RGB to HSV convert function

myRgb2Hsv.m

% myRgb2Hsv.m
% by Dzone 150306_14:03 
function arryHsv = myRgb2Hsv(arryRgb)

% RGB is normalized value (0.0 to 1.0)
[sx,sy,sp] = size(arryRgb);
red = reshape(arryRgb(:,:,1),sx*sy,1);
green = reshape(arryRgb(:,:,2),sx*sy,1);
blue = reshape(arryRgb(:,:,3),sx*sy,1);

[maxv,maxi] = max([red,green,blue].');
[minv,mini] = min([red,green,blue].');
maxv=maxv.';
maxi=maxi.';
minv=minv.';
mini=mini.';

divv = maxv - minv;

isGray= (red==green)&&(blue==green);
hue = (1-isGray).*(...
	(mini==1).*((blue - green)*60./divv + 180)...
	+ (mini==2).*((red - blue)*60./divv + 300)...
	+ (mini==3).*((green - red)*60./divv + 60) ); % isGray==1 then 0

%--- hue must be 0 to 360
hue = (hue > 360).*(hue - 360*floor(hue/360)) ...
	+ (hue < 0).*(hue - 360*floor(hue/360)) ...
	+ (hue <= 360).*(hue >= 0).*hue;

%--- normalized by 360 deg
hue = hue / 360;

sat = divv./maxv;
bri = maxv;

hue = reshape(hue , sx,sy);
sat = reshape(sat , sx,sy);
bri = reshape(bri , sx,sy);

arryHsv  = cat(3, hue, sat, bri);

endfunction