如何使用 fillConvexPoly 从所有轮廓制作蒙版

Question

我正在尝试根据轮廓制作面具。 Here's my full df

前 7 行一览

>>> df
      contour.ID        xrT        yrT        xlT        ylT
1057          20  6259.2300  4620.7845  5670.1260  4651.4670
1058          20  6253.0935  4620.7845  5682.3990  4651.4670
1059          20  6253.0935  4633.0575  5694.6720  4657.6035
1060          20  6240.8205  4633.0575  5694.6720  4657.6035
1061          20  6228.5475  4645.3305  5700.8085  4669.8765
1062          20  6228.5475  4645.3305  5700.8085  4669.8765
1063          20  6216.2745  4645.3305  5713.0815  4669.8765

我可以使用函数绘制所有我关心的轮廓。

def display_all_contours(img, df, grouping_var):
    # display with matplotlib

    # Create figure and axes
    fig, ax = plt.subplots(1)

    # Display the image
    ax.imshow(img)

    # split by contour
    grouped_frame = df.groupby(grouping_var)
    li = [grouped_frame.get_group(x) for x in grouped_frame.groups]

    # for every contour
    for i in range(len(li)):
        poly = patches.Polygon(np.array([li[i].xrT, li[i].yrT]).T,
                               fill=False)
        ax.add_patch(poly)

    for i in range(len(li)):
        poly = patches.Polygon(np.array([li[i].xlT, li[i].ylT]).T,
                               fill=False, color="white")
        ax.add_patch(poly)

    return("Displaying " + str(len(np.unique(df[grouping_var]))) + " contours.")

这是在具有我图像形状的物体上绘制圆锥体的结果。

mask = np.zeros((9373, 12273), dtype=np.uint8)

display_all_contours(mask, df, "contour.ID")

问题

现在，我想创建一个包含所有多边形的蒙版（在本例中为左侧）。所以我创建了一个遮罩并使用 cv2.fillConvexPoly

将每个多边形刻录到其中

mask = np.zeros((9373, 12273), dtype=np.uint8)

display_all_contours(mask, df, "contour.ID")

for poly in np.unique(df["contour.ID"]):
    # subset
    sub_df = df[df["contour.ID"] == poly]
    # burn into the mask
    # explicitly burn into the mask
    mask = cv2.fillConvexPoly(mask, np.array(sub_df[["xlT", "ylT"]], 'int32'), 1)

由于某些我不明白的原因，这并没有产生我想要的结果。

plt.imshow(mask)

Answer 1

解决了，其实我要找的功能是fillPoly

替换这条线解决问题

# mind the np.array(..., "int32") is wrapped in [] because that's how fillPoly likes it
mask = cv2.fillPoly(mask, [np.array(sub_df[["xlT", "ylT"]], 'int32')], 1)

如何使用 fillConvexPoly 从所有轮廓制作蒙版

How to make mask from all contours with fillConvexPoly

python

opencv

mask

image-processing

问题