how to color circles on an image? the color should varies with the variation of the serial data

Question

marc kahwaji 2014-8-1

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/144329-how-to-color-circles-on-an-image-the-color-should-varies-with-the-variation-of-the-serial-data

回答： marc kahwaji 2014-8-2

i have a microcontroller connected to a force sensor and sending serial data. i'm putting these data in a matrix i need to draw circles to represent the force sensors on an image and color them the color should varies with the values of the serial data. example if the value in the matrix is 46 the color of the circle should varies from blue to red could someone help me please

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

William Frane 2014-8-1

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/144329-how-to-color-circles-on-an-image-the-color-should-varies-with-the-variation-of-the-serial-data#answer_147128

在 MATLAB Online 中打开

A simple way to do this is to plot large circular data markers on top of the image (using the hold command). Something along the lines of:

% Display image
hold on
% Iterate through all the sensors
% Get position and color for each sensor
currentColor = ConvertValueToColor(currentSensorValue);
plot(currentX, currentY, 'Marker', 'o', 'MarkerSize', 30, 'MarkerFaceColor', currentColor, 'MarkerEdgeColor', 'none');

If you normalize your sensor data such that they lie between 0 and 1, you could use something like this to vary the color:

function out = ConvertValueToColor(in) % Picks a color between blue and red
% Assumes 'in' is between 0 and 1
out = (1-in)*[0 0 1] + in*[1 0 0];

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 2

Image Analyst 2014-8-1

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/144329-how-to-color-circles-on-an-image-the-color-should-varies-with-the-variation-of-the-serial-data#answer_147132

Another way is to use the rectangle() function to draw circles. Kind of crazy, but yes, rectangle() can draw circles(). I've always wondered why they just don't have a ellipse() or circle() function. But no, that would be too easy and intuitive.