Legacy ImageMagick Discussions Archive

convert 370blue -thumbnail 370x370 -quality 100 result.jpg your input image 370blue is missing a suffix. This works fine for me on IM 6.9.2.4 Q16 Mac OSX convert 370blue.jpeg -thumbnail 370x370 -quality 100 result.jpg At 2015-09-24 you say: fmw42 wrote: It would be helpful to see your JPG result ...

Perhaps you should upgrade both IM and libjpeg. Also again, it would be interesting to see your resulting image that you say is changed? It's also failed with use imagick 6.9.2-3 ldd /usr/local/bin/convert |grep jpeg libjpeg.so.8 => /usr/lib/x86_64-linux-gnu/libjpeg.so.8 (0x00007fd0d99d9000 ...

It would be helpful to see your JPG result that you say has changed colors. JPG is a lossy compression and will always change pixel values. If you say the actual overall color has changed. That is different. It could be a bug in IM or that you are using an older version of libjpeg. I have tested ...

dlemstra wrote:The link of your original file seems to be missing?

origin: http://s3-us-west-2.amazonaws.com/qiniu-bs/370blue

Can you specify your operating system and the output from convert - version convert -version Version: ImageMagick 6.9.1-2 Q16 x86_64 2015-05-18 http://www.imagemagick.org Copyright: Copyright (C) 1999-2015 ImageMagick Studio LLC License: http://www.imagemagick.org/script/license.php Features: DPC ...

OS is Ubuntu 12.04 , imagick 6.9.1

origin: http://img.dajia365.com/8d7f61050f7075ec55eaff82a999da9f.jpg command : convert 8d7f61050f7075ec55eaff82a999da9f.jpg -thumbnail 370x370 -quality 100 result.jpg we found result.jpg colors was changed obviously. And we test others parameter value,there's not no change. convert ...

fmw42 wrote:There is a gray bar in the input image. Thus there will be a gray bar in the output image. Check your uploaded input image.

how to check and how to explain the bug

The input jpg seems to be corrupted. I get: Version: ImageMagick 6.9.1--6 Q16 x64 2015-06-20 http://www.imagemagick.org identify.exe: Premature end of JPEG file `56a8b0fc0ba55dde.jpg' @ warning/jpeg.c/JPEGWarningHandler/352. identify.exe: Corrupt JPEG data: premature end of data segment ...

fmw42 wrote:I see no issue. There is a gray bar at the bottom of your input image and it looks to be relatively in the same place in your output image.

I don't know why there is a gray bar at the bottom of my image after convert command.
Can you tell me why and how to resolve it?

Convert
origin: http://ac-qu3i5h38.clouddn.com/56a8b0fc0ba55dde.jpg
result: http://7jpt6r.com1.z0.glb.clouddn.com/result2.jpg (mark the different place)

command： convert origin -quality 75.0 -thumbnail 901x> +repage imgview2065838404.jpeg
I also don‘t know why

Watermark background : http://7xju4x.dl1.z0.glb.clouddn.com/front-female-ffffff.jpg watermark photo: http://7xju4x.dl1.z0.glb.clouddn.com/201577/149/1434219718659.jpg result: http://7jpt6r.com1.z0.glb.clouddn.com/result （color changed） command: convert imgs812375407.jpg -layers coalesce NULL: -g ...

1. The 90kb picture size is less than the larger ones because they are slightly (but imperceptibly) different. It is more compressible than the others. The 97kb and 104kb images have identical pixels. 2. As you observed, the 97kb is interlaced and the 104kb isn't. The order in which numbers appear ...

Quality is 100 in both images, but JPEG quality 100 is not lossless. The images are slightly (but imperceptibly) different. Compress them again with quality 92, they still look the same but are less than half the size. Compress them with -quality 75 and they still look the same but are reduced ...

Large : https://s3-us-west-2.amazonaws.com/qiniu-bs/97kb.jpeg
Small : https://s3-us-west-2.amazonaws.com/qiniu-bs/90kb.jpeg


Two images look like the same ,and quality is the same.
I want know how to reduce the large image size to 90kb,and width, height and quality no change