Java BufferedImage getRGB方法和Color类 [英] Java BufferedImage getRGB method and Color class

问题描述

getRGB（x，y）方法中的x和y参数代表什么？数值返回值代表什么？

What do the x and y parameters in the getRGB(x, y) method represent? What does the numerical return value represent?

如何识别显示在DrawingPanel上的BufferedImage中的特定像素的颜色？理想情况下，我想在图像中找到一个单词，并在该单词下划线或勾勒出一个相关的超链接。如何将这些数值转换成人类可以理解的颜色，如'red''green'或'blue'？

How do I identify the color of specific pixels within a BufferedImage that is displayed on a DrawingPanel? Ideally I'd like to 'find' a word within an image, and underline or outline this word to create a relevant hyperlink. How can I translate these numerical values into human understandable colors like 'red' 'green' or 'blue'?

是的，我知道在Color类中， 0-255代表透明到不透明。但这是什么意味着实际的颜色？我很高兴澄清，如果这没有意义。感谢您阅读。

Yes, I understand that in the Color class an alpha value of 0-255 represents transparent to opaque. But what does this imply for the actual color? I'm happy to clarify if this doesn't make sense. Thank you for reading.

推荐答案

x和y坐标代表像素位置<从左到右，y从上到下（都从0开始）。所以（0,0）是左上角的像素，（width-1，height-1）是右下角的像素。

The x and y coordinates represent the pixel location, x going from left to right and y going from top to bottom (both starting at 0). So (0, 0) is the upper left pixel, and (width-1, height-1) is the bottom right pixel.

返回的整数值有R ，G，B和（潜在）Alpha值打包成单个int。记住，一个int包含32位，所以其中8位分配给每个值。

The integer value returned has the R, G, B and (potentially) Alpha values packed into a single int. Remember that an int contains 32 bits, so 8 of those bits are allocated to each of the values.

但是，如果你不好，一个整数，最简单的做法是将整数值传递给Color 的构造函数：

But, if you're not to good with shifting bits around inside an integer, the easiest thing to do is pass the integer value to the constructor of Color:

int rgba = image.getRGB(coordinates);
Color col = new Color(rgba, true);
int r = col.getRed();
int g = col.getGreen();
...

显然，识别单词来自原始像素值的位置是一个整体注意，相当复杂，问题。

Obviously, recognising where a word is from raw pixel values is a whole nother, quite complex, problem.

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