commons-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Gary Lucas" <>
Subject [sanselan] Question about loading a partial image
Date Tue, 26 Jul 2011 12:44:14 GMT
I have a question about loading partial images using Sanselan.

I am using Sanselan to load and process GeoTIFF images and so far it works like a champ. 
 Unfortunately, some of the source files I'm using are quite large (12000x4000 pixels). When
I "zoom in" to the image, the part that I am showing on my display is often much smaller (1000x1000
pixels).   Is there a means to load up a partial image?  I would like to accomplish too goals:

a) Loading time is about 6 seconds, which is a long time for a user to have to wait.  It would
be nice to load a partial image and save loading time.

b) The buffered image produced by Sanselan when loading the file uses one 4-byte int per pixel,
which is really convenient for my processing, but has the consequence that the memory use
for the raw pixels is about 183 meg.  Loading a partial would reduce this.

The other thing I'm looking at is cases where I am "zoomed out".  It would be useful to copy
the raw image to a reduced size using image processing built into Sanselan.  Do you have a
code sample that shows how to do that.


Computer Programming is the Art of the Possible
Gary W. Lucas
Sonalysts, Inc.
215 Parkway North
Waterford, CT 06385
41-22-12.35 N / 72-10-07.54 E  (USNG/MGRS:  43T BF 63213 83711)

To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message