Adding Tags to TIF Files Reduces File Size

1

I've recently begun scanning all of the pictures in my family's archive. I'm using a Canon LiDE 400 to scan the pictures at 600 dpi directly into a TIF file, and I'm using Windows 8.1.

The issue I'm having is that when I enter metadata tags to the files in the Windows properties box, the file size is being drastically reduced. I understand that TIF is a lossless format, so editing the metadata shouldn't cause data loss, correct? I'm concerned about the possibility of losing data within the picture. My understanding is that that shouldn't be possible though.

Can anyone explain this loss of file size? Am I misunderstanding the properties of TIF files? Below is a screenshot showing the reduced file sizes. The only difference between the files is the one on the right has tags added to it.

enter image description here

seanr

Posted 2020-01-20T07:05:33.330

Reputation: 111

TIFF isn't exclusively lossless. It just happens to support lossless compression too and is widely used. However, TIFF can be lossy if the user wants it to be. Please provide the tags you added – Pradyoth Shandilya – 2020-01-20T09:02:30.963

Answers

1

TIF supports lossless RLE compression, amongst others, and it is possible that the Windows software responsible for modifying metadata has to load the entire image in to modify it and has compression enabled by default.

Other lossless compressors might be supported, as well as lossy JPEG compression in the TIFF format.

In order to detect what compression was used you might be interested in the SuperUser question Determining the image compression algorithm used on TIFF images

Mokubai

Posted 2020-01-20T07:05:33.330

Reputation: 64 434

1This is the correct answer. I edited the metadata of an uncompressed TIFF file through the Windows->Properties and the resulting TIFF file was LZW compressed. – StarGeek – 2020-01-20T17:22:10.890

Asked: 2020-01-20T07:05:33.330

Viewed: 46 times

Active: 2020-01-20T09:02:08.743