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Complete white image with 6.8.7
Posted: 2013-11-12T05:35:29-07:00
by sireeshala
Recently i have updated the image magick version to 6.8.7
i am using the bellow set of code to convert my image from jpg to tiff
Code: Select all
Image image;
image.read( "case.jpg" );
image.magick("TIFF");
image.compressType(Group4Compression);
image.type(BilevelType);
image.write("case_1.tiff");
I am getting a complete white image .
The same image used to work fine with 6.8.2 version .Are there any changes particular to this issue?
the image is at
https://www.dropbox.com/s/0sjy8uvc07f1yww/case.jpg
Re: Complete white image with 6.8.7
Posted: 2013-11-12T11:04:08-07:00
by fmw42
I get the same using IM 6.8.7.5 Q16 Mac OSX command line
Code: Select all
convert case.jpg -compress group4 -type bilevel tmp.tif
or
Code: Select all
convert case.jpg -type bilevel tmp.tif
But this works fine
Code: Select all
convert case.jpg -threshold 50% -compress group4 tmp.tif
Re: Complete white image with 6.8.7
Posted: 2013-11-18T22:09:11-07:00
by sireeshala
But its worked fine with out adding threshold value in 6.8.2
is this introduced in latest version ?
is there any specific criteria for an image to add the threshold value?
Re: Complete white image with 6.8.7
Posted: 2013-11-18T23:23:53-07:00
by fmw42
I suspect there was a bug introduced somewhere between these versions.
Re: Complete white image with 6.8.7
Posted: 2013-11-19T01:38:11-07:00
by sireeshala
What is the latest version of imageMagick?
I am using 6.8.7 dowloaded from
http://www.imagemagick.org/script/insta ... hp#windows ImageMagick-windows.zip
is there any version available other than this?
Re: Complete white image with 6.8.7
Posted: 2013-11-19T11:25:38-07:00
by fmw42
IM 6.8.7.6
see
http://www.imagemagick.org/script/binary-releases.php
convert -version
should tell you exactly what version you have
Re: Complete white image with 6.8.7
Posted: 2013-11-19T14:05:18-07:00
by dlemstra
I just tried the latest beta and this produces a white image for me on windows.
Re: Complete white image with 6.8.7
Posted: 2013-11-19T15:04:08-07:00
by fmw42
convert case.jpg -compress group4 -type bilevel tmp.tif
produces a white image for me, too, on 6.8.7.6 Q16 Mac OSX
Re: Complete white image with 6.8.7
Posted: 2013-11-19T21:20:10-07:00
by sireeshala
convert case.jpg -compress group4 -type bilevel tmp.tif
But this works fine on windows mechine with version 6.8.2-4.
Only the latest versions giving the white image.
Re: Complete white image with 6.8.7
Posted: 2013-11-20T02:45:49-07:00
by sireeshala
Is this a Bug or a new property "threshold" introduced to the latest versions?
can any one confirm on this ?
Re: Complete white image with 6.8.7
Posted: 2013-11-20T10:58:58-07:00
by fmw42
-threshold is just a different way to get a binary image result. The threshold will change where the spit is between white an black in the image. It is not a requirement. The problem you are having is likely a bug. I only added -threshold to give you an alternate until this gets fixed.
Re: Complete white image with 6.8.7
Posted: 2013-11-20T11:30:44-07:00
by snibgo
Group4 is a method for compressing images that contain only black and white. If the image contains other colours, IM needs to reduce it first. I don't suppose this reduction is well-defined, so is always subject to variations in methods used by IM to reduce colours. So it would seem better to always do the explicit reduction first.
Re: Complete white image with 6.8.7
Posted: 2013-11-20T21:51:11-07:00
by sireeshala
I only added -threshold to give you an alternate until this gets fixed.
Is there any estimated dates to get that fixed ?
Basically we are using this from a bat file so we cant particulary change the the command for a single image every time .
Re: Complete white image with 6.8.7
Posted: 2013-11-21T08:27:38-07:00
by magick
Try
- convert case.jpg -normalize -dither none -type bilevel -compress group4 tmp.tif
We will take a closer look at the bilevel algorithm, maybe we can get it to work without normalizing.
Re: Complete white image with 6.8.7
Posted: 2013-11-28T04:29:55-07:00
by sireeshala
But How its worked with 6.8.2-4 .
And how much time it will take to get an update on this issue
