Posted by
ram prasad on
Sep 02, 2015; 8:39am
URL: http://imagej.273.s1.nabble.com/Batch-color-thresholder-tp5014215p5014221.html
Hi Oli,
Thank you very much for your response.
When I select "Macro" from the threshold color, it gives me a macro code
and a red coloured mask on the area of my interest. However, when I try to
create a selection on this mask I get the error I mentioned in the first
mail in this thread.
"However the question remains on what you are trying to measure on your
original RGB image. From what I gather if you measure inside a selection,
you will get the average of the red green and blue channels where you want
the 'yellow color intensity' which is not really that."
I was under the impression that selecting yellow pixels with the hue slider
should give me a selection that has only yellow pixels. That way when I
measure saturation I should get the intensity only for the yellow pixels?
I'd like your opinion on this one.
Herewith, I have attached two images that show a difference in the
intensity (one is yellow and the other one is pale), for your reference.
This difference is what I would like to measure.
Best,
R
On Tue, Sep 1, 2015 at 5:12 PM, Burri Olivier <
[hidden email]> wrote:
> Hi,
>
> If you select "Macro" from the Threshold Color window, it will give you a
> macro code you can run and get a mask that you can use "Create Selection" on
>
> However the question remains on what you are trying to measure on your
> original RGB image. From what I gather if you measure inside a selection,
> you will get the average of the red green and blue channels where you want
> the 'yellow color intensity' which is not really that.
>
> I'd like others' opinions on this, but a better approach once you have
> your mask is to measure the Brightness component of your original image
> converted to HSB stack (Slice 3).
>
> Best
>
> Oli
>
>
> > -----Original Message-----
> > From: ImageJ Interest Group [mailto:
[hidden email]] On Behalf Of
> > ram prasad
> > Sent: Tuesday, September 1, 2015 16:08
> > To:
[hidden email]
> > Subject: Batch color thresholder
> >
> > Hi all,
> >
> > I would like to quantify yellow colour intensity on a number of images,
> but I
> > am having trouble writing a macro for that purpose.
> >
> > I can get as far as opening the colour thresholder and applying my
> cut-off's
> > but then selecting the region of interest is a bit slippery and I'm
> hoping you
> > guys can help me out with this.
> >
> > This is what I'd intended to do.
> >
> > 1) Create a duplicate of my image (Image -> Duplicate)
> > 2) Open the thresholder and select yellow pixels using the hue slider
> (Image -
> > > Adjust -> Threshold)
> > 3) Then create a selection (Edit -> Selection -> Create selection)
> > 4) Restore the selection on the original image (Edit -> Select -> Restore
> > selection)
> > 5) Finally, measure Integrated density using (Analyze -> Measure)
> >
> > The problem I have with the third step is that when I try to create a
> selection
> > (using Edit -> Selection -> Create Selection) I get a pop-up with the
> following
> > message,
> >
> > "This command creates a composite selection from a mask or from an image
> > that has been thresholded using Image -> Adjust ->Threshold tool. The
> > current image is not a mask and has not been thresholded"
> >
> > I'm not sure why I'm getting this error here as I used Image -> Adjust
> > ->Threshold to threshold my image.
> >
> > I'm attaching a sample image here for your reference. Please let me know
> if
> > you need more information from my side.
> >
> > P.S the click operation on the Select button in the thresholder dialog
> box
> > does not get recorded in the macro recorder that's why I'm resorting to
> Edit -
> > > Select -> Create selection to create a selection.
> >
> > Thanks,
> > R
> >
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http://imagej.nih.gov/ij/list.html>
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