Remove background from plastic wrap - part 2

[jonas.sandstedt]

Found this old question, I wanna do a similar thing (remove the background from a plastic wrap that has been photographed on a white background, but wanna keep both the highlights and the shadows, and also export it as a transparent png (so all blend-modes need to be flattened somehow). Anyone knows how to solve this?

[Mylenium]

It would be helpful to actually see your image. Regardless of this you will probably not find a simple and elegant way of doing this, especially if you want to retain the highlights and will have to do some masking. Pixels are pixels and PS doesn't really know a white highlight from a white background. Anyway, we have to know more.

Mylenium

[jonas.sandstedt]

It's the same as in the original question. Can't attach the acctual image, but it's similar to this:

So there is a white background around the object that you can just remove as usual with masking. But then you need to find the shadows and keep them like 90% opacity, find the highlights and make them 100% in opacity (non transparent) and the find the middle tones and make them maybe 50% in opacity. I don't know exact value, just want to be able to eg place a image behind the image. Understand that Photoshop can't do this automatically , just need to find a good workflow.

(Gonna use it on the we with animation so dont wanna use blend-modes in CSS for performence reasons.)

Have tried with some color range stuff with selecting highlights and find a good range. But feels like there is a best practise or smarter way to solve this.

[Norman Sanders · Accepted solution]

From what you have written I assume you have used the pen or other tool to establish the object perimeter and create a mask so that the object is on a transparent background.

This is how you can:

  A. Locate the precise tonal extremes of this grayscale object’s current tonal scale

  B. Place your chosen values at those points and a midpoint.

Locate End Points 

1. Add an adjustment layer and choose Threshold

2. Move the slider all the way to the right; the image will go completely black.

3. Inch the slider to the left until the first white patch appears. It is the Highlight extreme.

4. Choose the Color Sampler tool. (It is nested with the Eyedropper tool in the Tools panel.) Click in that highlight location. The Color Sampler will mark the site. We will call it Endpoint #1.

Next:

5. Move the slider all the way to the left; the image will go completely white. Inch the slider to the right until the first meaningful black patch appears.

6. Choose the Color Sampler tool. Click in the shadow location. The Color Sampler will mark the site. We will call it Endpoint #2.

7. You no longer need the Threshold layer, so drag it to the Trash. The points you marked will remain. You have now successfully located and marked the important end points. They appear on the object.

Place and Adjust End Points and Midpoint

8. Choose Image > Adjustments > Curves

9. Hold down the Cmd key and click on End Point #1

10. Hold down the Cmd key and click on End Point #2

11. Hold down the Cmd key and click on the midpoint between them

12. At this point, by choosing each marker and using the North and South keyboard arrow keys to bend the curve, you can place their desired values on the curve and the object. Use the Output values as your guide.

Last, remove the markers: With the Color Sampler tool chosen, click on the word Clear that appears in the Options bar.

You are ready to flatten the file and save it as PNG.