"An image from the DVD data itself, versus a display capture, has the benefit that it has not yet been 'enhanced' for viewing at several meters / many feet distance (normal sharpening settings often adds halos, and removes noise(?)). Otherwise, the number of pixels remains rather limited for the purpose of somewhat larger printed output (and the chance is that the pixels have some motion blur)."
Please explain what DVD data vs display capture means.
If you photograph the image as projected on a display, your image data will often be somewhat altered, based on the display settings. How the image data on the DVD is converted depends on the drivers that are used and the settings that are used.
For example, is the data displayed 1:1, i.e. 1-pixel input to 1-pixel output? Or is there anti-aliasing going on, or is the signal interlaced between two subsequent images, or is there edge contrast enhancement going on, or noise reduction, and what is the colorbalance or even colormanagement, what playback speed is used, and is that matched to the recorded number of frames/sec or is there temporal interpolation/filtering going on?
Also when reproduced from a display, are there any room reflections visible in the image?
So it's best to get a good quality DVD player application or editor where you have control over the various video driver aspects, and where you can capture single frames as direct as possible from the video pipeline, in a known colorspace.
My intention was to just get the DVD or Blu-ray disk, whichever is better and capture a portion of the display, looking for the best possible frame. Is there a better approach?
Besides the above considerations, look at the actual resolution of the data. Blu-Ray may have several to choose from because more data can be stored on a single disc, and maybe with different resolutions (full HD or 2K / 3K / 4K / and in the future 8K?). Can your display manage that resolution without scaling?
Thanks for the Topaz tip.
I have no intended commercial use so copyright is not a problem.
Personal use (e.g. a backup copy) is usually covered by the fair use doctrine, and a single frame is also, more often than not, fair use, within the other restrictions of one's jurisdiction.
The quality of a single frame is usually compromised by motion blur and/or depth of field limitations, so not losing more information during the upscaling, but possibly adding some useful resolution, can be very useful for such an enlargement needed for larger format print output. Topaz A.I. Gigapixel is a very promising application, in fact, currently it's the best I've tried.
Cheers,
Bart