如何更改存储为像素值的图像的对比度和亮度 [英] How to change the contrast and brightness of an image stored as pixel values

问题描述

我有一个存储为像素值数组的图像。我希望能够对此图像应用亮度或对比度滤镜。是否有任何简单的方法或算法可用于实现此目的。

I have an image that is stored as an array of pixel values. I want to be able to apply a brightness or contrast filter to this image. Is there any simple way, or algorithm, that I can use to achieve this.

这是我的代码......

Here is my code...

   PlanarImage img=JAI.create("fileload","C:\\aimages\\blue_water.jpg");
   BufferedImage image = img.getAsBufferedImage();

   int w = image.getWidth();
   int h = image.getHeight();
   int k = 0;

   int[] sbins = new int[256];
   int[] pixel = new int[3];

   Double d = 0.0;
   Double d1;
   for (int x = 0; x < bi.getWidth(); x++) {
       for (int y = 0; y < bi.getHeight(); y++) {
           pixel = bi.getRaster().getPixel(x, y, new int[3]);
           k = (int) ((0.2125 * pixel[0]) + (0.7154 * pixel[1]) + (0.072 * pixel[2]));
           sbins[k]++;
       }
   }

推荐答案

我的建议使用Java的内置方法来调整亮度和对比度，而不是尝试自己调整像素值。做这样的事情似乎很容易......

My suggestion would be to use the built-in methods of Java to adjust the brightness and contrast, rather than trying to adjust the pixel values yourself. It seems pretty easy by doing something like this...

float brightenFactor = 1.2f

PlanarImage img=JAI.create("fileload","C:\\aimages\\blue_water.jpg");
BufferedImage image = img.getAsBufferedImage();

RescaleOp op = new RescaleOp(brightenFactor, 0, null);
image = op.filter(image, image);

浮点数是亮度的百分比。在我的例子中，它会将亮度增加到现有值的120％（即比原始图像亮20％）

The float number is a percentage of the brightness. In my example it would increase the brightness to 120% of the existing value (ie. 20% brighter than the original image)

有关类似问题，请参阅此链接。 。
用Java调整BufferedImage的亮度和对比度

See this link for a similar question... Adjust brightness and contrast of BufferedImage in Java

请参阅此链接以获取示例应用程序...
http://www.java2s.com/Code/Java/Advanced-Graphics/BrightnessIncreaseDemo.htm

See this link for an example application... http://www.java2s.com/Code/Java/Advanced-Graphics/BrightnessIncreaseDemo.htm

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