Read and display an image with a strong yellow color cast.

A = imread('hallway.jpg'）；imshow（a）标题（'Original Image')

Pick a pixel in the image that should look white or gray, such as a point on a pillar. Do not pick a saturated pixel, such as a point on the ceiling light. Display the selected point in green.

x = 2800;y = 1000;gray_val = impixel（a，x，y）;drawpoint（'位置',[x y],'颜色','g'）；

Use the selected color as reference for the scene illumination, and correct the white balance of the image.

b = chromadapt（a，gray_val）;

Display the corrected image. The pillars now appear white as expected, and the rest of the image has no yellow tint.

imshow(B) title(“白色平衡图像”)

Open an image file containing minimally processed linear RGB intensities.

A = imread(“ foosballraw.tiff”）；

The image data is the raw sensor data after correcting the black level and scaling to 16 bits per pixel. Interpolate the intensities to reconstruct color. The color filter array pattern is RGGB.

a = demosaic（a，"rggb"）；

显示图像。由于图像是在线性RGB颜色空间中的，因此请应用伽马校正，以便在屏幕上正确显示图像。

a_srgb = lin2rgb（a）;imshow（a_srgb）标题（"Original Image")

该图像在场景中具有ColorChecker®图表。要获取环境光的颜色，请在图表的中性斑块之一中显示像素的RGB值。红色通道的强度低于其他两个通道的强度，这表明光是蓝绿色。

x = 1510; y = 1250; light_color = [A(y,x,1) A(y,x,2) A(y,x,3)]

light_color =1x3 uint16 row vector7361 14968 10258

Balance the color channels of the image. Use theColorSpacename-value argument to specify that the image and the illuminant are expressed in linear RGB.

b = chromadapt（a，light_color，"ColorSpace","linear-rgb"）；

用伽玛校正显示颜色平衡的图像。

B_sRGB = lin2rgb(B); imshow(B_sRGB) title("Color-Balanced Image")

Confirm that the gray patch has been color balanced. The three color channels in the color-balanced gray patch have similar intensities, as expected.

Patch_color = [B（Y，X，1）B（Y，X，2）B（Y，X，3）]

Patch_color =1x3 uint16 row vector13010 13010 13010