Eliminate a background

[Guest]

I want to eliminate a solid black background on an image so the forground remains & can be superimposed over other images. I am new to Photoshop & need very specific instructions.

[jane-e]

Hi

Try Select > Select Subject

https://photoshoptrainingchannel.com/select-subject-in-photoshop/

followed by adding a layer mask

https://helpx.adobe.com/photoshop/using/masking-layers.html

Save in a format that supports transparency: psd, tiff, png.

Let us know how this goes.

~ Jane

[Peru Bob]

The magic eraser tool might work.  You may have to try different tolerance values.

Change similar pixels with the Magic Eraser tool

When you click in a layer with the Magic Eraser tool, the tool changes all similar pixels to transparent. If you’re working in a layer with locked transparency, the pixels change to the background color. If you click in the background, it is converted to a layer and all similar pixels change to transparent.

You can choose to erase contiguous pixels only or all similar pixels on the current layer.

Example of erasing similar pixels

• Select the Magic Eraser tool  .

• Do the following in the options bar:

  • Enter a tolerance value to define the range of colors that can be erased. A low tolerance erases pixels within a range of color values very similar to the pixel you click. A high tolerance extends the range of colors that will be erased.

  • Select Anti-aliased to smooth the edges of the area you erase.

  • Select Contiguous to erase only pixels contiguous to the one you click, or deselect to erase all similar pixels in the image.

  • Select Sample All Layers to sample the erased color using combined data from all visible layers.

  • Specify an opacity to define the strength of the erasure. An opacity of 100% erases pixels completely. A lower opacity erases pixels partially.

• Click in the part of the layer you want to erase.

  from here:

  https://helpx.adobe.com/photoshop/using/erasing-parts-image.html

[JJMack]

With that image it would be easy to select the Black  background with the Magic wand then expand the selection 1px. Either delete the black or create a layer mask using the selection to hide the black.  Then place in an image below. Or you could simply convert the background layer to a normal layer then place in an image under it and the set it blending mode to something in the lighten blend modes like screen to blend  the spiral into te lower image.

[Norman Sanders]

The first impulse was to use the Blend If command but some of the line edges were too soft to deliver a sharp edge.

I suggest Lab Color for creation of the mask. 

1.  Image Mode > Lab Color. In layers, click off the lock in the Background layer to eliminate it.

2 Choose Curves. (Note changes in Curves indicated with red arrows) Choose the Lightness channel in Curves and drag it down to create Lightness Copy

3. In Curves move the endpoints horizontally as shown to create sharp pure black and white image 

4.  In the Channels panel choose the symbol that Loads the Channel as a Selection

5. Return to the Layers panel and click on the Mask symbol. Done.

****

Last, return your original settings marked at the start with arrows

Return to RGB and add the image as a layer on any image. 

(EDITED for clarity)

[jane-e]

Lab wins again, @Norman Sanders !

~ Jane