mono format returns blank image when compile from source

[john_thur]

When installing from pre-compiled distribution it works. When compiling myself it doesn't. Other formats JPG, GIF work fine.

Same machine. Want to modify, but tested before I did.

Is there a new no-defaulted option on converting to the mono format. The converted image is a b/w JPG.

The follow test is always returns same result. All pixels are processed.
From mono.c WriteMONOImage

Code: Select all

      if (image->endian == LSBEndian)
        {
          if (PixelIntensity(p) < (QuantumRange/2.0))
            byte|=0x80;
        }
      else
        if (PixelIntensity(p) >= (QuantumRange/2.0))
          byte|=0x80;

[magick]

We can reproduce the problem you posted and already have a fix. Look for a point release of ImageMagick with the fix within a few days.

[john_thur]

Thanks the new post fix it. I am currious what was done to fix. I have copied mono.c to create a new modual, suffers same problem and mono used to.