# The Application of the Montage Image Mosaic Engine To The Visualization Of Astronomical Images

## TL;DR

The paper discusses how the Montage Image Mosaic Engine, originally designed for assembling astronomical images into mosaics, has been adapted for visualization purposes, including new tools and support for sky-tessellation schemes.

## Contribution

It introduces new visualization features in Montage, such as mViewer, and support for HEALPix and TOAST schemes, enhancing its utility for astronomical image visualization.

## Key findings

- mViewer enables complex multi-color image creation with a single command
- Montage now supports HEALPix and TOAST sky-tessellation schemes
- Visualization capabilities are integrated into the Montage toolkit for scalable systems

## Abstract

The Montage Image Mosaic Engine was designed as a scalable toolkit, written in C for performance and portability across *nix platforms, that assembles FITS images into mosaics. The code is freely available and has been widely used in the astronomy and IT communities for research, product generation and for developing next-generation cyber-infrastructure. Recently, it has begun to finding applicability in the field of visualization. This has come about because the toolkit design allows easy integration into scalable systems that process data for subsequent visualization in a browser or client. And it includes a visualization tool suitable for automation and for integration into Python: mViewer creates, with a single command, complex multi-color images overlaid with coordinate displays, labels, and observation footprints, and includes an adaptive image histogram equalization method that preserves the structure of a stretched image over its dynamic range. The Montage toolkit contains functionality originally developed to support the creation and management of mosaics but which also offers value to visualization: a background rectification algorithm that reveals the faint structure in an image; and tools for creating cutout and down-sampled versions of large images. Version 5 of Montage offers support for visualizing data written in HEALPix sky-tessellation scheme, and functionality for processing and organizing images to comply with the TOAST sky-tessellation scheme required for consumption by the World Wide Telescope (WWT). Four online tutorials enable readers to reproduce and extend all the visualizations presented in this paper.