Feature Request : Pyramid TIFFs – Tiled TIFFs

KO
Posted By
Kristian_Ottosen
May 4, 2004
Views
1101
Replies
7
Status
Closed
Hi,

This is mostly for the Photoshop Developers I guess – but I was told to post feature requests here by an Adobe employee.

Photoshop 6,7 and CS’s ability to write TIFF files with embedded image pyramid is great when preparing images for use with a Dynamic Imaging Server.

But while working with very large images like the 2.6 Giga byte image online here <http://www.yawah.com/bluemarble.html> I have stumbled over a few limitations.

1) I found that Photoshop never writes more than 4 resolution levels to the files. The above mentioned image requres 8 resolution levels (40000 by 20000 pixels). This greatly impacts the performance of the server when working at lower resolutions. Is this a bug?

2) Organising TIFF images as "tiles" instead of "strips" can greatly improve performace when zooming at high resolution. Photoshop reads tiled TIFFs OK, so my feature request is this: Please make it possible to write tiled TIFFs as well (preferably with user defined tile dimansion).

Thanks in advance
Kristian

<http://www.yawah.com>
Related Tags
feature request tiff tile

How to Master Sharpening in Photoshop

Give your photos a professional finish with sharpening in Photoshop. Learn to enhance details, create contrast, and prepare your images for print, web, and social media.

CC
Chris_Cox
May 5, 2004
The pyramid levels written will depend on how many pyramid levels you specified in preferences.

User defined tile sizes could be messy. But how about Photoshop using fixed size tiles (256×256 or so), or it’s own tile sizes (which will vary with available memory)?

Also, do realize that compression will be worse if we save as tiles.

And I’ll have to check on compatibility with tiled images — last time I checked, many applicaitons couldn’t read tiled TIFF images correctly.
CC
Chris_Cox
May 5, 2004
BTW – there is a sub forum for feature requests (so they don’t get lost)
KO
Kristian_Ottosen
May 5, 2004
Hi Chris,
´
I didn’t notice the "feature request" forum until after i posted my message. Sorry.

I just can’t seem to find the preferences for "pyramid levels" in Photoshop CS. Is it just me being blind or are you talking about a future version of Photoshop? Normally I would expect the number of pyramid levels to be calculated based on the size of the image so that the smallest resolution is something like a 128 x 128 thumbnail.

I agree that user defined tile sizes could be messy. 512×512 tiles might be a good choice for today’s hardware.

I don’t agree with you that compression will be worse when organising images as tiles instead of strips. The 40000 x 20000 image mentioned in my previous post takes up 1.15 GB when saved as a tiled, ZIP compressed pyramid with 4 resolution levels by Photoshop CS (1.27 GB using LZW). Photoshop CS won’t save it with JPEG compression (the strips are probably to wide for JPEG – another feature request).
For this project we had to write our own TIFF encoder and the reeulting ZIP compressed, tiled TIFF with 8 resolution levels takes up 1.12 GB. So it is actually slightly smaller than the tiled one – even with 4 extra resolution levels.
A high quality JPEG’ed version is just 505 MB – and since JPEG compression by nature uses tiles internally, my guess would be that the file size would increase when using strips instead of tiles.

With regards to compatibility, couldn’t you display a warning to the user in the same way that the user is warned about using ZIP and JPEG compression? When Adobe first added the ZIP and JPEG compression schemes to Photoshop very few application could read the files. But when you add something to Photoshop it seems to catch on to other applications pretty fast. Some of us need thos tiles.. Please…

Best Regards
Kristian
MV
Mathias_Vejerslev
May 5, 2004
Hej Kristian,

As a fellow dane, I´d just like to say: Interesting products/demos you have there! As a production graphic artist, I really like your ‘pull’ strategies.

MVH
Mathias
CC
Chris_Cox
May 6, 2004
Kristian – in preferences, under "image cache".

JPEG has a 64k x 64k hard limit on image sizes. Yes, the Photoshop JPEG implementation has a 32k x 32k limit — and it’s on the list of things to fix.

Your smaller size could come from removing metadata, or from using a higher compression setting in the ZLIB code (Photoshop uses effort level 6 by default).

In theory, the tiled representation will have greater overhead (just to store the tile offsets, tile lengths, indicate start of ZLIB block, etc.), and not get as much compression (because there is less data to refer back to).

JPEG compressing tiles will still be larger – because there is overhead associated with JPEG compression.

Also, how many users need tiled TIFF images? I would have to justify the work to my managers. (and saying: "well, it gets us one extra upgrade" doesn’t fly too well with them)
KO
Kristian_Ottosen
May 7, 2004
Hi Chris,

Thanks for the tip with the "Image Cache".

The smaller file size is not due to removal of metadata, bit could very well be caused by different compression settings.

Photoshop stores the 43200 by 21600 pixel image as 2700 strips of 43200 x 8 pixels (1 Mb each). Using tiles of 512 by 512 pixels (768 Kb each) requires 3655 tiles. That is 955 extra offsets and lengths to store within the file which takes up less than 8 Kb. So the overhead and extra file size is minimal.

Its hard to tell how many users will benefit from tiled TIFF images. I believe all applications which can use multi resolution TIFF files will perform much better when using a tiled layout and it is probably something that you could implement in a few hours. It’s dead simple.

Well, I made my wish and will wait patiently until Christmas 😉
CC
Chris_Cox
May 7, 2004
Hmm – We should have gone for longer strips than that.

(and it’s not as simple as it sounds to implement – and the testing will take longer than implementation)

MacBook Pro 16” Mockups 🔥

– in 4 materials (clay versions included)

– 12 scenes

– 48 MacBook Pro 16″ mockups

– 6000 x 4500 px

Related Discussion Topics

Nice and short text about related topics in discussion sections