Re: slow 2d image generation

• To: Jim Cookas <James.M.Cookas@xxxxxxxx>
• Subject: Re: slow 2d image generation
• From: Jim Koutsovasilis <jimk@xxxxxxxxxx>
• Date: Tue, 6 Jan 2004 09:45:49 +1100

Hello Jim,

if you are using a DisplayImplJ2D display, try a DisplayImplJ3D instead.
It might be faster.

Regards,
Jim.
---
Jim Koutsovasilis
Bureau of Meteorology, Australia
jimk@xxxxxxxxxx

On Mon, Jan 05, 2004 at 04:24:52PM -0600, Jim Cookas wrote:
> hello group
> 
> first off, many thanks to all who helped with my previous question regarding 
> constant maps...however, i now have a new problem...
> 
> the application i am currently developing with visad has a feature to load 
> and display 2d image data from an ascii file...i am using the textadapter 
> class to read the file and turn into a flatfield...the ascii file is in the 
> tab-spaced format that the textadapter class can read....here is a snip of 
> the first five lines of an example ascii file:
> 
> <snip>
> (Down_Range,Cross_Range)->(RCS)               
> Down_Range    Cross_Range     RCS
> -755.383      -755.383        -124.0984508
> -731.684      -755.383        -124.0586397
> -707.986      -755.383        -123.995843
> -684.288      -755.383        -123.9096856
> 
> ...and so on
> </snip>
> 
> in this case, 'down_range' maps to the x-axis, 'cross_range' maps to the 
> y-axis, and 'rcs' maps to an rgb value...everything loads and displays fine, 
> but there are three major problems:
> 
> 1) loading the data is ___sloooow___...the example file i snipped above comes 
> to 147515 bytes (256 x 256 image size) and it takes a solid 30 seconds from 
> when the file is opened to when the image is finally displayed...we have c++ 
> code in other applications that loads and displays the same data almost 
> instantly...is it a java problem?...is it visad?...is it something i'm doing 
> wrong?
> 
> 2) panning and zooming of the image (and line plots for that matter) are slow 
> and choppy...when data is rendered as points, these functions are very quick, 
> smooth, and acceptable...is there any way to speed up panning/zooming?
> 
> 3) is there any way to increase the resolution of the image rendering to make 
> it more 'smooth'?...right now it looks textured...when zoomed in closely, the 
> data points look very triangular...any ideas?
> 
> thanks in advance for any help that can be provided...let me know if you need 
> more information from me...peace!
> 
> jc
> 

• References:
  • slow 2d image generation
    • From: Jim Cookas