How to create a series of separate tiff files?

I am trying to create a new TIFF file to append images to. For some reason this code does not work. I need to create several different tiff files to append different images onto each one.

thresholdarray = [0.01, 0.1, 0.001];
medfiltarray = [2, 8, 10, 16];

for i = 1:3
    thresholdvalue = thresholdarray(1,i);
for j = 1:4
        medfiltvalue = medfiltarray(1,j);
        s1 = 'GFPthreshold:';
        s2 = num2str(thresholdvalue);
        s3 = 'medfilt:';
        s4 = num2str(medfiltvalue);
        s5 = '.tif';
     tiffname = strcat(s1,s2,s3,s4,s5);
     tiff = Tiff(tiffname,'a');
end
end
%%this line of code works:
   tiff = Tiff('newtiff.tif','a'); %this creates a new tiff file in my file path
% why doesn't the loop work?

Answer 1

[Walter Roberson]

Your filename includes a colon . colon is not a valid character in a filename for Windows (other than for drive letter) or MacOS

Answer 2

[Chunru]

It works here (in a unix environment). You may want to change ":" in file names into "_" for windows.

thresholdarray = [0.01, 0.1, 0.001];
medfiltarray = [2, 8, 10, 16];
for i = 1:3
    thresholdvalue = thresholdarray(1,i);
    for j = 1:4
            medfiltvalue = medfiltarray(1,j);
            s1 = 'GFPthreshold:';
            s2 = num2str(thresholdvalue);
            s3 = 'medfilt:';
            s4 = num2str(medfiltvalue);
            s5 = '.tif';
         tiffname = strcat(s1,s2,s3,s4,s5);
         tiff = Tiff(tiffname,'a');
    end
end
dir

.                                 GFPthreshold:0.001medfilt:16.tif  GFPthreshold:0.01medfilt:10.tif   GFPthreshold:0.01medfilt:8.tif    GFPthreshold:0.1medfilt:2.tif     
..                                GFPthreshold:0.001medfilt:2.tif   GFPthreshold:0.01medfilt:16.tif   GFPthreshold:0.1medfilt:10.tif    GFPthreshold:0.1medfilt:8.tif     
GFPthreshold:0.001medfilt:10.tif  GFPthreshold:0.001medfilt:8.tif   GFPthreshold:0.01medfilt:2.tif    GFPthreshold:0.1medfilt:16.tif