Monday, July 02, 2007

More JP2 tests

Following last week's tests I've encoded a representative set of images at various JP2 compressions. Download Excel spreadsheet showing file sizes & URLs to images.

8 Comments:

At 3:03 AM, Blogger pk said...

Whoops. Didn't see this entry before commenting in the last one.

I'm a bit amazed actually. I feel sure on a pepsi/coke test I would get 100%, but I have to (grudgingly, as it goes against my natural logic) admit that I couldn't identify much of a difference on the samples I looked at between the 100 and the 50s.

I looked at the line drawing, betterlight, colour illustr and one of the specimens. (I just looked at the 100 and the 50 and compared for all magnifications).

It's a bit difficult giving an opinion in a way, not knowing what you are aiming at here -- part of me as I say, logically wants to kneejerk advocate vociferously for retaining the highest quality/highest resolution images. But my experience (and I'm pretty sure that I'd be among the higher users' end of botanicus) is slightly tainted by what I feel are poor quality images available for download. I presume that's for a reason and that the cream is saved for the viewer browser thingy.

But anyway, yeah....my true opinion in relation to the xls is that it does in fact look like, for the illustrations anyway, that the half-quality images are not discernibly different from the 100s. I am only one person though and am not regarded as a useful sample space!

 
At 9:31 AM, Blogger Chris Freeland said...

PK - Thanks for your note. The issue with the lower quality images for download is one of outbound bandwidth. We are upgrading to Internet2, and once that switch takes places we'll be making the high quality images available for download. Just to put a finer point on it, we still have the 100% TIFs on the server so we can always go back and reencode at various levels & formats in the future.

 
At 10:50 AM, Blogger pk said...

Thanks Chris. Is the switcheroo to internet2 happening this year or..?

 
At 3:52 PM, Blogger Chris Freeland said...

Yes, we've petitioned to join our local I2 consortium and have begun talks with our carriers to price out cabling. We have budget for it, so it's really just a matter of getting contracts worked out, etc. I certainly hope it's resolved by the end of the year!

 
At 10:24 AM, Blogger peacay said...

--I certainly hope it's resolved by the end of the year!--

Is this still looking likely??

(I have been sitting on my hands patiently watching and whistling, waiting to hear news)

 
At 10:26 AM, Blogger Chris Freeland said...

Yes, seems like we will be making a major upgrade to our outbound bandwidth by the end of the year, maybe as late as early next year. You are not alone in wanting access to the higher resolution files, and we hope to make them available soon!

 
At 9:08 PM, Blogger Sune said...

The full size jp2 research images downloaded with Explorer have been OK, but NOT better than the Mr.SID images that sometimes have been available from your server. One problem has been the size 80-90Mb probably because Explorer convert them to something else. With a Mr.SID plugin to PhotoShop I get a much faster download and as far that I can see, the same result.

 
At 11:09 AM, Blogger Mike said...

Well done job. I just downloaded excel sheet shared by you and got answers of my all questions. Thanks Chris. I hope that other problems will also be resolved by the end of the year.
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