Legacy ImageMagick Discussions Archive

So ,i think we need add alpha on not off Have you tried it? For me, IM v6.9.0-0, "-alpha on" does not work. "-alpha off" does work. 1、why this is success convert bigger.png -thumbnail 450x -colors 256 -type Palette a.png //notice :the same image,only thumbnail different It works...

I think the problem is that the total number of opaque colours plus the number of (semi-)transparent pixels must be <= 256. "-alpha off" will ensure there are no (semi-)transparent pixels. convert bigger.png -thumbnail 500x -alpha off -colors 256 -type palette a.png 1、 why this is success...

For animated GIFs, I suggest you read the documentation. See "animation" in http://www.imagemagick.org/Usage/ This works fine: convert 3000.gif -layers coalesce -resize 200x -layers optimize t.gif Sir，I need your help http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=27203

Image: http://s3-us-west-2.amazonaws.com/qiniu-bs/bigger.png //clolormodel = palette 256 Command : convert bigger.png -thumbnail 500x -colors 256 -type Palette a.png //fail convert bigger.png -thumbnail 450x -colors 256 -type Palette a.png //success debug info: fail: 2015-03-16T18:09:00+08:00 0:00.1...

See http://www.imagemagick.org/script/architecture.php Q8 uses half the memory of Q16. Image ：http://s3-us-west-2.amazonaws.com/qiniu-bs/2.png Type ：Palette2 If use command: convert 2.png -thumbnail 400x b.png //size bigger than origin But use command like you : convert 2.png -thumbnail 400x -color...

See http://www.imagemagick.org/script/architecture.php Q8 uses half the memory of Q16. Image ：http://s3-us-west-2.amazonaws.com/qiniu-bs/2.png Type ：Palette2 If use command: convert 2.png -thumbnail 400x b.png //size bigger than origin But use command like you : convert 2.png -thumbnail 400x -color...

What version of IM are you using? With v6.9.0-0 I get: f:\web\im>%IM%identify bigger.png bigger.png PNG 720x300 720x300+0+0 8-bit sRGB 256c 56.5KB 0.000u 0:00.000 f:\web\im>%IM%convert bigger.png -thumbnail 600x b.png f:\web\im>%IM%identify b.png b.png PNG 600x250 600x250+0+0 8-bit sRGB 124KB 0.000...

As upthread: "The "256c" label has gone. The input had only 256 colours, but interpolated resizing has increased the number of colours, so the output isn't palleted." So use "-colors 255 -type Palette" again. Do you know the rules http://www.imagemagick.org/discourse-s...

glennrp wrote:

snibgo wrote:Pngcrush may be useful.

Pngcrush won't help much if there are more than 256 colors (including the background color) present.

pngquant is a good tool,but I want use imagemagick

snibgo wrote:Pngcrush may be useful.

Your means is imagemagick can't resolve?

You can use "-quality" with webp to trade-off quality against size. For example: f:\web\im>%IM%convert upload.webp -thumbnail 200x -quality 10 x.webp upload.webp is 5400 bytes. x.webp is 2034 bytes. Sir, the same question like bmp Image：http://s3-us-west-2.amazonaws.com/qiniu-bs/bigger.pn...

See http://www.imagemagick.org/script/architecture.php Q8 uses half the memory of Q16. Thank you very much，can you help me this issue http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=27148 Sir,another quesstion :webp image become bigger too after thumbnail Image:http://7te8ta.com...

snibgo wrote:See http://www.imagemagick.org/script/architecture.php

Q8 uses half the memory of Q16.

Thank you very much，can you help me this issue viewtopic.php?f=3&t=27148

Hi：
There is a gif which imagemagick can't convert it.
Image: http://s3-us-west-2.amazonaws.com/qiniu-bs/3000.gif

I want to thumbnail it
Command : convert 3000.gif -thumbnail 200x +repage result.gif

Can you try it

What version of IM are you using? With v6.9.0-0 I get: f:\web\im>%IM%identify bigger.png bigger.png PNG 720x300 720x300+0+0 8-bit sRGB 256c 56.5KB 0.000u 0:00.000 f:\web\im>%IM%convert bigger.png -thumbnail 600x b.png f:\web\im>%IM%identify b.png b.png PNG 600x250 600x250+0+0 8-bit sRGB 124KB 0.000...