Matlab基本函数-contrast函数

1、contrast函数：调整灰色对比度

2、用法说明：

（1）cmap = contrast(x) 函数返回一灰度色图cmap，该色图与当前色图x有相同的维数

（2）cmap = contrast(x,m) 函数返回维数为m×3的当前色图x的灰度色图cmap

3、实例

（1）显示框图

>> load clown>> cmap1 = contrast(X)cmap1 =    0.1249    0.1249    0.1249    0.2387    0.2387    0.2387    0.2636    0.2636    0.2636    0.2650    0.2650    0.2650    0.3009    0.3009    0.3009    0.3093    0.3093    0.3093    0.3700    0.3700    0.3700    0.3770    0.3770    0.3770    0.4078    0.4078    0.4078    0.4426    0.4426    0.4426    0.4633    0.4633    0.4633    0.4711    0.4711    0.4711    0.4794    0.4794    0.4794    0.4907    0.4907    0.4907    0.4918    0.4918    0.4918    0.5005    0.5005    0.5005    0.5081    0.5081    0.5081    0.5586    0.5586    0.5586    0.5600    0.5600    0.5600    0.5603    0.5603    0.5603    0.6005    0.6005    0.6005    0.6216    0.6216    0.6216    0.6223    0.6223    0.6223    0.6399    0.6399    0.6399    0.6539    0.6539    0.6539    0.6547    0.6547    0.6547    0.6554    0.6554    0.6554    0.6626    0.6626    0.6626    0.6856    0.6856    0.6856    0.7062    0.7062    0.7062    0.7072    0.7072    0.7072    0.7097    0.7097    0.7097    0.7447    0.7447    0.7447    0.7638    0.7638    0.7638    0.7831    0.7831    0.7831    0.7944    0.7944    0.7944    0.7948    0.7948    0.7948    0.7953    0.7953    0.7953    0.7963    0.7963    0.7963    0.7971    0.7971    0.7971    0.7990    0.7990    0.7990    0.7991    0.7991    0.7991    0.8181    0.8181    0.8181    0.8377    0.8377    0.8377    0.8380    0.8380    0.8380    0.8481    0.8481    0.8481    0.8592    0.8592    0.8592    0.8725    0.8725    0.8725    0.8726    0.8726    0.8726    0.8762    0.8762    0.8762    0.8822    0.8822    0.8822    0.8824    0.8824    0.8824    0.8827    0.8827    0.8827    0.8862    0.8862    0.8862    0.9098    0.9098    0.9098    0.9106    0.9106    0.9106    0.9174    0.9174    0.9174    0.9309    0.9309    0.9309    0.9310    0.9310    0.9310    0.9379    0.9379    0.9379    0.9744    0.9744    0.9744    0.9794    0.9794    0.9794    0.9984    0.9984    0.9984    1.0000    1.0000    1.0000

（2）显示图像

>> image(X)

（3）调整图片的灰度

>> colormap(cmap1)

（4）cmap = contrast(x,m)

>> cmap1 = contrast(X,100)cmap1 =    0.1248    0.1248    0.1248    0.2385    0.2385    0.2385    0.2412    0.2412    0.2412    0.2412    0.2412    0.2412    0.2635    0.2635    0.2635    0.2649    0.2649    0.2649    0.3008    0.3008    0.3008    0.3092    0.3092    0.3092    0.3092    0.3092    0.3092    0.3152    0.3152    0.3152    0.3698    0.3698    0.3698    0.3768    0.3768    0.3768    0.4076    0.4076    0.4076    0.4076    0.4076    0.4076    0.4394    0.4394    0.4394    0.4424    0.4424    0.4424    0.4631    0.4631    0.4631    0.4709    0.4709    0.4709    0.4709    0.4709    0.4709    0.4793    0.4793    0.4793    0.4841    0.4841    0.4841    0.4905    0.4905    0.4905    0.4916    0.4916    0.4916    0.4917    0.4917    0.4917    0.5003    0.5003    0.5003    0.5080    0.5080    0.5080    0.5560    0.5560    0.5560    0.5584    0.5584    0.5584    0.5598    0.5598    0.5598    0.5598    0.5598    0.5598    0.5602    0.5602    0.5602    0.5968    0.5968    0.5968    0.6003    0.6003    0.6003    0.6215    0.6215    0.6215    0.6215    0.6215    0.6215    0.6221    0.6221    0.6221    0.6398    0.6398    0.6398    0.6526    0.6526    0.6526    0.6538    0.6538    0.6538    0.6538    0.6538    0.6538    0.6545    0.6545    0.6545    0.6553    0.6553    0.6553    0.6625    0.6625    0.6625    0.6638    0.6638    0.6638    0.6638    0.6638    0.6638    0.6855    0.6855    0.6855    0.7060    0.7060    0.7060    0.7071    0.7071    0.7071    0.7096    0.7096    0.7096    0.7096    0.7096    0.7096    0.7345    0.7345    0.7345    0.7446    0.7446    0.7446    0.7637    0.7637    0.7637    0.7830    0.7830    0.7830    0.7937    0.7937    0.7937    0.7937    0.7937    0.7937    0.7943    0.7943    0.7943    0.7947    0.7947    0.7947    0.7951    0.7951    0.7951    0.7962    0.7962    0.7962    0.7962    0.7962    0.7962    0.7965    0.7965    0.7965    0.7970    0.7970    0.7970    0.7989    0.7989    0.7989    0.7990    0.7990    0.7990    0.7990    0.7990    0.7990    0.8180    0.8180    0.8180    0.8234    0.8234    0.8234    0.8376    0.8376    0.8376    0.8379    0.8379    0.8379    0.8379    0.8379    0.8379    0.8480    0.8480    0.8480    0.8486    0.8486    0.8486    0.8592    0.8592    0.8592    0.8724    0.8724    0.8724    0.8725    0.8725    0.8725    0.8725    0.8725    0.8725    0.8762    0.8762    0.8762    0.8820    0.8820    0.8820    0.8822    0.8822    0.8822    0.8823    0.8823    0.8823    0.8823    0.8823    0.8823    0.8827    0.8827    0.8827    0.8861    0.8861    0.8861    0.8884    0.8884    0.8884    0.9098    0.9098    0.9098    0.9098    0.9098    0.9098    0.9106    0.9106    0.9106    0.9173    0.9173    0.9173    0.9300    0.9300    0.9300    0.9309    0.9309    0.9309    0.9309    0.9309    0.9309    0.9310    0.9310    0.9310    0.9379    0.9379    0.9379    0.9744    0.9744    0.9744    0.9761    0.9761    0.9761    0.9761    0.9761    0.9761    0.9794    0.9794    0.9794    0.9984    0.9984    0.9984    1.0000    1.0000    1.0000