Version 3.1.0
New properties
The image width/height can be specified in pixels.
See https://jspsychophysics.hes.kyushu-u.ac.jp/objectProperties/#obj_type-image
The contrastPreMultiplicator property is added.
See https://jspsychophysics.hes.kyushu-u.ac.jp/objectProperties/#obj_type-gabor and CreateProceduralGabor.