Used in cvd_emulator. Takes an image object and converts the colors using deutan, protan, tritan, desaturate functions. The image will be written to disc as a PNG file.

cvd_image(img, type, file, severity = 1, linear = TRUE)



character or array as returned by readPNG and readJPEG of size height x width x depth. The depth coordinate contains R/G/B and alpha if given (png). In case of a single character string img has to be the full path to an image of type png or jpg/jpeg.


string name of the function which will be used to convert the colors (deutan, protan, tritan, desaturate). If set to original the image will be written as is.


string with (full) path to resulting image. Has to be a png image name.


numeric. Severity of the color vision defect, a number between 0 and 1.


logical. Should the color vision deficiency transformation be applied to the linearized RGB coordinates (default)? If FALSE, the transformation is applied to the gamma-corrected sRGB coordinates (which was the default up to version 2.0-3 of the package).