Possible bug reading JP2 as grayscale when should be in color about openjpeg HOT 3 CLOSED

The issue is that the value of the EnumCS of the colr box is 17=GreyScale. It should rather be 16=sRGB

    <JP2Box name="colr" box_offset="66" box_length="15" data_offset="74" data_length="7">
      <BinaryContent>01000000000011</BinaryContent>
      <DecodedContent>
        <Field name="METH" type="uint8" description="Enumerated Colourspace">1</Field>
        <Field name="PREC" type="uint8">0</Field>
        <Field name="APPROX" type="uint8">0</Field>
        <Field name="EnumCS" type="uint32" description="greyscale">17</Field>
      </DecodedContent>
    </JP2Box>

from openjpeg.

by the way recent versions of Kakadu also complain about that file: "Looks like the file contains an illegal channel definitions (cdef) box; trying to fix the problem so that content can still be rendered."

from openjpeg.

Agreed. It likely needs to be coded as RGB not grayscale. Also the 4th channel is coded as alpha and I think it might be an IR channel. The files are likely miscoded or they were created under an earlier definition of the format, though I suspect the former is the issue.

from openjpeg.