There are a few ways to make a black background transparent in Photoshop. One way is to use the transparency filter. Another way is to use the “layers” tool and create a new layer beneath the original black layer. Then, use the “mask” tool to select just one of the pixels in the black layer and mask it out so that it is transparent. Finally, use the “overlay” tool to add a white color to the transparent pixels.
There are a few ways to remove black backgrounds from PNGs. One way is to use a PNG editor such as Adobe Photoshop or Illustrator. Another way is to use a program such as Picasa or Google Earth to take a picture of the background and then use that program to create a PNG with the background removed.