Saved .mpo are not compatible with Fujifilm W3 cameras

[Franky4242]

What did you do?

When loading and then saving an .mpo image from fujifilm camera, the saved image breaks when viewed with a Fujifilm w3 camera (with autostereoscopic screen). There is a loading error displayed in the camera. 3D mpo loading in Pillow is ok it is possible to get left and right images but writing does not seem to be fully compatible.
My script to do this :

im = Image.open(mpo_input_filename)
im.save(mpo_output_filename, save_all=True)

What did you expect to happen?

saved image to open properly in Fujifilm camera viewer

What actually happened?

a loading error

What are your OS, Python and Pillow versions?

• OS: Windows 11
• Python: 3.11
• Pillow: 9.3

Image file is provided with a link as Github does not support upload of .mpo files : http://www.christian-roux.ch/mpo/63460_pbz98_3D_MPO_70pc.mpo
It is just an example as I have not found any .mpo working after a im.save(mpo_output_filename, save_all=True). I have tried many. NB : the program Stereo Photo Maker is able to generate valid .mpo for Fujifilm cameras.

[radarhere]

Hi. Without having access to a Fujifilm camera, the only way to verify a fix for this is to check with you, so this will involve trial and error.

My first attempt will be changing the MP Image Type from Undefined to Multi-frame Disparity, like your original image -
mpimagetype.mpo.zip. Does that work?

[Franky4242]

Hello Andrew Thanks for your quick response I am away from my pc for a couple of days. I will check when I am back. Kind regards Frank

[Franky4242]

Hello Andrew, It does not work. There is still a loading error. I've dug a little bit in the differences between the two files and there are many. I've written a little tool to parse JPEG files (I imagine you have much better tools yourself) Here are my findings : Original MPO file Pillow saved MPO file Image 1 Has APP1 EXIF No APP0 JFIF APP2 MPF has 5 fields MPF version present Other MPF fields seem less important Image 1 no APP1 APP0 JFIF APP2 MPF has 2 fields MPF version missing Image 2 Has APP2 MPF Image 2 Has no MPF I've put in red the most important differences. * Would it be possible to test a Pillow output with * No JFIF segment * An Exif segment * An MPF segment for the first image that contains the MPF Version field * Thanks in advance Frank

…

------------------------------ More detailed analysis first JPEG is the original file. Second JPEG is the output of PILLOW.

-----Start JPEG analyse : 414466 bytes ** SOI ** APP1 length= 7594 Exif in parse_identifier_segment new index 7596 ** EOI at 7626 new index 7627 ** APP2 length= 190 MPF in parse_identifier_segment MP_endian b'II*\x00' little offset 8 count 3 MPFVersionTagID 45056 b'\x00\xb0' MPFVersion type b'\x07\x00' count for MPFVersionTagID 4 MPF Version b'0100' NumberOfImageTagID 45057 b'\x01\xb0' numberOfImage type= b'\x04\x00' count for NumberOfImageTagID 1 nb_of_images = 2 MPEntryTagID 45058 b'\x02\xb0' MPEntry type b'\x07\x00' count for MPEntryTagID 32 image 1 : b"\x00\x002\x00\x00\x00R\x00\x00\x00\x02\x00\x02 \x80'" image 1 : attribute=3276800 size=5373952 offset=131072 dep1=8194 dep2=10112 image 2 : b'\x03\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x02\x00\x82+' image 2 : attribute=3 size=0 offset=131072 dep1=2 dep2=11138 end 3rd field field? b'\x03\x00\xad\t\x03\x00\x00\x00\x00\x00\x04\x00' MPIndivImageNumber type= b'\x04\x00' MPIndivImageNumber=1 BaseViewpointNumber type= b'\x04\x00' BaseViewpointNumber=1 ConvergenceAngle type= b'\n\x00' ConvergenceAngle=136 BaselineLength type= b'\x05\x00' BaselineLength=144 field? b'\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00M\x00\x00\x00\xe8\x03\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00' remaining size 50 new index 7817 ** EOI at 206694 new index 206695 ** EOI at 214436 new index 214437 ** APP2 length= 126 MPF in parse_identifier_segment MP_endian b'II*\x00' little offset 8 count 5 MPIndivImageNumber type= b'\x04\x00' MPIndivImageNumber=2 BaseViewpointNumber type= b'\x04\x00' BaseViewpointNumber=1 ConvergenceAngle type= b'\n\x00' ConvergenceAngle=74 BaselineLength type= b'\x05\x00' BaselineLength=82 field? b'\x00\x00\x00\x00\x16\x00\x00\x00\n\x00\x00\x00M\x00\x00\x00\xe8\x03\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00' remaining size 48 new index 214563 ** EOI at 414465 new index 414466

----------------------------------

-----Start JPEG analyse : 391369 bytes ** SOI ** APP0 length= 16 JFIF in parse_identifier_segment JFIF analysis b'\x01\x01\x00\x00\x01\x00\x01\x00\x00' new index 20 ** APP2 length= 76 MPF in parse_identifier_segment MP_endian b'II*\x00' little offset 8 count 2 NumberOfImageTagID 45057 b'\x01\xb0' numberOfImage type= b'\x04\x00' count for NumberOfImageTagID 1 nb_of_images = 2 MPEntryTagID 45058 b'\x02\xb0' MPEntry type b'\x07\x00' count for MPEntryTagID 32 image 1 : b'\x03\x00\x96\xfa\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00' image 1 : attribute=4204134403 size=2 offset=0 dep1=0 dep2=2 image 2 : b'\x02\x003\xfe\x02\x00z\xfa\x02\x00\x00\x00' image 2 : attribute=4264755202 size=4202299394 offset=2 dep1=0 dep2=0 end 2nd field new index 96 ** EOI at 195221 new index 195222 ** EOI at 391368 new index 391369

[Franky4242]

Hello Andrew, The MPVersion field seems to be mandatory in the specification : so it may be THE point that is making a load error in the camera ? ***@***.*** Kind regards Frank

[radarhere]

Here's my next attempt then

• One image just has the MPF Version, as you suggested
• Another has the MP Image Type as 'Multi-frame Disparity', the MPF Version and the MP Individual Image Number
• Another has the MP Image Type as 'Multi-frame Disparity', the MPF Version, the MP Individual Image Number and an EXIF block

attempt2.zip

[github-actions]

Closing this issue as no feedback has been received.

[radarhere]

#6735 has been merged, adding the MP Format Version. That may or may not resolve this issue, but without further feedback, there is no way to know.

[Franky4242]

Hello Andrew Sorry for not giving news All 3 attempt files still generate a load error. Plain jpeg from pillow do not generate errors but are not 3d. I am testing lots of different options to make it work but for the moment I have not been able to find any solution. When I look at the differences with 3d images that work, there is one thing I do not understand in these files: the image offset field that is given in the 1st image index of MPF segment does not seem to match the specification that I have found on CIPA website site. Do you have any idea about how the offset should be based linked to all segments size : jfif, exif (you use something like 28 + im1.size) Kind regards Frank