opencv-python-學習筆記二（利用opencv繪圖）

常見參數：

color：顏色（255，255，0），BGR表示

thickness：線寬px，-1代表填充

linetype：圓邊界類型。cv.LINE_4，cv.LINE_8，cv.LINE_AA，AA代表抗鋸齒線

shift：圖形縮小倍數

線

常見函數：

cv.arrowedLine()  箭頭線

cv.arrowedLine(img, pt1, pt2, color[, thickness[, line_type[, shift[, tipLength]]]])

pt1:箭頭起點(x,y)

pt2:箭頭終點(x,y)

tipLength:

import numpy as np
import cv2 as cv
# Create a black image
img = np.zeros((512, 512, 3), np.uint8)
cv.arrowedLine(img, (0, 0), (255, 255), (255, 255, 255))
# cv.WINDOW_AUTOSIZE  cv.WINDOW_NORMAL
cv.namedWindow('circle', cv.WINDOW_NORMAL)
# 顯示圖像
cv.imshow('circle', img)
cv.waitKey(0)
cv.destroyAllWindows()

 

cv.line() 直線

cv.line(img, pt1, pt2, color[, thickness[, lineType[, shift]]])

pt1:起點(x,y)

pt2:終點(x,y)

import numpy as np
import cv2 as cv
# Create a black image
img = np.zeros((512, 512, 3), np.uint8)


cv.line(img, (255, 255), (274, 274), (240, 240, 240), 10)

# cv.WINDOW_AUTOSIZE  cv.WINDOW_NORMAL
cv.namedWindow('circle', cv.WINDOW_NORMAL)
# 顯示圖像
cv.imshow('circle', img)
cv.waitKey(0)
cv.destroyAllWindows()

 

圓

常見函數：

cv.circle()  圓

cv.circle(img, center, radius, color[, thickness[, lineType[, shift]]])

img：

center：圓心（x,y）

radius：半徑 int

import numpy as np
import cv2 as cv
# Create a black image
img = np.zeros((512, 512, 3), np.uint8)
cv.circle(img, (447, 63), 63, (255, 255, 255), -1)
# cv.WINDOW_AUTOSIZE  cv.WINDOW_NORMAL
cv.namedWindow('circle', cv.WINDOW_NORMAL)
# 顯示圖像
cv.imshow('circle', img)
cv.waitKey(0)
cv.destroyAllWindows()

 

矩形

常見函數

cv.rectangle

cv.rectangle(img, pt1, pt2, color[, thickness[, lineType[, shift]]])

pt1：對角，左上點

pt2：對角，右下點

import numpy as np
import cv2 as cv
# Create a black image
img = np.zeros((512, 512, 3), np.uint8)
cv.rectangle(img, ((10, 10), (40, 40)), (255, 255, 255))
# cv.WINDOW_AUTOSIZE  cv.WINDOW_NORMAL
cv.namedWindow('circle')
# 顯示圖像
cv.imshow('circle', img)
cv.waitKey(0)
cv.destroyAllWindows()

 

其它

常見函數

cv.drawMarker() 在指定點出標記

cv.drawMarker(img, position, color[, markerType[, markerSize[, thickness[, line_type]]]])

position:點位置 (x,y)

markerType:標記類型

import numpy as np
import cv2 as cv
# Create a black image
img = np.zeros((512, 512, 3), np.uint8)
cv.drawMarker(img, (260, 260), (255, 255, 255)
# cv.WINDOW_AUTOSIZE cv.WINDOW_NORMAL
cv.namedWindow('circle')
# 顯示圖像
cv.imshow('circle', img)
cv.waitKey(0)
cv.destroyAllWindows()

 

 

cv.putText() 繪制文本字符串

cv.putText(img, text, org, fontFace, fontScale, color[, thickness[, lineType[, bottomLeftOrigin]]])

org:位置

text:字符串內容

fontFace:

　　

cv.FONT_HERSHEY_SIMPLEX	normal size sans-serif font
cv.FONT_HERSHEY_PLAIN	small size sans-serif font
cv.FONT_HERSHEY_DUPLEX	normal size sans-serif font (more complex than FONT_HERSHEY_SIMPLEX)
cv.FONT_HERSHEY_COMPLEX	normal size serif font
cv.FONT_HERSHEY_TRIPLEX	normal size serif font (more complex than FONT_HERSHEY_COMPLEX)
cv.FONT_HERSHEY_COMPLEX_SMALL	smaller version of FONT_HERSHEY_COMPLEX
cv.FONT_HERSHEY_SCRIPT_SIMPLEX	hand-writing style font
cv.FONT_HERSHEY_SCRIPT_COMPLEX	more complex variant of FONT_HERSHEY_SCRIPT_SIMPLEX
cv.FONT_ITALIC	flag for italic font

fontScale：字體縮放倍數

bottomLeftOrigin：true:。false:反轉。

import numpy as np
import cv2 as cv
# Create a black image
img = np.zeros((512, 512, 3), np.uint8)
# cv.circle(img, (447, 63), 63, (255, 255, 255), -1)
# cv.arrowedLine(img, (0, 0), (255, 255), (255, 255, 255))
# cv.drawMarker(img, (260, 260), (255, 255, 255)    )
# cv.line(img, (255, 255), (274, 274), (240, 240, 240), 10)
cv.putText(    img, "opencv", (200, 200), cv.FONT_HERSHEY_PLAIN, 1, (255, 255, 255))

# cv.WINDOW_AUTOSIZE  cv.WINDOW_NORMAL
cv.namedWindow('circle')
# 顯示圖像
cv.imshow('circle', img)
cv.waitKey(0)
cv.destroyAllWindows()