section of routines in dichromat.i

functions in dichromat.i -

 
 
 
dichromap


             dichromap, type  
         or dichromap  
 
    Modify the current colormap to see how the plot (pli, plf, or  
    plfc) would appear to a dichromat of the given TYPE, which is 1,  
    2, 3 (or "p", "d", "t") to simulate protan, deuteran, or tritan  
    vision.  See help, dichromat for more.  Omitting TYPE toggles the  
    original color map with the modified one provided the current  
    colormap is still the one installed by dichromap.  
SEE ALSO: dichromat,   cmap  
 
 
 
dichromat


             drgb = dichromat(type, rgb)  
         or drgb = dichromat(type, r, g, b)  
 
    
    Return colors DRGB perceived by a dichromat of TYPE corresponding  
    to screen colors RGB = [r,g,b], or R, G, B.  The return value has  
    the same dimensions as RGB or [R,G,B].  There are three classes  
    of dichromats (colorblind people): Protrans, Deuterans, and  
    Tritans, according to whether they lack long, medium, or short  
    wavelength cone cells (or which type of cell is damaged).  For  
    good background material, see  
    http://en.wikipedia.org/wiki/Color_blindness or  
    http://cvrl.ioo.ucl.ac.uk/ and for details of the algorithm  
    implemented here see Brettel et al., JOSA 14, 2647 (1997),  
    http://perso.telecom-paristech.fr/~brettel.  By default, DRGB is  
    a char array, but with cmax=1, you can get a double array.  The  
    input RGB can be a char array, or any integer datatype with a  
    maximum of 255, or a floating point array with maximum 1.0.  Both  
    input and output are sRGB values, that is, the RGB of your  
    monitor; see the rgb_s2l and rgb_l2s functions for conversions to  
    physically linear ("gamma corrected") RGB values.  
    
    TYPE is 1 for protran, 2 for deuteran, or 3 for tritan dichromatism.  
    You may also pass any string beginning with "p", "d", or "t",  
    respectively.  The dichromat function projects the three dimensional  
    RGB onto a two dimensional subspace, so that there are only two primary  
    colors instead of three.  Note that tritan dichromatism is quite rare,  
    while some male in a room of 20 probably suffers from either  
    deuteran or (less likely) protan dichromacy.  
    
    Use the dichromap function to quickly check a pseudocolor picture  
    made with pli, plf, or plfc to see how it appears to a dichromat.  
    
SEE ALSO: dichromap,   dichromat_setup,   rgb_s2l,   rgb_l2s  
 
 
 
dichromat_setup


             dichromat_setup, xylms, xypri  
 
    Set up the dichromatic projection matrices and selection tests for  
    the dichromat function.  XYLMS is either a 2x3 or 3x3 array of the  
    CIE xy or XYZ color coordinates of the L, M, and S spectral responses  
    of the three retinal cone cells responsible for color vision.  There  
    is some dispute about exactly what colors these are, since the  
    experiments to find them are difficult.  XYPRI is either a 2x2x3 or  
    3x2x3 of the xy or XYZ color coordinates of the pairs of primary  
    trichromatic colors which will be used to represent what the dichromat  
    sees.  The third index is [protan,deuteran,tritan].  These should be  
    chosen so that the colors returned by the dichromat function are  
    indistinguishable from the input colors by that particular type of  
    dichromat.  
SEE ALSO: dichromat