Question

使用Matlab 2018。

我有一组图像，其中绘制了大量ROI。对于图片，还定义了一个位掩码。我想找到位掩码为1的每个ROI的部分（分数或百分比）。以下代码可以工作，但是速度很慢。（对于8张图像大约需要1分钟，每张图像的投资回报率为80）。必须有更聪明的方法来做到这一点。

数据是这样提供的：我感兴趣的图像部分位于两个“环”之间。这些环是手动绘制的。对于每个环，依次记录80点，顺时针旋转。

内圈的数据存储为InnerX（n，Im），InnerY（n，Im），其中n表示点的编号，Im是图像编号（多张图像的数据在同一位置处理时间）。

OuterX和OuterY相似。每个ROI由内环中的两个连续点和外环中的两个相应点定义。


Score = zeros(size(InnerX));

%Loop over the different images
for i = 1:size(InnerX, 2)
    %Loop over all points in this ring
    %The points are ordered, so that consecutive points in Inner
    %and Outer ring form a ROI

    for n = 1:size(InnerX,1)

        %if statement to take care of the last point
        if(n == size(InnerX, 1))
            X = [InnerX(n,i), InnerX(1,i) OuterX(1,i) OuterX(n,i)];
            Y = [InnerY(n,i), InnerY(1,i) OuterY(1,i) OuterY(n,i)];
        else
            X = [InnerX(n,i), InnerX(n+1,i) OuterX(n+1,i) OuterX(n,i)];
            Y = [InnerY(n,i), InnerY(n+1,i) OuterY(n+1,i) OuterY(n,i)];
        end

        %Calculate the integer numbers of the range of all pixels that could
        %potentially overlap
        xmin = floor(min(X)); 
        ymin = floor(min(Y)); 
        xmax = floor(max(X)); 
        ymax = floor(max(Y));

        %Create shape
        TotalArea = polyshape(X, Y);

        %Loop over all pixels within the range
        %For each pixel calculate the overlap with the ROI
        %Multiply with the bitmask score for that pixel (0 or 1)
        for x = xmin:xmax
            for y = ymin:ymax
                ROI = polyshape([x x x+1 x+1], [y y+1 y+1 y]);
                polyout = intersect(TotalArea, ROI);
                Score(n,i) = Score(n,i) + Bitmap(y,x,i) .* polyout.area;
            end
        end

        %Divide by the area of the ROI
        Score(n,i) = Score(n,i) / TotalArea.area;
    end
end


The results coming out of this seem accurate (correct shape, all numbers between 0 and 1), but as said, this code is rather slow.

Thanks in advance.

计算ROI和位掩码之间重叠的更快方法

0 个答案: