MATLAB Answers

Geoffrey
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creating a new TIFF tag field ?

Asked by Geoffrey
on 21 Apr 2016
Latest activity Answered by Geoffrey
on 22 Apr 2016
Hi everyone, I would like to create a new Tag entry in TIFF metadata. I tried :
tags.angle_roll = 0.5698;
geotiffwrite('test1.tif', A, R,'TiffTags',tags);
And I get the error :
Expected TiffTags.angle_roll to match one of
these strings:
'Artist', 'Compression', 'Copyright', 'DateTime',
'DocumentName', 'DotRange', 'ExtraSamples',
'FillOrder', 'Group3Options', 'Group4Options',
'HalfToneHints', 'HostComputer', 'ICCProfile',
'ImageDepth', 'ImageDescription', 'InkNames',
'InkSet', 'JPEGColorMode', 'JPEGQuality', 'Make',
'MaxSampleValue', 'MinSampleValue', 'Model',
'NumberOfInks', 'Orientation', 'PageName',
'PageNumber', 'PhotometricInterpretation',
'Photoshop', 'PlanarConfiguration',
'PrimaryChromaticities', 'ReferenceBlackWhite',
'ResolutionUnit', 'RichTIFFIPTC', 'RowsPerStrip',
'SGILogDataFmt', 'SMaxSampleValue',
'SMinSampleValue', 'SToNits', 'Software',
'TargetPrinter', 'Thresholding', 'TileLength',
'TileWidth', 'TransferFunction', 'WhitePoint',
'XMP', 'XPosition', 'XResolution',
'YCbCrCoefficients', 'YCbCrPositioning',
'YCbCrSubSampling', 'YPosition', 'YResolution',
'ZipQuality'
The input, 'angle_roll', did not match any of the
valid strings.
So is it impossible to create a new Tag entry in tif's metadata with matlab ?

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2 Answers

Answer by Geoffrey
on 22 Apr 2016

Well can you put a sample code please, I don't get it.
For instance if I want to add a Metadata field called 'IhateTiffFormat' and I want to put the value 'yes' inside. I tried:
tagperso.IhateTiffFormat = 'yes';
t.setTag(32770, tagperso);
And I get the error :
Error using tifflib
Tag number (32770) is unrecognized by the TIFF
library.
For creating IFD it's so badly explained in matlab help that I don't understand how to use it... Ther is no sample to see how to create one IFD? How to read a subIFD? How to add new tags in a IFD?

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Answer by Walter Roberson
on 21 Apr 2016

TIFF does not define its tags by name. TIFF tags are defined by numeric value, with any alphabetic name being for convenience.
To create a new tag, you will need to use TIFF settag() with a tag number 32768 or higher, and it being recommended to avoid the Adobe tags that have become effectively extensions. The alternative is to create a private IFD and put whatever tags one wants in there. What-ever you do you will need to coordinate with whatever has to read the file, since the names of the tags are not stored in the file.

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Geoffrey
on 21 Apr 2016
Thank's a lot I will try this !

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