无法使我的多色检测阵列正常工作（Python和OpenCV）

Question

I'm trying to use a numpty array to store certain colors (HSV values) in order to be able to detect them later on by using tests. However, when I run my test it doesn't succeed. Here's the code:

#!/usr/bin/env python
import cv2
import numpy as np

class DetectAColor(object):

    @staticmethod
    def detect_a_color(image):
        img_hsv = cv2.cvtColor(image, cv2.COLOR_BGR2HSV)

        boundaries = {
            'red': ([0, 100, 100],[10, 255, 255]),
            'brown': ([14, 100, 100],[15, 255, 255]),
            'orange': ([16, 100, 100],[17, 255, 255]),
            'yellow': ([29, 100, 100],[31, 255, 255]),
            'green': ([50, 100, 100],[60, 255, 255]),
            'lightblue': ([50, 100, 100],[60, 255, 255]),
            'darkblue': ([115, 100, 100],[125, 255, 255]),
            'purple': ([149, 150, 100],[150, 255, 255]),
            'pink': ([149, 100, 150],[149, 100, 150])
            }

        for k,v in boundaries.iteritems():
            lower_color = np.array(v[0])
            upper_color = np.array(v[1])

            mask = cv2.inRange(img_hsv, lower_color, upper_color)
            amount_not_zero = cv2.countNonZero(mask)
            if amount_not_zero > 9000:
                return k
            else:
                return "Not found"

I'm testing this code with this simple test (and display the image to be 100% sure):

def test_detect_red(self):
    image = np.zeros((512, 512, 3), np.uint8)
    image[:,0:512] = (0, 0, 255) # B G R values
    color = DetectAColor.detect_a_color(image)
    cv2.imshow('image',image)
    cv2.waitKey(0)
    cv2.destroyAllWindows()

    # Controle dat de kleur gevonden wordt
    self.assertEqual("red", color)

I find it quite odd that this code isn't working, since at first it was working using the code to just detect 1 color:

#!/usr/bin/env python
import cv2
import numpy as np

class DetectAColor(object):

    @staticmethod
    def detect_a_color(image):
        img_hsv = cv2.cvtColor(image, cv2.COLOR_BGR2HSV)
        TRACK_COLOR_MIN = np.array([0, 100, 100], np.uint8)
        TRACK_COLOR_MAX = np.array([15, 255, 255], np.uint8)

        mask = cv2.inRange(img_hsv, TRACK_COLOR_MIN, TRACK_COLOR_MAX)

        cv2.imshow('mask',mask)
        cv2.waitKey(0)
        cv2.destroyAllWindows()

        amount_not_zero =  cv2.countNonZero(mask)
        if amount_not_zero > 9000:
            return "Found"
        else:
            return "Not found"

I understand the the value for H is a bit different, but I tried it with the same value as in the 1 color code and it failed as well. We've already calculated the values we needed and tested them with the 1 color method and it worked. So I need to know why I can't get it to work using the array and for loop.

Answer 1

The problem is solved by getting rid of the else statement within the for loop. Put the return "Not found" statement outside the loop.