How to find pixel color in image?-CodePudding

I am trying to make the black and white mask. Below image has mask of yellow color of chair. I am making it to white and else everything as black. I have used this color [220, 211, 81] for a mask. If i am finding this pixel color it shows that there is nothing like this. What am i doing wrong ? Code:

import cv2

color_to_seek = [220, 211, 81]
original = cv2.imread('image.png')
original = cv2.cvtColor(original, cv2.COLOR_BGR2RGB)

amount = 0
for x in range(original.shape[0]):
    for y in range(original.shape[1]):
        r, g, b = original[x, y]
        if (r, g, b) == color_to_seek:
            amount  = 1

print(amount)`

Image:

I am expecting that yellow mask should replaced by white pixels and everything as black. Is there a difference between mask or pixel color ?. Elaborate little bit ?

CodePudding user response：

As pointed by

You may need to find thresholds that have an acceptable number of false positives/false negatives for your specific application.

Example:

import cv2
import numpy as np

image = cv2.imread('room.png')

color_to_seek_rgb = np.array([142, 140, 60])
color_to_seek_hsv = cv2.cvtColor(color_to_seek_rgb.reshape(1, 1, 3).astype(np.uint8), cv2.COLOR_BGR2HSV).flatten()

image_hsv = cv2.cvtColor(image, cv2.COLOR_BGR2HSV)
# using lower values for H channel as it encodes luminance not a color information
lower_bound = color_to_seek_hsv - [10, 20, 20]
upper_bound = color_to_seek_hsv   [10, 20, 20]
mask = cv2.inRange(image_hsv, lower_bound, upper_bound)

cv2.imwrite("mask.jpg", mask)