- ret, dst = cv2.threshold(src, thresh, maxval, type)
目录
导入图像
Original Image图像分析
BINARY图像分析
BINARY_INV图像分析
TRUNC图像分析
TOZERO图像分析
TOZERO_INV图像分析
src: 输入图,只能输入单通道图像,通常来说为灰度图
dst: 输出图
thresh: 阈值(0~255)
maxval: 当像素值超过了阈值(或者小于阈值,根据type来决定),所赋予的值
type:二值化操作的类型,包含以下5种类型:
cv2.THRESH_BINARY; cv2.THRESH_BINARY_INV; cv2.THRESH_TRUNC; cv2.THRESH_TOZERO;cv2.THRESH_TOZERO_INV
cv2.THRESH_BINARY 超过阈值部分取maxval(最大值),否则取0
cv2.THRESH_BINARY_INV THRESH_BINARY的反转
hsv=cv2.cvtColor(img,cv2.COLOR_BGR2HSV)
cv2.imshow("hsv", hsv)
cv2.waitKey(0)
cv2.destroyAllWindows()
ret, thresh1 = cv2.threshold(img_gray, 127, 255, cv2.THRESH_BINARY)
ret, thresh2 = cv2.threshold(img_gray, 127, 255, cv2.THRESH_BINARY_INV)
ret, thresh3 = cv2.threshold(img_gray, 127, 255, cv2.THRESH_TRUNC)
ret, thresh4 = cv2.threshold(img_gray, 127, 255, cv2.THRESH_TOZERO)
ret, thresh5 = cv2.threshold(img_gray, 127, 255, cv2.THRESH_TOZERO_INV)
titles = ['Original Image', 'BINARY', 'BINARY_INV', 'TRUNC', 'TOZERO', 'TOZERO_INV']
images = [img, thresh1, thresh2, thresh3, thresh4, thresh5]
for i in range(6):
plt.subplot(2, 3, i + 1), plt.imshow(images[i], 'gray')
plt.title(titles[i])
plt.xticks([]), plt.yticks([])
plt.show()
cv2.imshow('img', img)
cv2.waitKey(0)
cv2.destroyAllWindows()
ret, thresh1 = cv2.threshold(img_gray, 127, 255, cv2.THRESH_BINARY)
cv2.imshow('img', thresh1)
cv2.waitKey(0)
cv2.destroyAllWindows()参数1为图像来源,参数2为阀值(0~255),参数3最大的阀值,参数4类型 超过阈值部分取maxval(最大值),否则取0,显而易见超过172为白色,小于172为黑色。
ret, thresh2 = cv2.threshold(img_gray, 127, 255,cv2.THRESH_BINARY_INV)
cv2.imshow('img', thresh2)
cv2.waitKey(0)
cv2.destroyAllWindows()参数1为图像来源,参数2为阀值(0~255),参数3最大的阀值,参数4型 THRESH_BINARY_INV THRESH_BINARY的反转,显而易见超过172为黑色,小于172为白色。
ret, thresh3 = cv2.threshold(img_gray, 127, 255, cv2.THRESH_TRUNC)
cv2.imshow('img', thresh3)
cv2.waitKey(0)
cv2.destroyAllWindows()参数1为图像来源,参数2为阀值(0~255),参数3最大的阀值,参数4大于阈值部分设为阈值,否则不变,显而易见超过172为172,小于172为原来颜色。
ret, thresh4 = cv2.threshold(img_gray, 127, 255, cv2.THRESH_TOZERO)
cv2.imshow('img', thresh4)
cv2.waitKey(0)
cv2.destroyAllWindows()参数1为图像来源,参数2为阀值(0~255),参数3最大的阀值,参数4型大于阈值部分不改变,否则设为0,显而易见超过172为原来颜色,小于172为黑色。
ret, thresh5 = cv2.threshold(img_gray, 127, 255, cv2.THRESH_TOZERO_INV)
cv2.imshow('img', thresh5)
cv2.waitKey(0)
cv2.destroyAllWindows()参数1为图像来源,参数2为阀值(0~255),参数3最大的阀值,参数4型THRESH_TOZERO的反转,显而易见超过172为黑色,小于172为白色。
好了,第一节课到此为止,觉得有帮助,点赞三连,谢谢。持续更新,