Legacy ImageMagick Discussions Archive

I am using command line ImageMagicK 6.7.0-Q16. When I do this: c:\ display myfile.jpg I got the following error: Magick: unable to open X server ''@error/display.c/DisplayImageCommand/428 [No such file or directory]. I was able to do "convert" and other stuff. I am using Windows XP. Please help ...

This seems to solve the problem: Open Regedit and Find HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\ Disable Paging Executive: XP pages data from RAM memory to the hard drive. We can stop this happening and keep more data in RAM, resulting in better ...

I have a scanned image (grayscale) and I want to find out the gamma correction value. I read from the ImageMagicK webpage that: "When processing an image, be aware of the colorspace. Many image processing algorithms assume a linear RGB colorspace. Although you may get satisfactory results processing ...

Hi Anthony,
I want the so called "raw" image pixel, ie. with the gamma effect removed.
Are you sure it is "-gamma 0.454545", not "-gamma 2.2"?
I am confused.
Could you please help?
Thanks...

oh yes "convert -limit memory 1 -limit map 1 image.jpg -gamma 0.454545 newimage.jpg" works after I freed some harddisk space. However "convert image.jpg -gamma 0.454545 newimage.jpg" still fails. Must I use the "-limit memory 1 -limit map 1" all the time? What is this option doing actually?

I tried "convert image.jpg -gamma 0.454545 newimage.jpg" but it gave me the following error: "Insufficient memory (case 4) newimage.jpg @ error/jpeg.c/JPEGErrorHandler/296" Then I tried this "convert -limit memory 1 -limit map 1 image.jpg -gamma 0.454545 newimage.jpg" but it gave me the following ...

I understand that JPG file (sRGB) are corrected for gamma (2.2 if I am not wrong).
How do I "de-gamma" it? i.e. remove the gamma correction, using command line option?

Bonzo wrote:I think 0 is success and 1 is fail.

But I do get return code of "4"..
Where can i find the source code for the command line tool, so that I could check all the return codes?

I am using LabVIEW command shell to execute the command line:
cmd /c convert -depth 8 -size 1500x13000 -density 800 gray:54_3.dat c:\Print_Quality_Project\VB_Test\54_3.jpg
and I got a return code of 1.
How do I find out what this return code means?

I want to crop large jpg file (800dpi, 29288 x14172pix => i.e 36.6" x17.7" ), to size 2800 x14172pix (i.e 3.5" x17.7"). What I did was: Firstly, use "stream" to avoid reading the entire image in order to reduce processing time: "stream -map i -storage-type char -extract 2800x14172+8000+0 54_800dpi ...

anthony wrote:Unless you tell it otherwise -- yes. 72dpi is the default.

Add a -density 800 to the convert command to fix.

Thanks anthony it works now!

The dat file is RAW image data. No data type information, no meta-data, not even the size of the image. Just raw data. In the convert you have specifed the size, and type (depth) of the data. You have addumes the numbers are in RGB order. But you have not specified the density, or any other image ...

I would like to change the resolution of a jpeg file, but keep the physical dimension the same, for example:
- original file: 800dpi, 4000x4000pix, 5"x5"
- converted file: 400dpi, 2000x2000, 5"x5"

How can I do this? Can someone pls show me how to do this using command line?

I want to crop large jpg file (800dpi, 29288 x14172pix => i.e 36.6" x17.7" ), to size 2800 x14172pix (i.e 3.5" x17.7"). What I did was: Firstly, use "stream" to avoid reading the entire image in order to reduce processing time: "stream -map i -storage-type char -extract 2800x14172+8000+0 54_800dpi ...

I am using ImageMagick-6.7.0-Q16 and I have a Test1.jpg file which is 28800x22400pixels (800dpi, grayscale), file size 63MB. I did a command line "convert Test1.jpg -crop 1000x1000+0+0 Test1_cropped.jpg" and it took me a long time. My computer is Pentium Core 2 2.66GHz and has 3GB RAM, running ...