delete background of selection

[lettergothic]

Because of black in an image abutting the black background—which I want to delete, I can't use the wand to select the black background. In situations where I can use the wand, however, I select the background, hit delete, black disappears and I've got the desired checkerboard.  However, when I select the object w/the magnetic lasso, invert the selection and hit delete to get rid of the b'ground—nothing happens; it doesn't delete the black b'grnd. How come it doesn't delete the b'ground like the wand selection? How do I delete the b'ground with the lasso selection?

Thanks again, as always.

lettergothic   

[lettergothic]

Errka Petti, thanks for responding.

I'm sorry but, unfortunately, I'm afraid that I don't understand your response . . .

Could you please explain in more detail.

thanks,

lettergothic

[Callum]

Hi Lettergothic,

It should work if you have the layer rasterised and selected. Please could you provide a screen recording of you using the Lasso tool?

Thanks

Callum

[lettergothic]

Callum, thanks very much for responding. I appreciate it.

"...have the layer rasterised" — The image is a photograph on a black ground. It's already a bitmap when I open it in APhoto, no? One rasterizes vector images, no? There's only one layer.
"...provide a screen recording" — I don't know how to do that but I do know how to use the "wand" and the "lasso". I've attached the image in question—an open book on a black bg. I want to eliminate the bg. so I just have the irregular shape of the book. I've successfully done this on about 6 of them just like this one. I can't (don't know how to) use the wand on this one because of the B+W image (bottom center) abutting the blk. bg. The wand selection enters the image and I can't seem to get the "wand-subtract" setting to eliminate the inadvertent selection of portions of the image. With the magnetic lasso, I can switch to manual mode right before the problem area, trace the edge of the page across the problem area manually (sort of  :-/ ) and them resume "magnetic" right after the image. When I close the selection, I get the marching ants around the book spread. I choose "invert selection" to select the blk. bg. I hit "delete" (as I do, successfully, with the wand) and nothing happens—the bg is not deleted. How do I get the bg. to delete? Why is this different that the wand "delete"? Is there a technique with the wand—that I'm unaware of—that I could use to solve this? In the end, of course, I just want a fast, non-manual way of outlining the spread (pretty well) and ditching the bg. I can do it, except in this case, because the wand can't distinguish the blk. in the image from the blk. bg.

Thanks very much. I really appreciate your help.