After more investigation, I have results for both Blu-ray and DVD.
First of all I want to apologize for omitting very important detail: when I say "JPG", I mean "JPG with minimum compression, i.e. maximum quality".
Fred, of course JPG is lossy format, but high quality JPG is very difficult to distinguish from some non-compressed format.
So, this is the experiment: I made a five Blu-ray movies (default quality) with imported five different format of photo: original photo (5616x3159pix), BMP, JPG, PNG and TIF (all of them 1934x1088pix). For each movie, one of these photo has been placed on the same place in track. After that, I made the five more movies, but with parameters providing
maximum quality for Blu-ray movie.
Then, repeat the same procedure, but with BMP, JPG, PNG and TIF photos in 1024x576 pix., and made five movies for DVD
default quality, and five more for DVD
maximum quality.
Next, I captured the SAME FRAME from each of 20 movies, using PowerDVD (of course "capturing original video source size").
Results for Blu-ray, in order of frame quality:
1. BD max Quality from JPG - losing about 5%
2. BD max Quality from TIF - losing about 5%
3. BD max Quality from PNG - losing about 5%
4. BD max Quality from BMP - losing about 8%
5. BD max Quality from Original photo - losing about 13%
1. BD Default from JPG - losing about 8%
2. BD Default from TIF - losing about 10%
3. BD Default from PNG - losing about 10%
4. BD Default from BMP - losing about 13%
5. BD Default from Original photo - losing about 20%
Results for DVD, in order of frame quality:
1. DVD max Quality from JPG - losing about 35%
2. DVD max Quality from TIF - losing about 35%
3. DVD max Quality from PNG - losing about 35%
4. DVD max Quality from BMP - losing about 36%
5. DVD max Quality from Original photo - losing about 40%
1. DVD Default from JPG - losing about 35%
2. DVD Default from TIF - losing about 35%
3. DVD Default from PNG - losing about 35%
4. DVD Default from BMP - losing about 36%
5. DVD Default from Original photo - losing about 40%
Of course, percentage is subjective. Captured photos are big (about 6MB for BD, and 2MB ofr DVD), so I can not place them here. If anyone has some suggestion how to publish photos, I will do that.
Note: Size for prepared photos for DVD (1024x576) is disputable! Size has to be 720x576 with rectangle pixels, but I have had no time for that.
Conclusion:
For BD movie, the situation is not so bad, but DVD quality is REALLY awful!
The purpose of this investigation is not to make algorithm for "good quality static picture" (we all used that very rare in PD), but to find (more or less) exactly level of quality, which we can count on.
Anita, I absolutely support you opinion, and agree with every word you say! I buy car for driving, not to pick in its engine.