I would like to prepare photo slideshow in 4k in program Picture2exe and later I would like to convert it to 4k video using Premiere Elements.
Remember, 4K is just a resolution, not the video compression or file extension. So, footage labeled 4K must be looked at for compressions and file extension as well as resolution.
Premiere Elements 12/12.1 has 4K project presets and export choices, Premiere Elements 11 does not. That begs the question if whether or not your specific 4K footage has any chances of importing into Premiere Elements 11 or any other version of the program. Have you tried it? But the important question is also...
What are the properties of the export from Picture2.exe? You need to know that before you can decide if it can be imported into any version of Premiere Elements.
Do you have Premiere Elements 11 at this time? If you do not, I would offer to look at your file in my Premiere Elements 11 on Windows 7 or 8.1 64 bit.
You might send the sample in a Dropbox link posted in this thread.
What is your plan - import your Picture2.exe footage (4K) into Premiere Elements and export that Timeline as burn to Blu-ray disc format on Blu-ray disc 1920 x 1080 @ 29.97 (or 25) interlaced frames per second?
Please review and consider and then let us know your details.