1 2 3 4
- Image 1 is the original main file as displayed by ImageMagick
display. It is showing up as a negative, but shouldn't be. When displayed using other tools, it's normal.
- Image 2 is Image 4 appended to Image 1 using `convert main.jpg footer.jpg -append output.jpg. The main part is still negative, but the footer is normal
- Image 3 is the same file as Image 2, but as displayed by Windows Preview (it's the same in anything but IM
display). The main image is normal, but the footer is negative.
- Image 4 is the footer file which displays normally by itself in all utilities.
I have tried doing:
convert main.jpg -negate footer.jpg -append -negate output.jpg
but that makes the footer almost completely black (but it displays correctly in IM
display!). It also has the disadvantage that it doesn't do the right thing for images that are correct to start with.
The problem is that I have a large batch of files to process and some of them don't exhibit this problem. Using
identify -verbose, I've found that some of the problematic files seem to be more likely to have "Resolution" that's equal or near the Geometry dimensions of the image. Images that have "Resolution" that's higher than or significantly lower than the Geometry seem to be less likely to exhibit this problem.
The main images are all 350x350 pixels and the footer is 350x60.
Other differences (from
identify -verbose) that may be significant:
Image: NORMAL.jpg Image: NEGATIVE.jpg Format: JPEG Format: JPEG Class: DirectClass Class: DirectClass Geometry: 350x350+0+0 Geometry: 350x350+0+0 Resolution: 100x100 Resolution: 338.66x338.66 Print size: 3.5x3.5 Print size: 1.03348x1.03348 Units: Undefined Units: PixelsPerInch Type: TrueColor Type: ColorSeparation Endianess: Undefined Endianess: Undefined Colorspace: RGB Colorspace: CMYK Depth: 8-bit Depth: 8-bit Channel depth: Channel depth: red: 8-bit cyan: 8-bit green: 8-bit magenta: 8-bit blue: 8-bit yellow: 8-bit black: 8-bit
I've tried this using IM 6.5.1-0 and 6.6.8-3 in Linux and 6.5.2-5 in Windows.
How can I reliably diagnose what's causing this and correct it automatically? How can I append these images in a batch without having to do a lot of manual intervention?
I apologize for the small snippets, but these are copyrighted images.