Copy link to clipboard
Copied
Jorma Jokinen.
I have made a Family Tree chart in tiff format. Every time I get new information I open it in PS and do my editing. After repeating this tens of times the older parts of the chart are beginnig to seem more and more unreadable. Why this because tiff format is told to be uncompressed and loseless.
Copy link to clipboard
Copied
This was, in my opinion (and I am not the only one), a huge mistake by those who maintained the TIFF standard. What you get is a TIFF document containing JPEG compression. The compression and the file format are not the same thing; that's why we can have JPEG inside a PDF, for instance. It is one of many compressions available in writing TIFF, for example run-length, LZW, ZIP. JPEG compression, however it is used, is lossy and causes damage. Hence my question to JJo-45, whether this option was used.
Copy link to clipboard
Copied
Those that maintained the TIFF standard: Adobe. It's theirs.
And just like DNG, we can embed a JPEG in that container.
Copy link to clipboard
Copied
Indeed, Adobe maintained it (though they included and standarised work by others). When introduced to the standard it was puzzling. Many years later, it appeared unexpectedly in Photoshop.
Copy link to clipboard
Copied
It seems to me that the problem is not related to the image format.
Your example looks like you first reduced the size of the entire image (or an individual layer) and then increased it. For example, I took your screenshot with good readable text, its size 576x801 px reduced it to 200x308 px, and then returned it to its original size using Preserve Details interpolation algorithm (Photoshop uses it automatically if you did not change the interpolation settings) . It can be seen that very similar distortions of letters to images have occurred (the difference is only in sharpness, I assume that you added it later).
Copy link to clipboard
Copied
"I open a picture in PS, edit it and save in tiff format in mode without any compression. Why it is not exatly the same picture that I had on the screen when I open it again? "
I think the results shown from your screen shots are clear. It is not the editing and saving of TIFF which causes the slow damage to the picture. You could open and save a TIFF a million or a billion times without any damage. The damage is, therefore, caused by the things you do when you're editing (not necessarily every time).