Time information in TIFF files

I am using "imwrite" and "WriteMode" "Append" to create a multi-tif file (a movie). I would like to include information about the time that each tif image was created in the multi-tif file. How do I add time information to the tif files?

Answer 1

[John]

There is a tag called 'DateTime' that is intended for this purpose, but IMWRITE can only write a limited subset of TIFF tags, and 'DateTime' is not in that subset.

The Tiff object (introduced in R2009b) can manipulate a much broader set of tags, so it may suit your purposes better than IMWRITE. For example, to write out a multi-page TIFF consisting of the first through the 12th eigenfunctions of the L-shaped membrane, one could do something like the following:

t = Tiff('myfile.tif','w');
tagstruct.ImageWidth = 31;
tagstruct.ImageLength = 31;
tagstruct.Photometric = Tiff.Photometric.MinIsBlack;
tagstruct.BitsPerSample = 64;
tagstruct.SampleFormat = Tiff.SampleFormat.IEEEFP;
tagstruct.RowsPerStrip = 31;
tagstruct.PlanarConfiguration = Tiff.PlanarConfiguration.Chunky;

for k = 1:12
      data = membrane(k);
      tagstruct.DateTime = datestr(now,31);
      t.setTag(tagstruct);
      t.write(data);
      t.writeDirectory();
end

t.close();

The 'DateTime' tag is limited to 20 characters, so if you need more temporal resolution than that, you might have to hijack another tag for your purposes, such as 'ImageDescription' or 'XMP'.

[Angelina]

this date datetime function only provides you with the modified time, not the time the file was created. is there a way to extract the creation time of the image?

[Walter Roberson]

In the above context, you could record the value of "now" before the loop, and then use that recorded value each time through; that would ensure consistent times for each of the multi-page TIFF items being constructed.

But your question here is about extracting the creation time, whereas the above code is about setting a time tag. You already started a Question about extracting the times.

[Angelina]

I see, oversight on my part. Thank you for clarifying!

[Xiaoli]

To write in append mode change 'w' to 'a'