Help with overlaying or blending

[Faria31988192x5tu]

Hi, I need help with blending two images together. The bottom image is a regular photograph and the top image is complex multi smeared paint oil pain on a sheet of clear plastic/acrylic, photographed on white or gray backgroudn. Some areas of the paint is opaque and some ares are see through.. How can I achieve that? 

3 images are:

1. Image of the paint on plastic  the white/gray bacground

2. The painted plastic againt a photograph (the goal of the final result)

3. The photograph on the underneath 

The image of the paint needs to be on it's own layer with trasnparent and opaue in the correct areas 

[D Fosse]

You need to make a mask of the areas you want to be transparent. Photoshop has a wide range of selection tools for this.

You're basically asking "how does Photoshop work", which is way too wide for a single post in a forum. I don't want to sound dismissive, but I think the best thing you can do is look up some tutorials about selection and masking.

[c.pfaffenbichler]

The photograph of the paint may not have been well thought through. 

The background seems similar in color and luminance to parts of the paint and it is contaminated by the shadows of the paint which muddles luminance as a factor for separation. 

I think you may want take that photograph anew with more consideration paid to its intended use. 

[c.pfaffenbichler]

If you cannot take the image of the paint again I would recommend using the a- and b-Channels of a Lab-copy of the image to try and isolate certain areas and try to amend the result by painting. 

Certain parts may need to be painted outright themselves (the light bluish-green strokes possibly) because the contrast is too weak and the color appears »muddied« in the photograph. 

[Faria31988192x5tu]

Thanks for your message!  Let me explain better what I'm trying to do. The images I'm working with are much larger and detailed than the images I sent. The closest I've got to achieving what I need to achive is the file Test1b.tif that Im attaching with this messages. I need the opaque and the translucent parts of paint parts all to be on top of the image underneath, as if the image of the paint on clear plastic was been photographed directly on top of the image underneath... shadows included.

One the file I attchaed to this email, if you look around the top left area of the image, I earsed some of the trasnlucent white so you can see the background and see how close I am to achieving what I want to achive without all the different layer masks and paitning in and out. I'm hoping maybe that might spark an idea in you on how to resolve with a quicker method. 

[D Fosse]

I already said what you need to do: make a mask. Don't erase; make a mask.

But you really need to reshoot this to maximize the contrast. This isn't working. You need to give Photoshop something to work with. The easiest is probably a dead black background, but make sure to avoid any reflections.

This is all just pixels in the image. There has to be someting that makes one set of pixels different from the others - and there isn't here.

[Faria31988192x5tu]

I have a copy of the image on black but then I dont get the shadows that need to be showing.

As far as reflection goes. Are you saying when the image of the paint gets photographed it can't have bright highlights?

Let me show you the a couple of images:1

One is the paint against the black background. 

The other two are examples of what it needs to look like when its placed on top of the image

I'm familiar with selection and masking and I can watch more tutorials on them, as you suggested. Meanwhile, if you can give me some step by steps run down series on how to get the results I'd greatly appreciate it

[c.pfaffenbichler]

I have a copy of the image on black but then I dont get the shadows that need to be showing.

Then you need to create the shadow. 

If you can not meaningfully isolate the paint in the photograph isolating the shadows on the background seems difficult/unlikely. 

Your original example seems to demonstrate that. 

If you cannot photograph against a background of a color that is essentially absent in the paint to allow a »chroma key« (which offers its own issues) then the black background enables a decent starting point, but it naurally still needs manual editing to maintain the darker shadows in the paint. 

And the edges will probably have to be decontaminated in some way. 

[Faria31988192x5tu]

Ok, thank you for your help.