matlab将图形对象渲染到内存中的位图 [英] matlab render graphical objects to a bitmap in memory

问题描述

这应该是非常简单的我认为但我无法正确...

This is supposed to be very simple I think but I can't get it right...

我在图中绘制了几个图形对象，现在我想要图中的位图，用于维护对象上的位置和图形的尺寸。

I plot several graphical objects in a figure and now I want a bitmap of the figure, that maintains the position on the objects and the dimensions of the figure.

举一个非常简单的例子，如果我在坐标中绘制2个点（ 0,0）和（200,200）我希望渲染输出一个大小为（200,200）的矩阵，其中像素（0,0）和（200,200）的灰度级为255，其余像素为零（这是每像素8位灰度的情况虽然3我更喜欢颜色位图，它将反映对象的颜色，如原始图中所示）

To give a very simple example, if I plot 2 points in coordinates (0,0) and (200,200) I expect the rendering to output a matrix of size (200,200) where pixels (0,0) and (200,200) have a gray level of 255 and the rest of the pixels are zeroed (this is in case of a 8-bit per pixel grayscale though 3I prefer a color bitmap that will reflect the colors of the objects as appear in the original figure)

谢谢

推荐答案

为了回答我自己的问题，这就是我用图形对象将图形渲染到内存中的位图并保持比例的方法：我使用 getFrame ，然后将结果调整为轴的大小。这里是：

To answer my own question, this is what I did to render a figure with graphical objects to a bitmap in memory and keep it in scale: I used getFrame and then resized the result to the size of the axes. Here goes:

% plot stuff on the current axes, then...

set(gca, 'ydir', 'reverse');
xLim = get(gca, 'XLim');
yLim = get(gca, 'YLim');
rendered = getframe(gca);
imageMat = imresize(rendered.cdata, [floor(yLim(2)), floor(xLim(2))]);

此处图像被采样两次，这在处理时间方面效率低，并且图像质量稍差。为了我的目的，它还可以，但单样本解决方案仍然很好......

Here the image is sampled twice which is both inefficient in terms of processing time and gives a somewhat degraded image. For my purposes it's ok but still a single-sample solution would be nice...

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