《ie工业工程_色度学原理与cie标准色度学系统》由会员分享，可在线阅读，更多相关《ie工业工程_色度学原理与cie标准色度学系统（113页珍藏版）》请在金锄头文库上搜索。
1、第2章 色度学原理与 CIE 标准色度学系统,Prologue This is the story of Mister Chrome who started out to paint his home. The paint ran out when half away through so to the store he quickly flew to buy some more of matching hue, a delicate shade of egg-shell blue. But when he tried this latest batch, he found it simply
2、 didnt match. No wonder he was in a fix, for of the colors we can mix, the major shades and those between, ten million different can be seen.,You foolish man, said Missis Chrome, you should have taken from the home a simple of the color done; you cant remember every one. Taking care that she had got
3、 a sample from the early pot, she went and bought her husband more of better color from the store. Before she paid, she checked the shade, and found a perfect match it made. In triumph now she took it home, and gave it straight to Mister Chrome. He put it on without delay, and found the color now ok
4、ey.,But, after dark, in tungsten light, they found the color still not right. So to the store they both went now, with samples clear, and asked them how a paint that matched in daylight bright could fail to match in tungsten light. The mans reply to their complaint was that the pigments in the paint
5、 had been exchanged, since they had bought, for others of a different sort. To solve the problem on their wall, he gave them paint to do it all from just one batch of constant shade, and then at last success was made.,To compensate them for their trouble, the store sent to them curtains double. They
6、 hung them up with great delight; they matched in tungsten and daylight. A neighbor then did make a call and fixed his eye upon the wall; the paint, he said was all one color, but clearly saw the curtains duller! Though colors strange at times appear, the moral of this tale is clear: to understand j
7、ust what we see, object, light, and eye, all three, must color all our thinking through of chromic problems, old or new!,2.1 色度学实验依据,2.1.1 颜色匹配实验,颜 色 转 盘,颜色光的匹配实验,2.1.2 同颜色光亮度的相加,设有三个不同颜色的色光 ：P*、Q*、R* 相应色的单位量值：P、Q、R p、q、r 分别为颜色P*、Q*、R*的强度。 调出P/ Lp、Q / Lq、R / Lr，使这些光亮度相等。Lp、Lq、Lr即为单位颜色P、Q、R的光亮度比值。 选择
8、光亮度单位，则Lp、Lq、Lr为P、Q、R各单位颜色的光亮度值。 因此，Lp、Lq、Lr是单位颜色P、Q、R 的光亮度系数。,2.1.2 同颜色光亮度的相加,p P、q Q两色混合，与 r R光亮度比较 实验证明： 当 p、q、r 满足下列数值关系时，被比较的两光亮度相等。 p Lp + q Lq = r Lr （2-1） 物理意义： 不论颜色的成分如何，各种颜色重叠的光亮度是可以相加的。,2.2 颜色的数学表示,2.2.1 色三角形 色度匹配：色光相同的颜色和亮度 色度：色光的颜色和亮度的统称,色坐标 ： （r，g。b）,2.2.2 颜色方程,三原色R*、G*、B* 、任意色C*看成是色向量
9、， 相应的单位向量R、G、B以及C。 R*= RR、 G*= GG、 B*= BB、C* =CC 当颜色C* 与RR、 GG、 BB 混合视觉上匹配时，则可写出颜色方程： CC= RR + GG + BB (2-2) 此时称 R、G、B 为颜色C*的三刺激值。,色光匹配： Red Green Blue nm 700 546.1 435.8,2.2.2 颜色方程,在颜色转盘实验中，如果被匹配的颜色(转盘中心)很饱和，那么用红、绿、蓝三原色可能实现不了匹配。在这种情况下，如图2-1 (b)所示匹配。 颜色匹配方程：CC + BB= RR + GG 可写成：CC = RR + GG - BB (2-
10、3),颜色转盘,the sensitivity curves of the three types of cone,等能白：SE Red Green Blue Mixture cd/m2 1.0000 4.5907 0.0691 5.6508 1 Red unit = R = 1.0000 cd/m2 ; 1 Green unit = G = 4.5907 cd/m2 ; 1 Blue unit = B = 0.0691 cd/m2 . 100 B produce : 100 5 4 100 G produce : 0 100 75 100 R produce : 0 0 100,To mat
11、ch 1 power unit of 500 nm 1 unit of 500 nm produces 20 40 20 20 B 20 1 0.8 39 G 0 39 29.2 20 B + 39 G = 20 40 30 1 unit of 500 nm produces 20 40 20 10 of R produces 0 0 10 1 500 nm +10 R = 20 40 30 1 500 nm +10 R is matched by 39 G + 20 B 1 500 nm = -10 R + 39 G + 20 B 1 600 nm = 95 R + 30 G + 0 B 1
12、 500 nm + 1 600 nm = 85 R + 69 G + 20 B,2.2.2 颜色方程,在颜色科学中，我们不直接用三刺激值R、G、B来表示颜色，而用三原色各自占R+G+B总量的相对比值表示颜色。 色度坐标：三原色各自占R+G+B总量的相对比值。 对颜色C*而言，其色度坐标为： r = R / (R+G+B) g = G / (R+G+B) b = B / (R+G+B) 颜色C*的单位值：C = r R + g G + b B 则颜色C*的色量C： C = R + G + B。,白色的单位向量 W,令 W = (1/3)R + (1/3)G + (1/3)B W色度坐标：r =
13、1/3、g = 1/3、b = 1/3 相应 R、G、B 的相对光亮度值： LR= 1.0000 、LG = 4.5907 、LB = 0.0691 ， 从而颜色C*的单位光亮度为 LC = r LR + g LG + b LB 若已知颜色C*的光亮度为L，并且测量得颜色C*的r、g、b值，则颜色C*的色量为 C = L / LC = L / ( r LR + g LG + b LB ),2.3 色度相加原理,根据格拉斯曼配色混合的代替律， 如果色光A* =色光B*，色光C* = 色光D*， 则 A* + C* = B* + D*。 此式说明色光相加符合数学上的向量加法法则。,2.3 色度相加
14、原理,2 色光混合： 设色光 C1C1 C2C2 三刺激值： R1、G1、B1 R2、G2、B2 色度坐标： r1、g1、b1 r2、g2、b2 经过色光混合后色光为C12C12，则颜色C12C12为 C12C12 = C1C1 + C2C2 = R1R + G1G + B1B+ R2R + G2G + B2B = (R1 + R2)R + (G1 + G2 )G + (B1 + B2 )B =(C1r1+C2r2)R+(C1g1+C2g2)G+(C1b1+C2b2)B,所以 C12 = C1(r1 + g1 + b1) + C2(r2 + g2 + b2) = C1 + C2,这就是说，在色三角形坐标中两色混合的色度，相当于C1*、C2*两色依其色量C1 、C2而形成的重心点。,n 个不同色颜色相混合,则其色度坐标应为：,2.4 色谱图,实验中采用：光谱色+ 适当的白光 例： C500*= C1C1 = W1W + Co* ， Co* = G1G + B1B ， 因而有：C1C + W1W = G1G + B1B,确定 R*、G*、B*，与各种不同波长的单色光的颜色相匹配，从而得出各光谱单色光相对于选定三原色的色度值。光谱色是最纯的，想
