Usage/video/#gif

[David Bethel]

Thank you !

The +map and +remap reduced the size to 1MB.

The remap to colortable.gif reduced it to 500KB. The brightness parameter became unacceptable, but that is not a big deal ( black turned into hunter green )

I will reread the links that you a few time as the terms and details are quite new to me.

-David

[fmw42]

Make sure your colormap image contains black.

[David Bethel]

As my images are cartoonish, I used the colortable.gif from the link that you provided. I will flood fill the black dot with pure black #000000 just to be sure.

Thanks! -David

You should perhaps create a colortable from your input images. Perhaps average all your input images (or many of them over the sequence), reduce to 256 colors and extract the colortable. Then choose how many colors (<=256) you want to use and create an image from those colors, by appending

convert xc:color1 xc:color2 ... xc:color256 -append colortable.gif