Help selecting a poorly defined area in an image.

[Raamegil]

So, I am trying to select the thorns/rose seperately in the attatched image, but because of the varying levels of definition of the borders, I cant see any way to do so other than by hand pixel by pixel. Are there any addons that make this task easier, or is there a simple function that I have just not seen.

 

In case it helps, my goal is to overlay it on three seperate colored layers, and "cut through" the lower layers with the top layer set on multiply, that way coloring the details while leaving the shading intact.

 

 

http://i.imgur.com/LWPbWTq.png

Edited June 7, 2013 by Raamegil

[yellowman]

Use lasso tool with Add (union) mode, but bear in mind, the Multiply blend mode will apply on the whole layer no matter if there are selections or no. Or maybe I didn't understand your question correctly.

[Ego Eram Reputo]

Here's how I would approach this: 

 

First - I think it's a manual job.  There is just too much of the same color and texture to make an automatic selection of individual elements easy.

 

1.  Duplicate the layer.

2.  Rename it "Rose"

3.  Hide lower layer & activate the upper layer (Rose)

4.  Make a rectangular selection just around the rose.  Press Ctrl + I to invert the selection and press Delete.

5. Activate the Eraser and increase the brush width to about 20 and zoom in a couple of steps.

6. Carefully erase around the border of the rose in small steps.  I even get down to single clicks to do a nice job.

 

 

7. When done.  Repeat steps 1-6 for the thorns (rename it thorns )

[Raamegil]

Ah, okay, thanks, I was thinking that there could be some kind of tool that only selects as long as the pixels are darkening, but that may not even be possible, but thanks for the tip to do it that way, I was too set on the idea of erasing the inside that I forgot to consider inverting my plan.

[gregors]

Magic wand tool selects pixels of "similar color" use the "Tolerance" slider at the top of the application window to adjust how similar tha selected pixels are to be... "Add" or "Subtract" or "Intersect" etc your selection to get what you want selected.

Ego Eram Reputos suggestion of putting the different items on different layers was (I assume) your original intention, if not it definitely is the way to go!