Make VisIt perform better for opening large images.

[aowen87]

A couple of LLNL users want to look at experimental results in VisIt and this means reading large images. However, the users are concatenating these images together into larger "filmstrip" images and then opening the larger images in VisIt. The images are about 60K*1K pixels and VisIt is not particularly good at images in the first place. The users complain of bad performance. There are some things we can do to improve our image performance:1. Serve up data in uchar so we don't bloat memory2. Enhance filters along the way to Pseudocolor, Truecolor plots so the can all handle at least uchar data.3. Enhance Lineout so it can deal with image's uchar data if it does not already. The users asked for lineout.4. Enhance rectilinear grid rendering so it draws images as single textured quad or set of smaller textured quads.

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Ticket number: 897 Status: Pending Project: VisIt Tracker: Bug Priority: Normal Subject: Make VisIt perform better for opening large images. Assigned to: Brad Whitlock Category: - Target version: - Author: Brad Whitlock Start: 11/18/2011 Due date: % Done: 50% Estimated time: Created: 11/18/2011 02:04 pm Updated: 04/04/2012 11:24 am Likelihood: 3 - Occasional Severity: 2 - Minor Irritation Found in version: 2.3.2 Impact: Expected Use: OS: All Support Group: Any Description: A couple of LLNL users want to look at experimental results in VisIt and this means reading large images. However, the users are concatenating these images together into larger "filmstrip" images and then opening the larger images in VisIt. The images are about 60K*1K pixels and VisIt is not particularly good at images in the first place. The users complain of bad performance. There are some things we can do to improve our image performance:1. Serve up data in uchar so we don't bloat memory2. Enhance filters along the way to Pseudocolor, Truecolor plots so the can all handle at least uchar data.3. Enhance Lineout so it can deal with image's uchar data if it does not already. The users asked for lineout.4. Enhance rectilinear grid rendering so it draws images as single textured quad or set of smaller textured quads.

Comments: I have a branch called ImageOptimizations where these features are largely underway. I have the image reader improved, certain filters passing through uchar data, and a single textured quad renderer. I still need to resolve some issues in the renderer and make sure that it works well with the largest image sizes.