Selection of areas with very similar colors and tones

[Rufkraft]

Hello All,

I've been running into a selection headache here and there and was hoping I could get some fresh ideas. Here the deal: Making a selection of two very similarly colored images and/or removing a similarly colored image from a background. I tried a few things so far, such as a low tolerance magic wand, similar select, duplicating the image and squeezing the levels and exposure to extreme contrast then apply the selection to a mask...I usually end up brushing out a vector mask or using the pen.

Just wondering if anyone as any insights or could point me in the right direction on simplifying the process. Its something I run into often and sometimes in large volumes. Thanks for the read and I'd just like to say this forum is awesome..Cheers!

 

[MrToM]

Adding a 'Levels' adjustment layer brings out the detail from which the 'Quick Selection' tool on one of the channels does a reasonable job...



I guess it really depends on how accurate you need to be, the speed at which you need to do it and the quality of the image.

No doubt there are better ways.

Regards.
MrToM.

 

[Rufkraft]

Awesome. Thanks MrToM. I haven't worked with channels yet although I know that I should. Gonna go watch a few tutorials right now. If anyone knows of a great one or has a favorite a link would be much appreciated.

 

[MrToM]

Don't mistake this for using channels to create the selection....that's a totally different method.

I just used 'a' channel as the image on which to use the 'Quick Selection' tool......a greyscale image is often easier for the tool to work on.

Regards.
MrToM.

 

[Tom Mann]

I understand exactly where you are coming from. In a situation like this, I try to get as close as possible, very quickly, by automated or semi-automated methods, then, if necessary, touch up either the selection or the associated mask by small manual tweaks.

My usual technique to very quickly develop a reasonable approximate selection is to do the following things to the image, in the order listed:

1) De-noise it, without losing any more real detail than is absolutely necessary;

2) Apply local contrast (ie, NOT global contrast like you did) by applying unsharp masking to the de-noised version. For this image, I used a radius of around 40 px, and an opacity of around 40%;

3) Greatly increase the color contrast. For this image, I used two applications of a vibrance/sat adjustment layer, each with the vibrance slider maxed out.

4) I then merged all of the previous adjustments into one layer, saved the result as a working (but not final) file, should I ever have to go back to it, and then used the Quick Selection tool, first on "add to", and then "subtract from" modes to clean up any areas incorrectly selected, adding a final "refine edges" step if necessary.

The above steps are almost exactly the same for any image with low contrast edges, and can be placed into an action, if you want.

Below is the result of the above steps overlaid as marching ants on the original image. If It was important enough, I could tweak this quick-and-dirty preliminary selection by all the usual techniques, but I usually just paint black and white, as needed, on the corresponding mask.

How does this compare to what you obtained?

Tom M

PS - The truth be told, if the edge is irregular, I almost always take this approach, or some variant of it, and only make a selection using the pen tool if the object has simple geometric edges, like many man-made objects have.

 

[Tom Mann]

PPS - depending on whether the cut-out is going to be over a dark or light background, I may further modify the selection. Often, this only involves globally expanding and/or contracting and/or feathering the selection by a pixel or so.

 

[Tom Mann]

Oh, I see that I forgot to include the contrast and color enhanced version of the original image to which I used the quick selection tool. Here it is ...

 

[Tom Mann]

PS #3 - FWIW, the Quick Selection tool definitely makes use of color boundaries, if present, so, unlike MrToM, I work in color if at all possible.

T

 

[Rufkraft]

Great Tom! Definitely some things that I have not tried. The idea of creating an action hadn't even crossed my mind. My results were not as clean for sure. This particular project also has a lot of curvy/wavy edges so the pen tool, and my knowledge of it, wasn't really the go to. The color contrast goes a long way!

 

[Tom Mann]

Great! Let us know how it goes.

Cheers,

Tom M