Hi Sylvie,

ImageJ can do this easily. I assume that you have 8-bit tiffs 
(monochrome, even if it has a color palette assigned. ou may need to 
change to grayscale and change bit depth to 8-bits. Those are also easy 
operations. Then, in ImageJ (use a current version, I have ver 1.42 and 
it works), just open the images (they must be open), and use "Image | 
Color | Merge Channels" and it allows you to assign the open images to 
the R, G, B, and grayscale channels so you can merge red, green, and 
blue + DIC images for example.

Dale

Sylvie Le Guyader wrote:
> Hi everyone
> 
>  
> 
> Does anyone know of a simple freeware to overlay/merge Tiff images of
> identical size but eg different channels? 
> 
>  
> 
> I searched the ImageJ wiki for new plugins but have only found the good old
> RGB gray merge which is fine when one has only a few images to overlay (too
> many clicks required!) and doesn't need to adjust the levels for each
> channel. I also had a quick look at BioimageXD but it seems that I cannot
> open TIFF images that are not stacks. 
> 
>  
> 
> Any advice?
> 
>  
> 
> Med vänlig hälsning / Best regards
> 
>  
> 
> Sylvie
> 
>  
> 
> @@@@@@@@@@@@@@@@@@@@@@@@
> 
> Sylvie Le Guyader
> 
> Dept of Biosciences and Nutrition
> 
> Karolinska Institutet
> 
> Novum
> 
> 14157 Huddinge
> 
> Sweden
> 
> +46 (0)8 608 9240
> 
>