Preparing Red‐Green‐Blue Images from CCD Data

By Robert Lupton, M. Blanton, G. Fekete, David W. Hogg, W. O'Mullane, A. Szalay, N. Wherry. 2003

289 citations recorded by the source corpus.

We present a new, and we believe arguably correct, algorithm for producing red‐green‐blue (RGB) composites from three‐band astronomical images. Our method ensures that an object with a specified astronomical color (e.g., g−r and r−i) has a unique color in the RGB image, as opposed to the burnt‐out white stars to which we are accustomed. A natural consequence of this is that we can use the same colors to code color‐magnitude diagrams, providing a natural “index” to our images. We also introduce the use of an arcsinh stretch that allows us to show faint objects while simultaneously preserving the structure of brighter objects in the field, such as the spiral arms of large galaxies. We believe that in addition to their aesthetic value, our images convey far more information than do the traditional ones, and we provide examples from Sloan Digital Sky Survey (SDSS) imaging, the Hubble Deep Field (HDF), and Chandra to support our claims.

Subfields: Computer Vision and Pattern Recognition, Ecology, Ocean Engineering

View Paper: https://www.semanticscholar.org/paper/9452d677e3f101fa79616da959feeb98a9ef34f9

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Citations in the corpus

The eagle simulations of galaxy formation: Public release of halo and galaxy catalogues (2015, methodology): “The threecolour gri images are prepared from the virtual skirt observations adopting the method of Lupton et al. (2004).”
The GALEX Ultraviolet Atlas of Nearby Galaxies (2006, methodology): “The images used are ‘‘asinh’’ scaling versions (Lupton et al. 2004) of the 2 pixel smoothed FUV image (blue), the original NUV image (red ), and a linear combination of the two (green).”
THE TENTH DATA RELEASE OF THE SLOAN DIGITAL SKY SURVEY: FIRST SPECTROSCOPIC DATA FROM THE SDSS-III APACHE POINT OBSERVATORY GALACTIC EVOLUTION EXPERIMENT (2013, methodology): “Color images of regions of the sky in JPEG format (based on the g, r and i images; see Lupton et al. 2004) can be viewed in a web browser with the SkyServer Navigate tool.”
The ATLAS3D project - II. Morphologies, kinemetric features and alignment between photometric and kinematic axes of early-type galaxies (2011, methodology): “Our morphological characterization is purely visual, based on SDSS and INT r-band images as well as the SDSS true colour (red–green– blue) images (Lupton et al. 2004) when available, but we do not C© 2011 The Authors, MNRAS 414, 2923–2949 Monthly Notices of the Royal Astronomical Society C© 2011…”
Galaxy Zoo 2: detailed morphological classifications for 304,122 galaxies from the Sloan Digital Sky Survey (2013, methodology): “Frames were combined using Montage (Jacob et al. 2010) and converted to a colour image using a slightly modified version of the SkyServer asinh stretch code (Lupton et al. 2004), with parameters adjusted to replicate the normal SDSS colour balance.”
NIHAO project – I. Reproducing the inefficiency of galaxy formation across cosmic time with a large sample of cosmological hydrodynamical simulations (2015, methodology): “The image brightness and contrast are scaled using arcsinh as described in Lupton et al. (2004).”
The ATLAS3D project – I. A volume-limited sample of 260 nearby early-type galaxies: science goals and selection criteria (2010, methodology): “Our morphological selection was done by visual inspection of the true-colour red-green-blue images (Lupton et al. 2004) provided by the SDSS DR7 which are available for 82% of the galaxies in the parent sample.”
Galaxy Zoo: 'Hanny's Voorwerp', a quasar light echo? (2009, methodology): “We show each of the five SDSS images (u, g, r , i and z) separately as well as a three-colour gri composite (Lupton et al. 2004).”
Galaxy Zoo: morphologies derived from visual inspection of galaxies from the Sloan Digital Sky Survey (2008, background): “All objects in this sample which the SDSS photometric pipeline (Lupton et al. 2004) identified as a galaxy were included in the Galaxy Zoo data base, regardless of whether or not such spectra have been obtained to date.”