XnView Software

pam2pgm pf-269361_9.red.sp0.5.m1.16.a.pam -a -n -d
PAM->PGM against ALPHA (A=0) bkg w/ 8 threads in 0.0123 sec
WBHB: Wrote 72.304659MB (19 + 72304640) in 23.537ms, 3071.909 MB/s
pf-269361_9.red.sp0.5.m1.16.a.pam.a.pgm

PAM->PGM against NULL (N=1) bkg w/ 8 threads in 0.0146 sec
WBHB: Wrote 72 ...

I am looking at 4 byte/pixel, grayscale-alpha .PAM P7 files in XnView MP on Linux, latest.
The images seem to be interpreting the gray-opacity data as RGB(A?).
ImageMagick converts it correctly to PNG so the format seems to be correct.

pf-269361_9.red.sp0.5.m1.16.a.xnview.psycho.2k.jpg

The ...

Pierre,
The P7 files are made from a uint16_t channel from a camera raw file and another uint16_t OPACity channel, 0 -> invisible, 65535 -> fully opaque. 4 bytes per pixel. The Opacity is intended to make poorly exposed areas invisible while keeping the good parts. The Opacity is 16 bits to match ...

I am running 64 bit Linux and need a viewer for 4 byte per pixel grayscale with Alpha images. 64k grayscale with 64k alpha.

LodePNG works, but takes forever. By "works" I mean that it creates files which display correctly in Photoshop CS6, GIMP, Gwenview and ShowFOTO.

I hand rolled a PNG creator ...