[OpenLayers-Users] "progressive jpegs" as tiles not loading gracefully

[Steve Guerrero]

Hi all,

I am using openlayers to navigate large tiled microscopy images in 
"progressive jpeg" format.  I'm using the TMS layer and my own getURL 
function to retrieve tiles.

Progressive jpegs are the kind that first load a blocky/blurry low 
resolution version of the image and then get progressively more detailed.

When I have a tiled image with smooth backgrounds and/or very little 
image detail within the tiles (i.e. the jpegs are highly compressed, the 
file sizes are pretty small), they load just fine.  But when I try a 
tiled image with lots of small details (i.e. less compression, bigger 
jpeg filesizes), they seem to be "stuck" either partially loaded (strips 
of white empty space) or they are only loaded at low resolution 
(blocky/blurry first pass of the progressive jpeg).

My question is, is there a way to force that the tile should be loaded 
completely to its highest resolution (i.e. don't bother showing 
intermediate resolutions, just wait until you have the full res jpeg). 
Is this a timeout issue with tile loading?  Is there some way I can 
instruct OpenLayers to spend more time loading each tile so that it 
arrives complete?

Thanks,
-sg