问题

抱歉，我只会为您提供代码的翻译部分：

提前说明一下，我无法提供一个最小可行示例，因为我不知道该怎么做。
我有一个二进制掩模在owin中。基本上，我的数据包含五个不同大小的成团点。我试图获取它们的面积。

据我所知，伟大的spatstat包没有此功能。

首先，我将owin转换为raster图层，使用`raster_mask <- raster(as.im(dd))`。
之后，我按如下方式检测成团点：
```R
library(igraph)
clusters <- clump(raster_mask)

现在我可以绘制clusters，每个成团点都有自己的颜色。
就我所理解的而言，area(clusters)函数应该提供它们的面积，但我收到了一个警告

该函数仅适用于具有经度/纬度坐标的Raster*对象

为了进行控制，我使用了crs(clusters)，看到了一个NA。所以我用以下代码设置了crs：

crs(clusters) <- "+proj=utm +zone=32 +ellps=GRS80 +units=m +no_defs +type=crs"

现在我有一个CRS，但仍然收到相同的警告。此时我的数据如下所示：

> print(areas)
class      : RasterLayer 
dimensions : 135, 129, 17415  (nrow, ncol, ncell)
resolution : 0.9790567, 1.224028  (x, y)
extent     : 490715.5, 490841.8, 5429337, 5429502  (xmin, xmax, ymin, ymax)
crs        : +proj=utm +zone=32 +ellps=GRS80 +units=m +no_defs +type=crs 
source     : memory
names      : layer 
values     : 1.198393, 1.198393  (min, max)

所以我尝试将CSR更改为longlat。
在寻找成团点之前，使用以下代码并收到一个错误。

> crs(raster_mask) <- "+proj=utm +zone=32 +ellps=GRS80 +units=m +no_defs +type=crs"
> raster_mask <- projectExtent(raster_mask, "+proj=longlat +datum=WGS84")
> plot(raster_mask)
Error in .plotraster2(x, col = col, maxpixels = maxpixels, add = add,  : 
  no values associated with this RasterLayer

我可能完全错误了。如果有人有提供最小工作示例的想法，我将不胜感激。我希望有人能帮助我从二进制图像掩模中获取面积。欢迎任何有关定位的帮助！

提前感谢您！

<details>
<summary>英文:</summary>

Ahead, I&#39;m not able to provide a minimum working example since I don&#39;t know how.
I have an binary mask in an owin. Basically, my data contains five clumped dots of different size. I try to get their area.

As far as I know, the great spatstat package has no function for this.

First, I convert the owin to an raster layer with `raster_mask &lt;- raster(as.im(dd))`.
After that, I detect the clumps as follows:

library(igraph)
clusters <- clump(raster_mask)

Now I can plot `clusters` with each of the five clusters in its own colour. 
And as far as I understand the function `area(clusters)` should provide me with their area, but instead I receive an warning 
>This function is only useful for Raster* objects with a longitude/latitude coordinates

For control, I use `crs(clusters)` and see an NA. So I set crs with

crs(clusters) <- "+proj=utm +zone=32 +ellps=GRS80 +units=m +no_defs +type=crs"

Now I have an CRS, but receive the same warning. My data at this points looks as follows:

> print(areas)
class : RasterLayer
dimensions : 135, 129, 17415 (nrow, ncol, ncell)
resolution : 0.9790567, 1.224028 (x, y)
extent : 490715.5, 490841.8, 5429337, 5429502 (xmin, xmax, ymin, ymax)
crs : +proj=utm +zone=32 +ellps=GRS80 +units=m +no_defs +type=crs
source : memory
names : layer
values : 1.198393, 1.198393 (min, max)

So I try to change the CSR to longlat.
Before I search for the clumps, using this code and receiving an error.

> crs(raster_mask) <- "+proj=utm +zone=32 +ellps=GRS80 +units=m +no_defs +type=crs"
> raster_mask <- projectExtent(raster_mask, "+proj=longlat +datum=WGS84")
> plot(raster_mask)
Error in .plotraster2(x, col = col, maxpixels = maxpixels, add = add, :
no values associated with this RasterLayer

I might be completely wrong. If someone has an idea how to provide a minimal working example I would be glad to provide it. I hope someone could help me to receive areas from an binary image mask. Any help for orientation is welcome!

Thank you ahead!


</details>


# 答案1
**得分**: 2

在`spatstat`中，您可以使用`connected`函数来识别连接的组件。

如果`dd`是您的原始二进制掩模（类别为`"owin"`的对象），那么`P <- connected(dd)`将返回一个具有分类值的像素图像`P`。每个分类值对应一个连接的组件。对此图像进行绘制，`plot(P)`，将显示原始数据的彩色版本，其中每个连接的组件都用不同的颜色填充。

您可以从中计算每个连接的组件的面积。一种简洁的方法是将连接的组件视为镶嵌中的瓷砖。
示例：

```R
library(spatstat)
## 创建示例数据
dd <- dilation(redwood, 0.5, polygonal=FALSE)
## 找到连接的组件
P <- connected(dd)
## 转换为镶嵌
B <- tess(image=P)
## 计算每个瓷砖的面积
answer <- tile.areas(B)

library(spatstat)
## create example data
dd <- dilation(redwood, 0.5, polygonal=FALSE)
## find connected components
P <- connected(dd)
## convert to a tessellation
B <- tess(image=P)
## compute area of each tile
answer <- tile.areas(B)