python中的opencv

cv2.rectangle(img, pt1, pt2, color[, thickness[, lineType[, shift]]]) → None

img – Image.
pt1 – Vertex of the rectangle.
pt2 – Vertex of the rectangle opposite to pt1 .
color – Rectangle color or brightness (grayscale image).
thickness – Thickness of lines that make up the rectangle. Negative values, like CV_FILLED , mean that the function has to draw a filled rectangle.
lineType – Type of the line. See the line() description.
8 (or omitted) - 8-connected line.
4 - 4-connected line.
CV_AA - antialiased line.
shift – Number of fractional bits in the point coordinates.

pt1:(x1,y1)

pt2:(x2,y2)

 

 

Python-OpenCV 图像叠加or图像混合加权实现
函数说明
cv2.addWeighted(src1, alpha, src2, beta, gamma[, dst[, dtype]]) → dst
1
参数说明
src1 – first input array.
alpha – weight of the first array elements.
src2 – second input array of the same size and channel number as src1.
beta – weight of the second array elements.
dst – output array that has the same size and number of channels as the input arrays.
gamma – scalar added to each sum.
dtype – optional depth of the output array; when both input arrays have the same depth, dtype can be set to -1, which will be equivalent to src1.depth().
此函数可以用一下矩阵表达式来代替：

dst = src1 * alpha + src2 * beta + gamma;