Created attachment 11968 [details] PDF in question I got a segmentation fault when opening the attached PDF with mupdf-1.5-5.fc21.x86_64 . The PDF was created with img2pdf from JPEG 2000 (JP2) images produced by ImageMagick 6.7.7-10 (+ JasPer 1.900.1-14ubuntu3.2) from 4-bit grayscale TIFFs about 30 MPx big.
The PDF can be viewed with no crashes in the latest version of MuPDF. It still displays too dark, but that's a separate issue that has also been fixed.
Interesting. Thanks for testing and thanks for having previously performed whatever changed fixed this!