CV2堆肥2张不同尺寸的图像

Question

我需要对2张不同尺寸的图像进行alpha混合。我已经设法通过调整大小到相同的大小来使它们复合，所以我有一部分逻辑：

import cv2 as cv

def combine_two_color_images_composited(foreground_image, background_image):

    foreground = cv.resize(foreground_image, (400,400), interpolation=cv.INTER_CUBIC).copy()
    background = cv.resize(background_image, (400,400), interpolation=cv.INTER_CUBIC).copy()
    alpha =0.5
    # do composite of foreground onto the background
    cv.addWeighted(foreground, alpha, background, 1 - alpha, 0, background)

    cv.imshow('composited image', background)
    cv.waitKey(10000)

我想知道是否需要制作与较大图像尺寸相同的面具，然后将其与第一张图像一起使用。如果是这样，我不知道如何在CV2中进行掩蔽....这只是我项目的一小部分，所以我不能花费大量时间研究如何掩盖工作。

我已经搜索了所有，但我找到的代码做的事情就像'添加'图像在一起（并排）。

Answer 1

要合并这两个图像，您可以使用numpy切片选择要混合前景的背景图像部分，然后再次在背景中插入新混合的部分。

def combine_two_color_images(image1, image2):

    foreground, background = img1.copy(), img2.copy()

    foreground_height = foreground.shape[0]
    foreground_width = foreground.shape[1]
    alpha =0.5

    # do composite on the upper-left corner of background image.
    blended_portion = cv.addWeighted(foreground,
                alpha,
                background[:foreground_height,:foreground_width,:],
                1 - alpha,
                0,
                background)
    background[:foreground_height,:foreground_width,:] = blended_portion
    cv.imshow('composited image', background)

    cv.waitKey(10000)

编辑：要将前景放在指定位置，您可以像以前一样使用numpy indexing。 Numpy索引非常强大，你会发现它在很多场合都很有用。我链接了上面的文档。真的值得一看。

def combine_two_color_images_with_anchor(image1, image2, anchor_y, anchor_x):
    foreground, background = img1.copy(), img2.copy()
    # Check if the foreground is inbound with the new coordinates and raise an error if out of bounds
    background_height = background.shape[1]
    background_width = background.shape[1]
    foreground_height = foreground.shape[0]
    foreground_width = foreground.shape[1]
    if foreground_height+anchor_y > background_height or foreground_width+anchor_x > background_width:
        raise ValueError("The foreground image exceeds the background boundaries at this location")

    alpha =0.5

    # do composite at specified location
    start_y = anchor_y
    start_x = anchor_x
    end_y = anchor_y+foreground_height
    end_x = anchor_x+foreground_width
    blended_portion = cv.addWeighted(foreground,
                alpha,
                background[start_y:end_y, start_x:end_x,:],
                1 - alpha,
                0,
                background)
    background[start_y:end_y, start_x:end_x,:] = blended_portion
    cv.imshow('composited image', background)

    cv.waitKey(10000)