EXR conversion from TIF oddness

[magick]

As mentioned the problem you reported is fixed in ImageMagick 6.7.1-0 Beta. We'll release 6.7.1 within a few days.

With 6.7.1 we get:

• -> convert -colorspace sRGB testchart.tif -colorspace sRGB testchart.exr
  -> compare -metric rmse testchart.exr testchart.tif null:
  6.54481 (9.98674e-05)

Yes, we know GM returns 0 error, but that's because GM does not support the EXR image format. You are instead getting TIFF. EXR has 16-bit floating point so some error is expected. If IM supported 32-bit EXR, the error would be 0.

Let's try EXR without any colorspace option:

• -> convert testchart.tif testchart.exr
  -> compare -metric rmse testchart.exr testchart.tif null:
  6.54481 (9.98674e-05)

Now let's try with TIFF:

• -> convert -colorspace sRGB testchart.tif -colorspace sRGB testchart-1.tif
  -> compare -metric rmse testchart-1.tif testchart.tif null:
  0 (0)

TIFF is a lossless format so we get 0 error as expected for the 1:1 roundtrip.

[troy_s]

Yes, we know GM returns 0 error, but that's because GM does not support the EXR image format. You are instead getting TIFF.

Wow. My mind is blown.

My sincerest apologies Magick.

I cannot believe that GM doesn't issue a warning or output when you attempt to convert to an unsupported image format. Ridiculous.

Looking forward to the patch. I tried trunk, but had similar issues.