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NAC-Slide: Displaying Very Large NAC ImagesRobert WagnerMentor: Mark Robinson

School of Earth and Space Exploration, ASU17 April 2010

NAC-Slide Overview

Objective was to display the very large LROC Narrow Angle Camera images at full resolution.

Initial goal was to display NAC images on the LROC Science Operations Center’s Tile Wall.

Developed “NAC-Slide”: Automatically scrolls through LROC NAC images.

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LROC Narrow Angle Camera

Two high-resolution cameras 12-bit grayscale images 5064 pixels per line Usually 52224 lines Nominal resolution:

50cm/pixel Footprint:2.5km by 25km

With paired images, 5km by 25km footprint3

The Tile Wall

3x3 grid of high-resolution monitors Total size approximately 7500x6000 pixels Runs on Ubuntu Linux

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LROC Science Operations Center

Displaying Large Images

A standard 1024x768 monitor can only display 0.3% of a NAC image at full resolution.

Even the Tile Wall can only display 10% of a NAC image at full resolution.

Solution: Scroll vertically down the image. Works on Tile Wall, which can display the

full width of a NAC image Not so good for personal computers

NAC left NAC right

NAC-Slide Design

Four elements Full-resolution view Overview map Histogram Image information

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HistogramShows the

distribution of pixel values in the image.

Allows science team to easily assess validity of camera settings for the image.

Overview MapShows entire

image, and location of the main viewpoint.

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Information WindowShows location, size,

and capture date of image.

Lists major nearby features, based on a database of feature names and locations.

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Implementation

Developed in C Command-line driven, with optional parameters

Image list, scroll speed, etc. Used X Windows library for interface

Cross-platform (Linux, Mac OS) Challenges:

Reading NAC image formats Good automated stretch from 12-bit to 8-bit Readable text on huge screens

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Results and Future Work

NAC Slide on the Tile Wall gives the scientists in the control room near-real-time feedback on what the NAC images actually look like.

Current goal: Create a NAC image viewer that works well on small monitors, for quickly looking through images at full resolution. Steps across an image, one screen-full at a time First version is mostly complete

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Questions?

NAC image M104227032L