How to insert image in MatLab

674 次查看（过去 30 天）
Emily Smith
Emily Smith 2016-10-3
评论： DGM 2024-11-15，6:29
I want to insert an image at (0,0) on a plot. How would I do this and how can I determine the size? And also do I need to convert the image to a png?
Thanks!

请先登录，再回答此问题。

回答（3 个）

Jakub Rysanek
Jakub Rysanek 2016-10-4
imread() can import whole bunch of graphical data types, including .jpg and .png. Conversion to .png, as you ask, is not necessary.
img = imread('filename.png');
image(img);
To alter the size/positioning of the image within your figure, you can touch the underlying axes object:
x = 0;
y = 0;
width = 0.5;% measured relative to the figure width
height = 0.5;% measured relative to the figure height
set(gca,'units','normalized','position',[x y width height])
Gareth Thomas
Gareth Thomas 2016-10-3
DGM
DGM 2023-2-20
编辑：DGM 2023-2-20
Ran in:
There are a lot of views on this vague question, so maybe I should put an answer here that might be more complete.
% some data in a plot
t = linspace(0,pi,100);
y = sin(2*t);
plot(t,y); hold on; grid on
% an image
FG = imread('cameraman.tif');
% i'm going to expand the image to make sure it's RGB
% this avoids issues dealing with colormapped objects in the same axes
if size(FG,3) == 1
FG = repmat(FG,[1 1 3]);
end
% the origin of an image is the NW corner
% so in order for both the plot and image to appear right-side up, flip the image
FG = flipud(FG);
% insert an image in a particular region in the current axes
% this uses image(); similar can be done with imshow()/imagesc()
image(FG,'xdata',[0 pi/4],'ydata',[0 pi/4])
axis equal
To find the size of an image, use size(), or see this thread.
To save an image, use imwrite(). To save a screenshot of a figure as an image, use saveas(), exportgraphics(), or a combination of getframe(), frame2im(), and imwrite(). Again, if the image you want to save is already in the workspace, save it using imwrite(), not by taking a screenshot of it.
% save a screenshot of the plot with overlaid image
saveas(gcf,'myplot.png')
% save a copy of the modified foreground image
imwrite(FG,'mycman.png')
Avoid using JPG for anything, especially saving figures.
  5 个评论
显示 3更早的评论
Walter Roberson
Walter Roberson 2024-11-14，19:40
Check to see if it is something-by-something-by-2 . If it is, then likely it is grayscale + alpha.
Gray = Grayscale_plus_alpha(:,:,1);
Alpha = im2double(Grayscale_plus_alpha(:,:,2));
image(Gray, 'AlphaData', Alpha)
DGM
DGM 2024-11-15，6:29
You might be able to save it as an SVG, but even with third-party SVG import tools, only a subset of the possible object types in an SVG file can be read.
As Walter points out, image() (which is what's used internally by imagesc() and imshow()) only accepts MxN arrays (of numeric or logical class) or MxNx3 arrays (of float or unsigned integer numeric class). It's possible to get MxNx4 or MxNx1xF arrays from imread() without any special syntax or options.
If you can attach the image file and/or the code used to replicate the issue, we can tell you why.

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Convert Image Type 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by