DOI: 10.5061/dryad.pj073
title: Data from: Image Calibration and Analysis Toolbox – a free software suite for measuring reflectance, colour, and pattern objectively and to animal vision

description: 1. Quantitative measurements of colour, pattern, and morphology are vital
 to a growing range of disciplines. Digital cameras are readily available
 and already widely used for making these measurements, having numerous
 advantages over other techniques, such as spectrometry. However,
 off-the-shelf consumer cameras are designed to produce images for human
 viewing, meaning that their uncalibrated photographs cannot be used for
 making reliable, quantitative measurements. Many studies still fail to
 appreciate this, and of those scientists who are aware of such issues,
 many are hindered by a lack usable tools for making objective measurements
 from photographs. 2. We have developed an image processing toolbox that
 generates images that are linear with respect to radiance from the RAW
 files of numerous camera brands, and can combine image channels from
 multispectral cameras, including additional ultraviolet photographs.
 Images are then normalised using one or more grey standards to control for
 lighting conditions. This enables objective measures of reflectance and
 colour using a wide range of consumer cameras. Furthermore, if the
 camera's spectral sensitivities are known, the software can convert
 images to correspond to the visual system (cone-catch values) of a wide
 range of animals, enabling human and non-human visual systems to be
 modelled. The toolbox also provides image analysis tools that can extract
 luminance (lightness), colour, and pattern information. Furthermore, all
 processing is performed on 32-bit floating point images rather than
 commonly used 8-bit images. This increases precision and reduces the
 likelihood of data loss through rounding error or saturation of pixels,
 while also facilitating the measurement of objects with shiny or
 fluorescent properties. 3. All cameras tested using this software were
 found to demonstrate a linear response within each image and across a
 range of exposure times. Cone-catch mapping functions were highly robust,
 converting images to several animal visual systems and yielding data that
 agreed closely with spectrometer-based estimates. 4. Our imaging toolbox
 is freely available as an addition to the open source ImageJ software. We
 believe that it will considerably enhance the appropriate use of digital
 cameras across multiple areas of biology, in particular researchers aiming
 to quantify animal and plant visual signals.
description: Linearisation
 DataMeasurements of grey
 standards taken by cameras and spectroradiometers to determine how linear
 the camera response is.Cone Catch Colour
 Testing PhotosPhotographs of colour
 samples (colour pastels) of known reflectance used to compare spectrometer
 and camera cone-catch estimates between cameras and spectrometer. .mspec
 files are included for compatibility with the image analysis
 toolbox.Pastel Reflectance
 SpectraReflectance spectra of
 the colour pastels used as colour samples.Image Analysis Toolbox
 user guideThis is the original
 user guide that may become obsolete as the toolbox is improved. Please see
 www.jolyon.co.uk or www.sensoryecology.com for the latest
 version.micaToolbox_User_Guide_V1.0.pdf