Image attributes:
img.date - creation date & time (text)
img.expprog - exposure program
img.et - exposure time
img.expbias - exposure bias
img.ext - file extension name
img.fl - focal length
img.fl35 - focal length (35 mm equivalent)
img.flash - flash information
img.fn - F/Stop (F Number, aperture)
img.fovc - field of view crop
img.h - image height
img.iso - sensitivity
img.lightsrc - light source
img.make - camera make
img.metmode - metering mode
img.model - camera model
img.name - file name
img.path - complete path to the image
img.portrait - true if image is in portrait orientation, false if it's in landscape
img.rating - number of stars
img.size - file size in bytes
img.srgb - true if sRGB color space, false otherwise
img.subdist - subject distance
img.tags - dictionary of image tags
img.time - creation time stamp (number)
img.w - image width
String functions: string.lower, string.upper, string.len, string.sub(str, from, to), string.find(str, what)
Mathematical functions: math.abs math.acos math.asin math.atan math.atan2 math.ceil math.cos math.cosh math.deg math.exp math.floor math.fmod math.frexp math.huge math.ldexp math.log math.log10 math.max math.min math.modf math.pi math.pow math.rad math.random math.randomseed math.sin math.sinh math.sqrt math.tan math.tanh math.mod
For a complete list of functions and documentation check
www.lua.org
