I’ve noticed that photos in slideshows produced with FotoMagico 3.8.2 are lighter (over-exposed) than the original photos. The output being 720p, I would expect lower resolution photos but not lighter ones. Is there a setting I’ve missed to correct this issue? I did a iMovie 11 slideshow with the same photo and didn’t see this characteristic. Attached is a pdf file to demonstrate the problem.
Thanks,
Ed
Bump
I’m sorry, but I cant open your attached file.
But I know there could be a slight gamma-shift when exporting photos to a videofile. I’dont know if thats a problem in fotomagico, I know it from other applications. Have you tried different output-file-types (codecs)?
It does appear to be a gamma-shift. I imported a single frame from the output of FotoMagico into Photoshop. In Photoshop, the gamma of that frame can be adjusted to match the original jpg photo. The problem appears in Web/iPod/iPhone/iPad/AppleTV/HD movies. The Stand-Alone player works fine. I didn’t test any of the other formats.
I spent some time to quantify the problem rather than relying on an expressed opinion of an observed difference. It appears that I was not the first one to notice this problem… http://forum.boinx.com/discussion/156/washed-out-colors-in-video. The purpose of this study is not to determine the best video compression or compression options to use but to determine if there is a difference between iMovie and FotoMagico using the same H.264 video compression with the same options.
Doing a Google search revealed that people have been dealing with poor quality videos generated with other apps using H.264 and were recommending other video compressors like X.264. Apple uses H.264 in iMovie. Now the work begins.
The plan was to make a short video composed of one photo and one short video clip on iMovie and FotoMagico and measure the results with Photoshop. This would determine if there was a gamma shift, color shift or less color saturation in the compressed test video.
Found a color test photo on the Internet with a grayscale and a few colors. Converted the gif file into a jpg file http://dl.dropbox.com/u/7829364/ColorTest.jpg and measured the grayscale, red, green and blue colors for a baseline. Used that photo and produced a short 2 second Quicktime video clip http://dl.dropbox.com/u/7829364/VideoClip.mov with iMovie and measured one of the video frames of the video for a baseline. Photoshop has the capability of importing a video and viewing/measuring each video frame. The photo and video clip were used to make the iMovie and FotoMagico test videos. In each of the test videos, a video frame of the photo and a video frame of the video clip were measured. The results of these tests are contained in file http://dl.dropbox.com/u/7829364/H264TestResults.pdf. For RGB background, read http://en.wikipedia.org/wiki/RGB_color_model.
The iMovie Quicktime test video settings for http://dl.dropbox.com/u/7829364/iMvideo.mov were:
Stage Size: 720P
Share > Export Using QuickTime > Export: Movie to QuickTime Movie Options
Video:
–Compression: H.264
–Quality: high
–Encoding mode: multi-pass
–Dimensions: 1280x720
Sound: (not selected)
Prepare for Internet Streaming:
–Fast Start
The FotoMagico HD Movie test video settings for http://dl.dropbox.com/u/7829364/FMvideoHD.mov were:
Stage Size: 720P
File > Share > HD Movie > Size: 720P; Framerate: 30fps
The FotoMagico Quicktime Movie test video settings for http://dl.dropbox.com/u/7829364/FMvideoQT.mov were:
Stage Size: 720P
File > Share > QuickTime Movie >
–Settings: Custom
–Encoded Size 1280x720
–Framerate; 30fps
Compression Customize >
Video:
–Compression: H.264
–Quality: high
–Encoding mode: multi-pass
–Dimensions: 1280x720
Sound:
–Format: MPEG-4 Audio
–Sound rate 44.1 kHz
–Sample size: 16
–Channels: 2
Prepare for Internet Streaming:
–Fast Start
So the bottom line…
iMovie does generate a better quality video (less gamma shift) than FotoMagico with the QuickTime Movie option using the same H.264 video compression. Why? FotoMagico with the HD Movie option produces a poorer quality video (reduced green saturation) than the FotoMagico QuickTime Movie option even though the meta data of the output file (according to the Finder) appears to be the same. Why? Viewing these test videos doesn’t show the real problem of poor highlights, shadows, details, clarity and color saturation of actual photos that I’ve observed and as mentioned in the above Boinx forum. The output quality from iMovie is acceptable. Why can’t FotoMagico produce the same quality video using the same video compression?
The purpose of this analysis is not to bash FotoMagico but to improve the quality and understanding of an already great product. Thanks for what you have done and what you will do in the future.
Ed
It’s a problem with color profiles. I would like a solution to this too.
When running a slideshow through the app or the Standalone Player, FotoMagico uses OS X display functions which recognise the image profile and convert the colors to the right numbers for the monitor’s profile. This works great, except that prior to Lion OS X seems to treat untagged images as if they should be sent un-modified (rather than assuming them to be sRGB, which is what Lion does). Preview has this same quirk BTW.
However, when exporting into any of the movie formats, something is going wrong when playing those movies back in Quicktime Player. The “gamma” effect is the most obvious, but again the details depend on the source image’s profile.
When examining an “HD Movie” in Finder I can see (via Get Info) that it has the Color profile “HD (1-1-1)”. Playing around in Automator I can assign different profiles (“SD”, “PAL”, or “HD”) which do affect the colors slightly on playback but don’t fix the problem.
Somewhere between FotoMagico converting the colors to the movie color profile (it does do this, right???) and Quicktime Player converting these to the display’s profile, something’s going wrong.
The Apple h.264 encoder tends to desaturate and overbrighten exports a little. we cant really compensate for that, as the color and brightness shift is non-deterministic. If you use the QuickTime Export and use for example ProRes422 HQ as the codec, colors should be fine.
Thanks for the advice of using the ProRes422 HQ codec but it appears that the only way to get this codec is with FinalCutPro which I don’t have. The question I would like answered is… Why does iMovie generate a better quality video (less gamma shift) than FotoMagico with the same H.264 codec? Do you use the same resident (on the Mac) H.264 codec that iMovie is using or is it some equivalent codec within your code?
