Question

我有一个numpy数组，我在数组中减去一个常量值。我希望这些值在必要时变为负值（而不是环绕或降低为零）。然后，我需要提取所有零附近的数组值，并生成一个新的二进制数组/图像。因此，生成的图像在接近零的区域中将显示为白色。

我已经尝试实现此功能，但是它很笨拙，我不确定它是否正确。您能协助我在上面做些什么吗？

# roi is a numpy array/image in Cielab colour space
swatch_colour = (255, 10, 30) # Cielab colour space
swatch_roi = np.full((roi.shape[0], roi.shape[1], 3), swatch_colour, dtype='int8')
int_roi = roi.astype('int8')
diff = np.subtract(int_roi, swatch_roi)

thresh = diff.copy()
# Get all pixels whose Cielab colour is close to zero
thresh[np.abs(thresh) < (12,6,12)] = 0
# the remaining pixels are greater than/less than the above threshold
thresh[np.abs(thresh) > (0,0,0)] = 255

thresh = thresh.astype('uint8')
# convert from 3 channels to 1 channel
thresh = cv2.cvtColor(thresh, cv2.COLOR_BGR2GRAY)
# Invert the image so that the pixels that were close to zero are white
thresh = cv2.bitwise_not(thresh)

Answer 1

Numpy可以索引切片逻辑运算符

你为什么可以做类似的事情？

image[image.logical_and( image > -05 , image < 05 )]

https://docs.scipy.org/doc/numpy/reference/generated/numpy.logical_and.html

识别所有接近零的值

1 个答案: