Eliminate grid in background

[Tyler Nam]

Hello,

My laboratory is studying plant roots and we took these pictures of the roots that we want to separate from the background. We took these pictures on a grid background that unfortunately matches the color of the roots.  This makes the magic wand tool finicky.  We have many of these images and do not have the time to go through and manually crop out the grid from the background of each picture.  Is there a quick and reliable way to only keep the root in the image? 

Here is an example of the picture we want to separate the root from the background.

and here is an example of what we want it to look like.  The dot and rectangel are scale markers, you don't need to worry about those.

Any help is appreciated!

Thank you.

[S_Gans]

Oh - this would have been so much easier, without it also being a yellow/gold grid. There's not going to be a magic fix to this one, but the blue being the opposite side of the color wheel from yellow will help.
I think the most efficient way would be to work with channels for your selection. (PreviewPreview11:05Insanely Difficult Selections MADE EASY with Alpha Channels ...YouTube · Photosho...)

In the attached video, I used a hard edged paintbrush and the bracket keys to enlarge and shrink the brush (just did a bit, to give you an idea).
In the end, you will have to go in and edit the grid by hand - but remember - to paint a straight line, click one end, then shift click the other.

[Chris 486]

Hi Tyler!

S_Gans has a great solution here. The yellow grid color in the background competing with the root itself. If by chance you have anothe color grid option, using the color range selctor could be a quick option in the future.

Select color ranges in Photoshop (adobe.com)

A couple of videos showing it in action:

https://youtu.be/n9fwiNyDHLI?t=79

https://youtu.be/8nk1KkLn3CM?t=196