Creating a transparent background.

[Art4ArtSake]

I have scanned a handwritten formulae. I want to make the background transparent so that I can overlay the formulae to appear on top of a photograph in a new layer. Is there any way I make the background transparent?

 

[IamSam]

Just don't add a white underlying layer.



Follow Rich's steps in the thread below.

removing lines and bleed through on writing paper?

seem to be having another senior moment ;-( used to do this all the time, but haven't done anything like it for years... there's also some that are simply b&w, with the same problem. this is for a friends daughters 50th birthday, and though i think they have more 'character' as they are...

www.photoshopgurus.com

 

[Art4ArtSake]

Thank you for your reply Sam. Sorry to be tedious. I scanned the image written in blue biro on white paper (hence white background). From this scanned image, how do I now remove the white paper (background) behind the blue biro formulae? How did you create the transparent background in you reply. Thank you in anticipation.

 

[IamSam]

I scanned the image written in blue biro on white paper (hence white background). From this scanned image, how do I now remove the white paper (background) behind the blue biro formulae?

Yes, I understood this from your original post and I answered it for you.

I did this following Rich's suggestion from the thread I linked you with.

Just use the "Blend if" option on the "This Layer" in a layer style under blending options. Split the slider by holding the opt/alt key and clicking and dragging the split slider to the left.

 

[IamSam]

Set your foreground color to Blue Brio (#0084B6)
Once you have the white BG removed using the blend if option, just make two copies (Cmd/Cntrl + J x 2). Deactivate/turn off the original layer. Hold the shift key and click/highlight on both of the copies and then hit Cmd/Cntrl + E to merge. Name this merged layer "Main layer" and then deactivate/turn off the layer. Create a new layer. Hold the Cmd/Cntrl key and click on the "Main Layer" thumbnail to create a selection. Fill the selection with the forground color (Opt/Alt + delete/backspace).

Now you will have a Blue brio copy with a transparent BG.

 

[thebestcpu]

I would like to add a step that may have been missing from prior examples.
For the Belend If sliders to work and create transparency, the Layer that you have scanned cannot be a Background (locked) Layer as that prevents any transparency.
Once you convert the background Layer to a normal Layer you can create transparency with the Blend If controls.

Also note, I think you would get a better result with a higher resolution scan (up upsizing in Photoshop) by about 4X and the using a Curves Adjustment Layer to increase the contrast in the image before applying the Blend If sliders
Hope the incremental information helps if you have not already solved the problem.
John Wheeler

 

[JJLAPIN]

Since the paper is white just put that on the top layer of the image you are overlaying and set it to multiply.

 

[IamSam]

@JJLAPIN I actually did think of this, however I had seen where the BG was not completely white so I did not give it a try..............Good catch!

 

[Art4ArtSake]

Thank you both very much for your much appreciated help!

 

[Art4ArtSake]

I would like to add a step that may have been missing from prior examples.
For the Belend If sliders to work and create transparency, the Layer that you have scanned cannot be a Background (locked) Layer as that prevents any transparency.
Once you convert the background Layer to a normal Layer you can create transparency with the Blend If controls.

Also note, I think you would get a better result with a higher resolution scan (up upsizing in Photoshop) by about 4X and the using a Curves Adjustment Layer to increase the contrast in the image before applying the Blend If sliders
Hope the incremental information helps if you have not already solved the problem.
John Wheeler

View attachment 145242

John, thank you very much for that added information. It was most helpful. Have scanned the original image at 1200dpi (or is it now ppi) as a png file. I will go ahead and do as you suggest, using the Curves Adjustment prior to Blend If.

 

[Art4ArtSake]

Since the paper is white just put that on the top layer of the image you are overlaying and set it to multiply.

View attachment 145243

Thank you. A good work around. Also only just learning how to respond on this forum.