How to remove black borders from picture?

The image you have is 1920 x 1080.

The part you want is 1920 x 800.

800 is 74% of 1080.

So select the whole picture then goto Transform Selection and pick 74% for the Height.

Pick Crop Selection and you will get a perfect crop every-time.

What I would do is either crop or convert the image to a smart layer and then choose the magic wand tool and select the black areas. Then hit the delete key and use the checkered pattern (see through) as the fill.

you can also use the Crop tool (C key on your keyboard), select the area you want to remain and Apply by pressing the Apply button (the checkmark icon) on the options bar at top of screen or just press Enter until it is cropped.

You may be able to use the Image - Trim feature, though it requires exact pixel color matches, which may not be true with lossy compression (e.g., JPEGs).

Another way is to use the Magic Wand Selection Tool with some tolerance (e.g., 24), select the borders, invert the selection, then use Image - Crop.  It will cut off all fully selected rectangles of pixels.

Watch your copyright issues if modifying copyrighted works

-Noel