if hue > 360 then if hue <0 then hue =hue+360 if hue>=240 then result =nl if hue<240 then result: =n1+(n2-n1)*(240-hue )60 if hue< 180 then resu ult: =n1+(n2-n1)*hue/60 end procedure rgb2hsl(r,g, b: integer; var h, S, I real); cl c2 c3, delta, kmin, kmax: real minmax: array[1.3] of double cl=r/255; c2:=g/255 2]}= minmax[3]: =c3 kmax:=maxvalue(minmax) H Evaluate luminosity j 1: =(kmaxkmin)/2 Evaluate saturation if kr kmin then 0 if1<=0.5 then S: =(kmax-kmin (kmax+kmin) else 6
6 begin if hue >= 360 then hue := hue-360 else if hue < 0 then hue := hue+360; if hue>=240 then result := n1; if hue<240 then result := n1+(n2-n1)*(240-hue)/60; if hue<180 then result := n2; if hue < 60 then result := n1+(n2-n1)*hue/60; end; ************************************* procedure rgb2hsl (r,g,b :integer ;var h, s, l :real); var c1,c2,c3,delta,kmin,kmax :real; minmax:array[1..3] of double; begin c1:=r/255; c2:=g/255; c3:=b/255; minmax[1]:=c1; minmax[2]:=c2; minmax[3]:=c3; kmin:= minvalue(minmax); kmax:=maxvalue(minmax); {Evaluate luminosity } l := (kmax+kmin)/2; {Evaluate saturation} if kmax = kmin then begin s := 0; h:= 0; end else begin if l <= 0.5 then s := (kmax-kmin)/(kmax+kmin) else
S:=(kmax-kmin )/(2-kmax-kmin) Evaluate Hue) delta kmax-kmin if kmax = cl then h: =(c2-c3)delta if kmax c2 then h: =2+(c3-cl)delta if kmax = c3 then h: =4+(cl-c2)delta h:=h*60 if h<o then h:=h+360 end end procedure hsl2rgb(h, S, I: real var r,g, b: integer ) cl c2c3. m1 m2: real if K<=0.5 then m2:=1*(1+ m2:=|+s*(1-1), ml:=2*}-m2 cl: valore(ml, m2, h+120) c2: =valore(ml, m2, h) c3: = valore(ml, m2, h-120) if(s=0)and(h=0)then c2s l; l; r:=round(cl*255) round(c2*255) b: =round(c3*255) 3.HSI和RGB (1)执行RGB→HS转换的参考程序 /*****幸本*家家*****事容***容本*家*家本********亲*本春水* Converts a rgb value to a hsi value 7
7 s := (kmax-kmin)/(2-kmax-kmin) ; {Evaluate Hue} delta := kmax-kmin ; if kmax = c1 then h := (c2-c3)/delta; if kmax = c2 then h := 2+(c3-c1)/delta; if kmax = c3 then h := 4+(c1-c2)/delta ; h := h*60; if h<0 then h := h+360; end; end; ************************************* procedure hsl2rgb (h, s, l : real ;var r,g,b : integer); var c1,c2,c3,m1,m2 : real; begin if l<=0.5 then m2 := l*(1+s) else m2 := l+s*(1-l); m1 := 2*l-m2; c1 := valore(m1,m2,h+120); c2 := valore(m1,m2,h); c3 := valore(m1,m2,h-120); if (s = 0) and (h = 0) then begin c1 := l; c2 := l; c3 := l; end; r:=round(c1*255); g:=round(c2*255); b:=round(c3*255); end; 3. HSI 和 RGB (1) 执行 RGB→HIS 转换的参考程序 /**************************************************************** * Converts a RGB value to a HSI value