OpenCV Android绿色检测 [英] OpenCV Android Green Color Detection

问题描述

目前我在做一个应用程序，用户将检测绿色。我使用这张照片进行测试：

我的问题是我无法检测到任何绿色像素。在我使用蓝色和一切工作正常之前。现在我不能检测到任何东西，虽然我尝试不同的组合 RGB 。我想知道它是否与绿色或我的检测范围有问题，所以我使用（0，255，0）在画油漆图像，它的工作。为什么看不到此圈子？我使用这个代码进行检测：

  Core.inRange（hsv_image，new Scalar（[I change this value]），new Scalar （60，255，255），ultimate_blue）; 
  

这可能是我设置了错误的Range，但我使用Photoshop获得绿色像素并将 RGB 的值转换为 HSV 。但它不工作。它甚至不检测我已经采样的像素。怎么了？提前感谢。

使用Miki的回答：

解决方案

绿色是HSV空间的H = 120，范围为[0,360]。

OpenCV将H值减半以适应范围[0,255]，因此H值而不是范围[0,360]在范围[0,180]内。
S和V仍在[0,255]范围内。

因此，绿色的H值为60 = 120 / / p>

您的上限和下限应为：

  a int，通常设置为15  -  20 
 [60  -  sensitivity，100，100] 
 [60 + sensitivity，255，255] 
  

---

UPDATE

图像非常暗，您需要为V使用下限。使用这些值：

  sensitivity = 15; 
 [60  -  sensitivity，100，50] //下界
 [60 + sensitivity，255，255] //上界
  

生成的掩码将是：

有关详情，请参阅此答案。

currently I'm making an app where user will detect green colors. I use this photo for testing:

My problem is that I can not detect any green pixel. Before I worked with blue color and everything worked fine. Now I can't detect anything though I tried different combinations of RGB. I wanted to know whether it's problem with green or my detection range, so I made an image in paint using (0, 255, 0) and it worked. Why it can't see this circle then? I use this code for detection:

Core.inRange(hsv_image, new Scalar([I change this value]), new Scalar(60, 255, 255), ultimate_blue);

It could have been that I set wrong Range, but I use Photoshop to get color of one of green pixels and convert RGB value of it into HSV. Yet it doesn't work. It don't detect even pixel that I've sampled. What's wrong? Thanks in advance.

Using Miki's answer:

解决方案

Green color is HSV space has H = 120 and it's in range [0, 360].

OpenCV halves the H values to fit the range [0,255], so H value instead of being in range [0, 360], is in range [0, 180]. S and V are still in range [0, 255].

As a consequence, the value of H for green is 60 = 120 / 2.

You upper and lower bound should be:

// sensitivity is a int, typically set to 15 - 20 
[60 - sensitivity, 100, 100]
[60 + sensitivity, 255, 255]

---

UPDATE

Since your image is quite dark, you need to use a lower bound for V. With these values:

sensitivity = 15;
[60 - sensitivity, 100, 50]  // lower bound
[60 + sensitivity, 255, 255] // upper bound

the resulting mask would be like:

You can refer to this answer for the details.

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