[udig-devel] GeoTiff Zoom -- A slick feature is marred by a glitch

[Jesse Eichar]

You are quite right and this is one of the fixes I want for RC7 but  
might not make it until 1.1 Depending on what other critical bugs I  
have to fix.  Currently it is on the RC7 release schedule.

Jesse


On 1-Dec-06, at 1:28 PM, Gary Lucas wrote:

>
> I've observed a glitch in the zoom function when working with
> GeoTiffs that marrs what would otherwise be a pretty
> slick implementation in uDig 1.1.RC6a
>
> I was given a somewhat large (25 Meg) Tiff image
> with a high level of detail and asked to plot it.
> Because the size of the image was so much larger than the
> screen, it was initially shown at much less than its full
> resolution.  Intending to observe a finer level of detail,
> I pressed the magnifying glass icon a few times in rapid
> succession to zoom in.  As I did, uDig
> immediately responded with a "zoomed" image by blooming
> the pixels.  When I stopped clicking, there was a pause and
> then the correctly rendered image (with a higher resolution)
> popped in.
>
> I say that this WOULD have been a very slick implementation
> (and an idea I intend to copy for my own applications in the future)
> had it not been for a glitch.  For whatever
> reason, while rendering the zoomed image, the map view
> was blanked out and filled with white. Since this process
> took a few seconds, it was rather distracting. But, worse, it
> spoiled what would have been a very nice effect.
>
> Anyway I do admire what the uDig developers were able to
> accomplish, and I hope that you can correct this glitch in
> some future release because it would really make for a nice
> feature.
>
>
> -----
>
> On a related note, I must add that I'm not really sure that the
> image I have is a proper GeoTiff...  I think it might actually be
> a ESRI World format (related to the GeoTools WorldImageReader class).
> While that might have some bearing on the problem, the real issue
> here is that it is often very difficult to figure out what
> is going on with uDig.  For example, when I first tried to load the  
> tiff
> it just wouldn't show up. I imported it into the Catalog, tried to add
> it to a new map, and got an empty view for my troubles.  I tried it a
> couple more times and finally, for reasons that escape me, it  
> showed up.
> It's worked everytime since.  I'm a bit worried about that because  
> I have
> no idea why it works now or what I will do if it ever stops working.
>
> What I see missing in uDig in general is a set of clear signals to the
> user as to what is going on and how to proceed with performing
> basic tasks. For example, when data doesn't plot, it would be nice
> to know why not. Because the application is so new, I'm sure that this
> is not entire unexpected. Still I think that the user's experience
> of flow of operations through the session is something that could
> stand more attention.
>
> Also, I still can't combine the Tiff image with any geo-referenced
> data from other sources. As I said, I suspect that my subject data is
> not a proper GeoTiff (there is a .tfw file that came with it). I'll  
> figure
> it out eventually...  But what's lacking here are some diagnostics  
> that
> would help the user. Ideally, when I hit across a "gumption trap" of
> this sort, I'd like to have some way of obtaining details on the
> data to see what's gone wrong. Perhaps something so simply as a
> "properties" menu to tell me what kind of data I'm looking at.
> Maybe you, the uDig developers, have ways of knowing why something
> doesn't plot, but at least this particular user does not.
> The information in the Operations/Layer Summary and
> Operations/Resource Summary may be a start in the right direction
> but I'm not sure what the information currently presented really
> tells me.
>
>
> Finally I want to say that I truly hope that uDig will become
> a very successful application. And I think that there is a danger
> that this lack of communicativeness on the part of the application
> is going to hamper its effectiveness every bit as much as any
> perceived lack of features.  So I hope readers of this note
> will take my remarks in the proper light
>
> Gary
>
>
>
>
>
> ---
> Gary W. Lucas, Senior Software Engineer
> Sonalysts, Inc
> 215 Parkway North
> Waterford, CT 06320
> (860) 326-3682
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