Difficulty in selecting very similar pixels

[cooniebear]

Yesterday I had a huge scanned map (not a GIS funcational map) in which I was supposed to replace the outer, light aqua areas with a color that was different than the water which is a little darker blue. I got this project, it had to be done in 15 min, needless to say I thought it was a cinch but when I went to select 'similar' it ended up selecting all the blues, no matter what value I put in the tolerance. I also looked at the channels and copying the layers on top of one another with different blending modes to see if I could isolate this lighter aqua layer without selecting the major waterways. I ended up doing it all my separate selections today (took me 4 hours) but was hoping there was another way so I don't get caught with my pants down next time. Oh, and I also used the 'replace color' feature and it again selected the whole water, (light and dark blue). Partial sample included on website: tribal map.jpg.

 

[MarcusStringer]

Did you try using Select>Colour Range?

Also just simply drawing a marquee around the area???

Marcus

http://www.midlandtypesetters.com.au

 

[jmgalvin]

When you select the magic wand, you can do a lot with the tool prefs that show at the top of the photoshop workspace.

If you had first clicked on the color and then clicked "add to selection" you could have just clicked all areas that had the color you wanted to change and filled them - similar to shift clicking.

You could also decrease the tolerance. This narrows the color range selected and the "select similar" is also narrower.

Another trick is to use various adjustments under the image menu. If you play with hue/saturation you can increase the contrast is certain areas (possibly) and avoid all the selecting.

Using OSX 10.3.9 on a G4

 

[cooniebear]

I have tried the color range and it didn't work. It seemed like it was going to because I had shift-selected several colors in the range I wanted but then when I hit the OK button it didn't grow the selection.

If I could figure out how to attach an image to this page I would show you how many areas there were, and how similar the colors were.

Thanks for the replies.

 

[MarcusStringer]

You can upload images here:

http://photobucket.com/

Colour range is only really good for one colour at a time

Marcus

http://www.midlandtypesetters.com.au

 

[cooniebear]

I finally got an image uploaded, thank you Marcus. It's at

http://s71.photobucket.com/albums/i123/cschiff_photos/?action=view&current=map.jpg

If you can see the middle lake, the outside of the lake is just a little bit lighter and this is what I was trying to select.-

 

[MarcusStringer]

If you slide your fuzziness down to about 82 on the selected area.

I did that and got about 99% of the lake

Marcus

http://www.midlandtypesetters.com.au

 

[cooniebear]

Marcus, what tool are you using? I don't understand 'fuzziness'. I was just using the magic wand. Is there another tool I should be using?

 

[cooniebear]

Never mind. I see now that you were using the Color Range. But when I use that number, the entire middle lake gets selected with a fuzziness of 92. I only wanted the outer, light aqua pixels. Marcus,thanks.

 

[blueark]

Just lower the fuzziness to about 25. There's quite a bit of noise in the image though, so you may need to shift-select a few samples to get the area you're looking for.