Posted by
Stephan Saalfeld on
Jan 31, 2011; 1:36pm
URL: http://imagej.273.s1.nabble.com/Merging-of-Images-tp3685871p3685877.html
Dear Elizabeth,
if you combine the two channels into a composite image then you have
this option in the result. For each channel, you can choose its color
with the Channels tool, trigger each channels contrast settings
individually and, in case you really want that still, convert that into
an RGB image.
Using the merge tool, you can achieve the magenta/green combination
directly choosing red:image1, green:image2, blue:image1.
For combining arbitrary color schemes, you could apply the desired
channel-LUT to each of your individual channels, convert each of them to
RGB and then use Process->Image Calculator to ADD them. This is
essentially what the color merge tool is doing.
Best,
Stephan
On Mon, 2011-01-31 at 14:19 +0100, Crowell Elizabeth wrote:
> Hello,
> On a related subject, while it's true that it may be impossible to
> produce color figures that will be understandable by all types of color
> blind people, it seems that the red/green/blue combination is one of the
> least desirable.
>
> Yet, the red/green/blue colors are the only colors proposed in the
> Image/Color/Merge Channels tool.
> Perhaps it might be worth considering allowing the use of more generally
> discernable colors, like the widely used magenta/green combination or
> blue/yellow combination noted below. It would be nice, I think, to have
> these other colors easily accessible in the Merge Channels tool.
>
> What do the other users think?
> Regards,
> Elizabeth Crowell
>
>
> Gabriel Landini a écrit :
> > On Monday 31 Jan 2011 11:55:00 Phase GmbH wrote:
> >
> >> I am faced with the following problem:
> >> A microscopic sample is labelled with 2 fluorescent dyes, one emitting red
> >> the other yellow. 2 Images are taken by a black/white camera, one for the
> >> red label one, one for the yellow label. Every Image is colourized by a
> >> applying the corresponding LUT.
> >>
> >> My question is know: What would be the best procedure to merge both images?
> >> The final image should show both labels in their correct colours.
> >>
> >
> > You can mix yellow and red but this will be a confusing orange, as the hues
> > are not that far away to produce a new distinct additive colou mix.
> >
> > I would rather put the "red" greyscale image (i.e. without LUT) in the blue
> > channel and the yellow signal (which you caputured in greyscale as well) in
> > both the red and green channels.
> > This way ther "red" appears as "blue" and the "yellow" still as "yellow".
> > Cololocalisation appears as white. This can be seen correctly by the vast
> > majority of viewers, including all red-green colour blinds (e.g. protanopes,
> > deuteranopes, and anomalous prot- and deu- dichromats). Another advantage is
> > that they will perceive the colours with the correct names (unlike with the
> > green-magenta pairs that some use). Tritanopes however (a very small
> > proportion of dichromatic viewers) might struggle to see the differences.
> > There is no solution that fits all and preserves colour name perception.
> >
> > Note that the "correct colours" is somewhat misleading as there is no
> > guarantee that the RGB LUT matches the emission spectrum of the dyes.
> > I gave a talk on this subject at the last Luxembourg meeting.
> >
> > Regards
> >
> > Gabriel
> >
>
>