Sudden problem with TIF

pdxrjt · Post by **pdxrjt** » Tue Dec 02, 2008 6:46 am

I shoot in Sony A350 RAW format. I recently upgraded to XII Ultimate so I could use this format with PSP. I am putting together a series of pics and converting them to tif so I can work with them etc. I saved about 40 from RAW to Tif. Well, I did about 10 this morning and 1) The thumbnails in the folder are essentially grey; 2) they open correctly in PSP and will resave properly as jpeg etc.; 3) they do not open properly in other programs....although the original 40 did. (Other data--I can continue to open Sony RAW files in PSP and save them correctly.)

What happened? It was working fine and now..... grey squares?

Any thoughts or suggestions would be appreciated.

TIA

Tim Morrison · Post by **Tim Morrison** » Wed Dec 03, 2008 2:06 pm

Would it be possible to post a sample of one of those misbehaving TIFs to a website somewhere?

pdxrjt · Post by **pdxrjt** » Thu Dec 04, 2008 2:31 am

Well, I certainly have about 10 of them.... (also sent an e-mail to corel about it... waiting for a reply.) Unfortunately, I haven't generally posted things on the web for public consumption.... if someone can tell me a good place to do it, I would be happy to.

Tim Morrison · Post by **Tim Morrison** » Fri Dec 05, 2008 3:16 am

You could upload it to a free file storage site, Like MediaFire (http://www.mediafire.com/), then post the link here.

pdxrjt · Post by **pdxrjt** » Fri Dec 05, 2008 3:18 am

Will do..... am very tied up today and tomorrow, but will post a link on Sat. Sorry for the delay, but REALLY appreciate the help!!

pdxrjt · Post by **pdxrjt** » Sat Dec 06, 2008 6:39 pm

Okay, thanks for the tip on the website.
If I did this correctly, here is the photo:
http://www.mediafire.com/?wkowzg3jjwi
I don't really see how to post it as a pic though... sorry

It was a raw...opened fine in PSP 12 Ulti. I saved as a tif, yet the thumbs look ... well, like this. It opens fine in PSP. I can open it and save it in another program... and the thumbs look fine.
TIA

Tim Morrison · Post by **Tim Morrison** » Sun Dec 07, 2008 4:00 am

This is a problem that occurs with 16 bit/channel (48bit) TIF files that are saved with LZW compression. I think it may have something to do with PSP not saving metadata, like EXIF and an embedded thumbnail, in LZW compressed TIFs. Most programs don't. Some programs then have trouble making a proper thumbnail... Windows Explorer and PSP in particular. Photoshop does embed metadata in LZW compressed TIFs, including a JPG thumbnail, so this problem doesn't happen with those files.
Although I have found programs that have trouble displaying a proper thumbnail, I haven't found any that can't open the image.
The best way to solve the problem is to click the "Options" button on the Save dialogue box, and change the compression type to "Uncompressed".
This has a couple of other advantages. Your EXIF data will be preserved, and the file size will be smaller.
It might seem strange that an uncompressed TIF is smaller than a compressed one, but this only happens for 16 bit/channel TIFs. In the 16 bits of data there are only 11 or 12 bits of image data and 4 or 5 bits of noise. This noise prevents LZW compression from being able to compress the data. LZW compression works fine on 8 bit/channel images, but not on 16 bit/channel images.
For example, if I take your London_01.tif image and resave it as both 16 and 8 bit/channel, and both LZW compressed and uncompressed TIFs, I get the following file sizes -
16 bit/channel, LZW compressed - 88.9 MB
16 bit/channel, uncompressed - 80.7 MB
8 bit/channel, LZW compressed - 22.8 MB
8 bit/channel, uncompressed - 40.4 MB.

You can use File > Batch Process to convert the problem TIFs to uncompressed copies. Make sure to click the "Options" button and select "Uncompressed".

pdxrjt · Post by **pdxrjt** » Sun Dec 07, 2008 7:49 am

Tim, that was it.... worked like a charm.

Many thanks!

ps I never would have guessed it was anything like that