Color Range Selection using Lab values

Is there a way to select pixels in Photoshop based on given Lab values? I am using Select --> Color Range with a specified "fuzziness" threshold, but I'd rather make the selection based on specific Lab values instead of random pixels that I choose with my eye dropper. Is there a way to do this in Photoshop, or does anyone know of a plug-in that might do this?
Also, if I end up having to use the basic Color Range tool, I'd like to know what "fuzziness" means. I understand what it does (selects more or less colors based on the threshold around the point you choose with your eyedropper), but what is that based on? A color difference (delta E) value around that point maybe?
I am using Photoshop CS3 v10.0 on a Windows XP machine.
Any help would be greatly appreciated.
Thanks, Ellen

It may be helpful to compare the Color Range command with the Magic Wand Tool. A Magic Wand "selection" is 100% opaque and all pixels outside its tolerannce have zero opacity. So the selected pixels are either totally selected or totally unselected. There is no partial selection.
Not so with the Color Range command. The pixel clicked establishes the "base" color. Whereever that exact color occurs in the image, it is totally selected (100% opaque). The degree to which other pixels are selected (their opacity) depends on the Fuzziness setting.
At zero Fuzziness, all pixels other than those with the base color are totally unselected (zero opacity). As the Fuzziness setting increases, pixels with values other than the base value begin to be selected, but not 100%. There is a bell-shaped (Gaussian) curve of opacity centered on the base value and dinminishing on either side of it.
The breadth of the Gaussian curve (let's define that as the color value difference between 50% opacity on the left and 50% opacity on the right is directly proportional (not equal to) the Fuzziness. Double the Fuzziness and you double the breadth. Marching ants appear at the 50% opacity point. But be careful interpreting this because with the Magic Wand, for example, the 50% opacity point occurs at the same point as zero and 100%, there being no gradation of opacity at the edge of a Magic Wand selection.
You need to be aware also that the Color Range command operates in each color channel and the deviation from base value is determined by the most restrictive of the three channels. If a pixel is within Fuzziness limits for one channel but not another, it doesn't pass muster. And, yes, CR uses Lab colors, but you need not be in Lab mode.

Similar Messages

Color range selection + layer styles

Hello--
Help me if you can!
I have had it on good authority (my photoshop instructor) that color range selection hasn't been working correctly for some time.
I'm using CS2, version 9.0.2 on an IMac os X version 10.5.8.
I am often working with multiple layers that are not similar at all. When I have one layer active and do a color selection, it may also select the color range on inactive layers. Then, if I do a fill, for example, it may affect areas on other layers that were inadvertantly color selected. I know there are ways to ask photoshop to perform a function on all layers, but I don't see this as an option or setting with color range selection. I had started to assume it was sort of like crop, which affects all layers, but when I asked, my teacher says it should only be selecting/affecting the layer that is active.
I found I can deal with this by 'closing the eyes' (making non-visible) the other layers...but that is a hassle and sometimes hides exactly what I need to see.
Then noticed, just lately, that when I use a layer style, it is no longer showing up on my layer palette. Maybe I don't understand correctly, but I thought any layer style addition would show up on the palette under the name of that layer. If I happen to remember that a particular layer used a layer style, I can still click on the layer styles icon and alter it, but it isn't displaying on the layer palette any more--so I cannot toggle or discard the effect simply, and it is hard to know why a layer looks the way it does without that information.
Could be I'm corrupted and need to deinstall/reinstall? Is there something I'm missing about these functions , or something I accidentally changed? I would really appreciate any help or information.

Yes your instructor is wrong, it always selects visible pixels, and always has. You can however create a selection before you go into Color Range, and it will only work within that selection though.
If you want Color Range to work in precisely the same way as it always did in the old versions you need to make sure that you ..
• Highlight a non masked layer and
• Uncheck the somewhat bizarrely entitled "Localised Color Clusters" checkbox
The changes to Color Range happened a few versions ago, to my memory it was with CS4 . The main improvement was that they made it more powerful with the capability to produce better more refined selections. They also unfortunately made the daft mistake of making the command work DIFFERENTLY depending on whether you have a masked or a non masked layer selected. This is not very logical really because it just causes confusion, and doesn't really achieve anything constructive in my opinion. No one who knows what they are doing wants to modify an existing mask using Color Range.

Removing a selection area from a color range selection...

I have an icon I am working with and I have used the color range selection tool to select the background however there are some pixels that were selected that are actually on the inside of the icon itself. I want to remove that selected area. I had do I remove the selected are inside the icon? What about adding pixels to the selection area? How would that be done?

Good day!
The shift- and alt-key usually allow Selection tools to be used to add or subract from an existing Selection.
Could you post the image itself?
Because I suspect in a case like this it would be bette to work with a Selection based on channel/s. Maybe as the basis for a Solid Color Layer.
Regards,
Pfaffenbichler

Color range selection preview

I'm at a new job with a new iMac (Mavericks 10.9.4) and CC. I like using the "color range" selection tool in Photoshop, but I cannot figure out how to make the selected area just show as a marquee area - I don't want it to show as White Matte/Black Matte, etc. - JUST as a marqueed area, with my 4c image still visible. Ideas?

I just have to ask - why?
Once you commit by pressing OK you get your marquee. But the purpose of the selection preview is to show you precisely what will be selected, and a marquee doesn't do that. It would defeat the whole purpose of a preview. This would be easier to answer if we knew what you're trying to do.

Range selection for Fix value variable in BPS

Hi,
When create vaiable, there is a fix value variable, under selection condition, we can choose either multiple single value or range, however if we choose the range, let say mtareial number from 1 to 100, when we run the BPS application through UPSPL, the value for material variable will be populated with value 1 to 100, when I try to change the value to a single value,it's not allowed me to change, while the user define value type, we can change the value, Is this supposed to be?

JW,
BPS variables does not allow the choice of multiple single values, you can choose a single value OR a range of values. This issues has been brought up with SAP Development.
If you need single values or a complete range of values, you can add each single value as a fixed value and the range as another fixed value that can be selected. You can select each single value individually or the whole range (or any subranges you specified) but not multiple selections of single values.
In user definted variable if you check input allowed by users, you can add some values and the users can add more but then they could potentially go into material numbers they should not get access too.
Hope this helps,
Mary

Range selection using the NI 4351 example "435x fast.vi" in LabView 2009.

I am using the NI 4351 DAQ board and the example "435x fast.vi" in LabView 2009. I wanted to add a range function and have the scale labels reflect the proper values. How can I programmatically change the Minimum and Maximum parameter values for the "Y" Axis of the “Scaled Data" Waveform chart properties.
Solved!
Go to Solution.

You can programmatically change the Y axis range as well as many other properties of the waveform chart using a property node. If you are not familiar with property nodes, you can create one for the chart by right clicking the chart in the block diagram and selecting to create a property node. From there you can select what property you would like to change. For your specific question, right click the chart and select Create > Property Node > Y Scale > Range > Minimum/Maximum. Once you create the property node, you'll have to specify that you want to modify properties by right clicking it and selecting "Change all to Write." Each of the properties can then by controlled using a control or constant.
I've attached a basic example (in LV 8.6, let me know if you need older) that modifies the Y axis range of a waveform chart using two controls on the front panel. Note that I have a third property, YScale.ScaleFit, set as 0 by a constant. This programmatically turns off autoscaling on the chart. Autoscaling must be turned off if you want to manually scale an axis. Alternatively you can just turn autoscaling off from the front panel by right clicking the chart.
Hopefully this helps.
Chris G
Applications Engineer
National Instruments
Attachments:
Chart Property Node.vi ‏9 KB

Using cs6, I've tried filling a selection that I've made using "select color range" but the new fill gets diffused and transparent in places

Is there a way of turning this "color range selection" into a normal selection?

Yes
With Color Range there can be stray partially selected pixels all over the place. It best to first make the color range selection and with the selection active switch to the rectangle marquee tool and hold the Alt or option key down and clean up the stray pixel by subtracting large rectangle areas. You will stall have partially select pixels in the area you want solid. You can use a trick I use when I work on layers mask. Layer Mask are grayscale channels. When you paint with Black and White with the brush blend mode set Overlay the white and black areas are protected. Only the gray partially select area will change. So You can save your cleaned up Color Range selection as an Alpha Channel and paint with white to turn the partially select pixels in the Alpha channel to fully selected.
To show how the overlay mode works I could just have saved the color selection as and Alpha channel. Switched to the Channels palette targeted the alpha and cleaned up the selection. I chose to show that overlay blend will even work in RGB mode when you paint Black and White.
After I cleaned up the stray pixels I added a an empty layer on top om the image and filled the selection with black then inverted the selection and filled with white to create a Black and white work layer. Grabbed a black paint brush set overlay mode and repeatedly brushed over the image and drove the gray pixels to black. View screen capture in a new browser tan ans scale it to actual pixels. This sits scale upload images poorly.

Select Color Range, fails v13.1.1 on Retina Display Mac

Is there a trick to getting the new Color Range selection function to work on a retina Mac Book Pro?
I am quite familiar with the color range selection in the previous version of Photoshop, and used it regularly. I've decided to try as simply as possible by using a flat image (no layers), and trying to select colors. I've increased the contrast in the image to make darks and lights much easier to pull out.
I've explored setting the sample size to point-sample up to 3x3, and 5x5. I've also set the resolution of my display to 2880 x 1800 (to reduce the possiblility of anti-aliasing problems).
It will not make any selection though, using the eye-dropper sample.
Using other options will work, such as Highlights, Shadows, Skin Tones, etc., but it won't do anything with Sampled Colors.

SO very glad I'm not the only one with this seemingly EXACT same issue.
System:
Photoshop CS6 via Creative Cloud membership.
Windows 7 Home Premium
16GB Ram
Issue:
Select > Color Range used to work perfectly before update 13.1.1
Now since the update 13.1.1 Color Range doesn't do jack properly. Selecting any color doesn't do anything. sometimes if I select a white it will act as though I've pulled out a gray.. but even one pixel difference will make it deselect. This only happens with Sampled Colors. All otehr color range preselections work as advertised. This would be great if I didn't need the precision afforded to me with Sampled Colors. This is mission critical to my daily work as a scren printing artist and have been unable to find a succesful workaround.
Is there at least a way (without having to uninstall/reinstall) to downgrade back to 13.0.x until this bug is found and fixed?

Photoshop CS3 Color Range Problem

I am having an issue with the color range selection tool in Photoshop CS3 on an iMac G5 running Snow Leopard.
I've been using this tool for years and it's always worked properly until now. It no longer selects the color I've picked with the eyedropper. The only time it works properly is when I set the image to grayscale mode. In any other mode, it selects erratically, like the image below. Those are clean rectangles I created with the paint bucket, so I'm not sure where the lines selected in the Color Range view are coming from. Adjusting
"Fuzziness" doesn't help. The image is set to 8bits. Any ideas?
I've tried using the color range on another computer with the same settings and it works fine.

Is the Eyedropper Tool set to Current Layer in the Options Bar?
If nothing else helps you can always try trashing the prefs (after making sure all customized presets like Actions, Patterns, Brushes etc. have been saved and making a note of the Preferences you’ve changed).

Select-option default value???

DATA: gsber1         like csks-gsber.
select distinct GSBER
into (gsber1)
from csks
where kostl = sch_kostl.
endselect.
SELECT-OPTIONS : gsber    FOR csks-gsber DEFAULT gsber1.
why not input value gsber1?

Pung,
Pls. see the docs. below.
To assign default values to a selection criterion, you use the following syntax:
SELECT-OPTIONS <seltab> FOR <f> DEFAULT <g> [TO <h>] ....
Default values <g> and <h> can be literals or field names. You can only use fields that contain a value when the program is started. These fields include several predefined data objects.
For each SELECT-OPTIONS statement, you can specify only one DEFAULT addition. This means that you can fill only the first row of selection table <seltab> with default values. To fill more rows with default values, the selection table must be processed before the selection screen is called, for example, during the AT SELECTION-SCREEN -OUTPUT event.
You use the DEFAULT addition as follows to address the individual components of the first row:
To fill only the LOW field (single field comparison), use:
........DEFAULT <g>.
To fill the LOW and HIGH fields (range selection), use:
........DEFAULT <g> TO <h>.
To fill the OPTION field, use:
........DEFAULT <g> [to <h>] OPTION <op>.
For single field comparisons, <op> can be EQ, NE, GE, GT, LE, LT, CP, or NP. The default value is EQ. For range selections, <op> can be BT or NB. The default value is BT.
To fill the SIGN field, use:
........DEFAULT <g> [to <h>] [OPTION <op>] SIGN <s>.
The value of <s> can be I or E. The default value is I.
The input fields of the selection criterion are filled with the default values. The user can accept or change these values.
REPORT DEMO.
DATA WA_SPFLI TYPE SPFLI.
SELECT-OPTIONS AIRLINE FOR WA_SPFLI-CARRID
               DEFAULT 'AA'
                    TO 'LH'
                OPTION NB
                  SIGN I.
Don't forget ot reward if useful...

"Select Color Range" not working. "Warning: No pixels were selected" returned when attempting to use. Using Photoshop CS6 on a Mac running OS X Yosemite

"Select Color Range" not working. "Warning: No pixels were selected" returned when attempting to use. Using Photoshop CS6 on a Mac running OS X Yosemite

Here are three screenshots in succession from trying to perform the color selection:
Dropbox - Screenshot 2015-02-12 14.57.40.png
Dropbox - Screenshot 2015-02-12 15.00.14(2).png
Dropbox - Screenshot 2015-02-12 15.01.00.png

PS CS5: select color range not working properly

The color range is a grate command but it doesn't work properly when dragging the eye dropper across the image. This is especially noticeable with a low range value. When you start the selection (without pressing the shift key) and drag across the image only the end point is selected instead of the whole trace. Second, when dragging with the shift key pressed not the trace is added to the selection but a rectangular area. You can easily try this out by creating any one color image and lower the range value to about 5.
In my opinion this is a bug or am I missing something?

Hello,
When you start the selection (without pressing the shift key) and drag across the image only the end point is selected instead of the whole trace.
This behavior is as designed. When you make a selection without holding the shift key, and you have the first eyedropper selected in the menu (the one that doesn't have a plus or minus sign) you are a making an initial selection on the image. If you hold and drag this selection, it will just change the initial selection to match whatever destination you prefer on the image.
Second, when dragging with the shift key pressed not the trace is added to the selection but a rectangular area.
I can reproduce this behavior, too. I believe this is also as designed, because the range is too small to make an organic looking selection. I think the more standard workflow is to start with the range high (100%), make the selection of the localized color area you want to mask, and then reduce the range value as needed.
Color Range isn't terribly intuitive to me, but it can be a powerful selection tool. Photoshop Evangelist Russell Brown has a really good tutorial on Adobe TV about using color range. Have you seen this before?
http://tv.adobe.com/watch/the-russell-brown-show/the-secret-life-of-color-range/
Hope this helps!

Lab Color Range

Hi
In Photoshop the a and b values in Lab color range from -128 to 127, but on wikipedia (http://en.wikipedia.org/wiki/Lab_color#Range_of_L.2Aa.2Ab.2A_coordinates) they are -0.86 to 0.98 and -1.07 to 0.94 respectively. Is this just a usability thing in Photoshop? Can I plot the Photoshop values on a graph (http://en.wikipedia.org/wiki/Image:CIExy1931.svg) by using ratios to convert the values?
Thanks!
Chris

Hello Chris,
What are you trying to do? Do you want to get into all the math and complexities of 3 dimensional space and Euclidean Distances or are you interested in understanding and using LAB for practical purposes. If it's the latter, then there are a lot of tutorials floating around and the Photoshopper's bible on lAB - a book by Dan Margulis called "The Canyon Conundrum and Other Adventures in the World's Most Powerful Color Space". If however you want to get into all the math and science, you would probably be better off checking out the CIE org.
Regards, MM

Selection with color range based on a channel

I want to select highlights from a channel with the color range ...
I select "hightlights" on the color range window.
Then, which values of the fuzziness and range sliders should I use for selecting highlights equal to the selecting them with ctrl + click on that channel?
Thanks ...

lost,
As I understand this problem, you have a series of numbers in column B and you want to add the last n items (number shown in column A of current row) to the current row. In column C of the current row place the formula:
=ADDRESS(ROW()-A7+1,2)&":B"&ROW()
then in column D your result: =IF(ISBLANK(C),"",SUM(INDIRECT(C)))
pw

Select- Color Range- Results in Blue Screen (PC) (driver out of date)

I've been using the CS6 beta about two days. While experimenting with color range I experienced two consecutive blue screen crashes. The first time it happened,I was working with the color range selector and was replacing the selected areas with another color using the paint bucket. About the third time I attempted this, my PC blue screened. The second time, I opened a photo, went to Select>Color Range and got an immediate blue screen crash.
I then went back to CS5 and I've been playing with the same scenario with no apparent problems.
My PC is a store built computer. It consists of an MSI 990-FXA GD80 motherboard, an AMD Phenom 1100t CPU, Asus GTX550 Ti graphics card and 8 gig of RAM. It boots from a 60 gig SSD and my programs reside on a 500 gig hard drive. The OS is Windows 7 Professional 64 bit. CS6 is using the hard drive for its scratch disk and Photoshop is using 4339 mb of the 7232 mb of available RAM - I haven't changed that. I'm running CS6 as administrator because the way it installed, it would only run in that fashion.
One disappointment during the installation was CS6 made no attempt to read my preferences from the CS5 install. That may be covered in another post, I've not yet looked.
Please keep us informed as new betas are released, because I would like some time to work with this puppy before plunking down big bux for the upgrade. As it is now, I'm going back to CS5. I get mighty nervous when my super computer blue screens!
Gerry
gswetsky AT bellsouth DOT net

The GPU is often at root of issues like yours. I've had so many problems with Nvidia drivers for their gaming-oriented adapters (like yours) that I finally went with one of their workstation cards. I have a Quadro card with just enough RAM to make Photoshop happy. The workstation drivers are optimized for reliability, the consumer card drivers are optimized for gaming and that often means they're less stable and reliable with Photoshop.

Color Range Selection using Lab values

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