Thread Subject: using image to display a large matrix and then zoom in

Hello
I have a result, that I'd like to display as using IMAGE.
The size of the result is something like 10000 times 20000 points so I can not use it directly. (Java is just dying)

So I interpolate down the result to 500 times 1000 points, which I can display without problems using IMAGE. I can of course also zoom in. But I'd like to have a function, that by zooming there is a new interpolation over the result made, so that I can also see details in the result.

I mean if java would be capable to display the 10000 times 20000 matrix, then I could zoom in end see the single data point. But if I zoom in the downsampled matrix I see only downsampled data.

So, how can i solve this problem ?

"Heinz " <heinz.widmer@ch.schindler.com> wrote in message
news:hnvrl1$qgb$1@fred.mathworks.com...
> Hello I have a result, that I'd like to display as using IMAGE.
> The size of the result is something like 10000 times 20000 points so I
> can not use it directly. (Java is just dying)
>
> So I interpolate down the result to 500 times 1000 points, which I can
> display without problems using IMAGE. I can of course also zoom in.
> But I'd like to have a function, that by zooming there is a new
> interpolation over the result made, so that I can also see details in the
> result.
> I mean if java would be capable to display the 10000 times 20000 matrix,
> then I could zoom in end see the single data point. But if I zoom in the
> downsampled matrix I see only downsampled data.
> So, how can i solve this problem ?

Create a zoom mode object using ZOOM and set its ActionPostCallback to a
function that performs the appropriate interpolation/resampling and updates
the image's data (specifically the XData, YData, and CData properties.

http://www.mathworks.com/access/helpdesk/help/techdoc/ref/zoom.html

--
Steve Lord
slord@mathworks.com
comp.soft-sys.matlab (CSSM) FAQ: http://matlabwiki.mathworks.com/MATLAB_FAQ

On 19 Mar, 13:45, "Heinz " <heinz.wid...@ch.schindler.com> wrote:
> Hello
> I have a result, that I'd like to display as using IMAGE.
> The size of the result is something like 10000 times 20000 points  so I can not use it directly.    (Java is just dying)
>
> So I interpolate down the result to 500 times 1000 points, which I can display without problems using IMAGE.      I can of course also zoom in.  But I'd like to have a function, that by zooming there is a new interpolation over the result made, so that I can also see details in the result.
>
> I mean if java would be capable to display the 10000 times 20000 matrix, then I could zoom in end see the single data point.  But if I zoom in the downsampled matrix I see only downsampled data.
>
> So, how can i solve this problem ?

Don't know how to solve this, but it is a standard problem
when displaying large amounts of data, e.g. in Google Earth:
You start with an overview that show large areas in coarse
details, and replace it by smaller areas with higher details
as you zoom in. It's technically *very* demanting to implement
that kind of stuff, particularly if you want it to respond fast.

Look for multiresolution image browsers, e.g. for satellite
images. That kind of stuff might even exist for matlab.

Rune

On Fri, 19 Mar 2010 08:45:21 -0400, Heinz <heinz.widmer@ch.schindler.com>
wrote:

> Hello I have a result, that I'd like to display as using IMAGE.
> The size of the result is something like 10000 times 20000 points so I
> can not use it directly. (Java is just dying)
>
> So I interpolate down the result to 500 times 1000 points, which I can
> display without problems using IMAGE. I can of course also zoom
> in. But I'd like to have a function, that by zooming there is a new
> interpolation over the result made, so that I can also see details in
> the result. I mean if java would be capable to display the 10000 times
> 20000 matrix, then I could zoom in end see the single data point. But
> if I zoom in the downsampled matrix I see only downsampled data. So, how
> can i solve this problem ?

Maybe this can be of use if you have the Image Processing Toolbox:
http://www.mathworks.com/access/helpdesk/help/toolbox/images/br0xjyx-1.html

It will be a bit roundabout for your particular use case: It currently
supports Tiff files. But it looks like you are able to read the data in,
so maybe you can write it out as a Tiff file? then create an rset file and
then.. use IMTOOL.