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Re: non-destructive 2 channel merge question

Posted by ctrueden on Mar 17, 2011; 6:16pm
URL: http://imagej.273.s1.nabble.com/non-destructive-2-channel-merge-question-tp3685343p3685344.html

Hi Mike,

The "Merge channels" command will destructively remap your data to create an
RGB image. The problem with RGB images is that they are limited to exactly
three 8-bit color channels.

I suggest you avoid using RGB images, and instead use the "composite image"
feature. You can display multi-channel 16-bit data, for example, with a red
and a green channel, without altering the color values.

You can save a composite image to a TIFF with each channel as a separate
plane, preserving the bit depth.

You can also use the Bio-Formats importer to display your image as red-green
without all the steps you describe. Just change the "Color mode" to
"Composite" and it should do what you want.

-Curtis

On Thu, Mar 17, 2011 at 8:39 AM, trshrthrth rdthjdrtjdrtj <
[hidden email]> wrote:

> Hi folks,
>
> I am using imageJ v1.44n6 and I am working with a 2 channel (red/green)
> timelapse movie with Z-sections.
>
> I open this file with LOCI bioformats and use the “split channels”
> function. I then use the following to get a red/green overlay which i then
> save to .tif: image > color > merge channels > select the 2 channels > leave
> “create composite” blank > click ok.  However, I noticed that if prior to
> merging the 2 channels I have adjusted pixel intensities using the
> window/level tool, these are destructively carried over into my merged RGB
> file.  Is there a way to avoid this?
>
> I want to create an image where red and green are overlayed, but where the
> pixel intensities in both the red and green channels represent those of my
> raw data.  Really, the question is how does one create a red green overlay
> and save to .tif without destructively altering pixel intensity values.  Is
> it just a matter of avoiding using the window/level tool before merging??  I
> like to be as non-destructive as possible before getting my output .tif file
> into photoshop.
>
> Many thanks for your help.
>
> Mike
>