Filtering long lists of images
I suspect that performance with 15k images will be bad no matter what you do. You might want to rethink your UI.

If you want to know which is the fastest solution you will have to measure them. Though I would guess the second is faster. You could test a direct document.querySelector though jQuery should be passing the query through pretty much as is. The one suggestion I would make is instead of interpolating your image_id each time give all of the images a class and use a class selector.

As to your last question, I don't know of anyway to do it using pure css and there would probably be little advantage anyway.