如何使用ImageMagick替换图像中的白色矩形？

问题描述

概述：

第一张照片是我的原始照片。在这里，我想用另一个图像替换显示的白色矩形。

The first picture is my original image. Here I want to replace the white rectangle shown with another image.

我的方法：

我有使用 floodfill 创建了一个掩码图像，它看起来像：

I have created a mask image using floodfill and it looks as:

问题：

现在我想获得第二张图像中矩形的距离或坐标，这样我就可以使用这些坐标在第一张图像的顶部叠加新图像（原始图像）在这里。

Now I would like to get the distance or co-ordinates of the rectangle in the second image so that I can use those co-ordinates to overlay a new image on top of the first (original image) here.

我有点想法使用ImageMagick的形态运算符，但不知道我怎么做。

I got a little idea to use ImageMagick's chebyshev morphology operator, but don't know how I can do that.

推荐答案

我认为你可以用as非常准确地定位形状实现阈值，如下所示：

I think you can locate the shape pretty accurately with a simple threshold, like this:

convert image.jpg -threshold 90% result.jpg

然后你可以像这样做一个Canny边缘检测：

and you can then do a Canny edge detection like this:

convert image.jpg -threshold 90% -canny 0x1+10%+30% result.jpg

接下来的事情我会正在使用 -trim 函数来查找修剪框坐标，如下所示：

The next things I would be looking at are, using the -trim function to find the trim box coordinates, like this:

convert result.jpg -format "%@" info:
320x248+152+40

我在下面用红色标记了。

I have marked that on in red below.

如果你真的想做修剪，请使用：

If you actually want to do the trim, use this:

convert result.jpg -trim result.jpg

此外，还有偏斜角度

convert result.jpg -deskew 40 -format "%[deskew:angle]" info:
-0.111906

霍夫线检测也可能对您有效：

A Hough line detection may also be effective for you like this:

convert image.jpg -threshold 90% -canny 0x1+10%+30%      \
    \( +clone -background none                           \
              -fill red -stroke red -strokewidth 2       \
              -hough-lines 5x5+80 -write lines.mvg       \
    \) -composite hough.png

文件 lines.mvg 包含您要查找的4行

And the file lines.mvg contains the 4 lines you are looking for

# Hough line transform: 5x5+80
viewbox 0 0 640 360
line 449.259,0 474.432,360  # 90
line 0,72.5604 640,27.8072  # 143
line 0,293.098 640,248.344  # 187
line 153.538,0 178.712,360  # 153

有点懒，我不想解决交叉点那些线，所以我想我也让ImageMagick这样做 - 通过使用Morphology寻找这样的Line Junctions：

Being a bit lazy, I didn't feel like solving for the intersections of those lines, so I thought I'd let ImageMagick do that too - by using Morphology to look for Line Junctions like this:

convert image.jpg -threshold 90% -canny 0x1+10%+30%                        \
  \( +clone -background none -fill red -stroke red -hough-lines 5x5+80 \)  \
     -composite -fuzz 50% -fill black -opaque white                        \
     -morphology HMT LineJunctions hough.png

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