diff --git a/main.m b/main.m
index 397b850..8a788e2 100644
--- a/main.m
+++ b/main.m
@@ -19,7 +19,7 @@
 save(fn, 'data_g', 'data_r', '-v7.3');
 %% load files
 %if you haven't used the shiftCorrection you have to load the already processed files
-fn_green = 'processedData.mat';
+fn= 'processedData.mat';
 load(fn);
 %% 1. PCA
 %calculate PCAs
diff --git a/readTif.m b/readTif.m
new file mode 100644
index 0000000..2e5e45a
--- /dev/null
+++ b/readTif.m
@@ -0,0 +1,28 @@
+function out = readTif(fName)
+% Function for speed-optimized reading of tif files, ignoring all meta-data
+% and dimension sorting 
+
+ww = imfinfo(fName);  % Tif file information
+nCol = ww(1).SamplesPerPixel;  % Number of color channels (NOT TESTED!)
+nImg = numel(ww);  % Number of frames
+if ww(1).BitsPerSample(1) <= 16
+    out = zeros(ww(1).Height, ww(1).Width,nCol, nImg,'uint16');
+else
+    out = zeros(ww(1).Height, ww(1).Width, nCol, nImg);
+end
+readLength = [ww(1).Width ww(1).Height]; % order has to be reversed for correct reading of data (don't know why)
+gl_fid = fopen (fName, 'r', 'l');
+for j=1:nImg
+    for col=1:nCol
+        fseek(gl_fid, ww(j).StripOffsets(col) , 'bof');
+        if ww(j).BitsPerSample(col) <=8
+            out(:,:,col,j) = uint16(fread(gl_fid,readLength, '*uint8'))';
+        elseif ww(j).BitsPerSample(col) <=16
+            out(:,:,col,j) = fread(gl_fid, readLength, '*uint16')';
+        else ww(j).BitsPerSample(col)
+            out(:,:,col,j) = fread(gl_fid,readLength, 'uint32')';
+        end
+    end
+end
+fclose(gl_fid);
+out = squeeze(out);
\ No newline at end of file