在图像上绘制网格线uisng openccv python

Question

使用opencv python，我想在打开相机时制作网格。你们能用逻辑或代码帮助我吗？ 请查看下面的图片链接以便更好地理解。

Camera switched on and pointed to a floor

Grid Lines are splitted across the whole image

Answer 1

以下是我的问题解答。利用它。

import matplotlib.pyplot as plt
import matplotlib.ticker as plticker
try:
    from PIL import Image
except ImportError:
    import Image

# Open image file
image = Image.open('bird.jpg')
my_dpi=200.

# Set up figure
fig=plt.figure(figsize=(float(image.size[0])/my_dpi,float(image.size[1])/my_dpi),dpi=my_dpi)
ax=fig.add_subplot(111)

# Remove whitespace from around the image
fig.subplots_adjust(left=0,right=1,bottom=0,top=1)

# Set the gridding interval: here we use the major tick interval
myInterval=300.
loc = plticker.MultipleLocator(base=myInterval)
ax.xaxis.set_major_locator(loc)
ax.yaxis.set_major_locator(loc)

# Add the grid
ax.grid(which='major', axis='both', linestyle='-', color='g')

# Add the image
ax.imshow(image)

# Find number of gridsquares in x and y direction
nx=abs(int(float(ax.get_xlim()[1]-ax.get_xlim()[0])/float(myInterval)))
ny=abs(int(float(ax.get_ylim()[1]-ax.get_ylim()[0])/float(myInterval)))




# Save the figure
fig.savefig('birdgrid_without_Label.jpg')

Answer 2

您可以使用cv2.line()功能在输入图像上绘制线条。因此，根据您想要绘制线条的位置，您的基本代码将如下所示：

img = cv2.imread(r"path\to\img")
cv2.line(img, (start_x, start_y), (end_x, end_y), (255, 0, 0), 1, 1)

要获取图片的尺寸，您可以使用img.shape，它将返回(height, width)。

例如，要在中心绘制一条垂直线，您的代码将如下所示：

cv2.line(img, (img.shape[1]/2, 0), (img.shape[1]/2, img.shape[0]), (255, 0, 0), 1, 1)

Answer 3

def draw_grid(img, line_color=(0, 255, 0), thickness=1, type_=_cv2.LINE_AA, pxstep=50):
    '''(ndarray, 3-tuple, int, int) -> void
    draw gridlines on img
    line_color:
        BGR representation of colour
    thickness:
        line thickness
    type:
        8, 4 or cv2.LINE_AA
    pxstep:
        grid line frequency in pixels
    '''
    x = pxstep
    y = pxstep
    while x < img.shape[1]:
        _cv2.line(img, (x, 0), (x, img.shape[0]), color=line_color, lineType=type_, thickness=thickness)
        x += pxstep

    while y < img.shape[0]:
        _cv2.line(img, (0, y), (img.shape[1], y), color=line_color, lineType=type_, thickness=thickness)
        y += pxstep