Help developing an image frame sequence generator

Hi all,

I am doing a project where I have to create frames of images, to show a track path of an object and detect it. The end goal of my code is to create a line that shows the track path of the object as it moves and a box to detect the object at it's final position on the image (original image and desired output image that I would like is shown as an example).

In order to do this, I need help with generating the frames with different object positions. I have already created an object from an array (using the zeros function) with a set intensity value and have overlayed it on to the original background image (using imadd(image, object)). I have different frames with the object at different positions. Any idea, how I can show a streak/line to show the track path of the object?

I would really appreciate any help with this.

Kind regards,

Vanessa

Original frame:

Desired image output:

Answer 1

[Will Nitsch]

Since you have all of the object positions (I assume you know the sequential order of each position as well), you can use Bresenham's line drawing algorithm. Here is a file-exchange submission. This is a well implemented algorithm but the author forgot to terminate a couple of lines with ';', so be sure to add those unless you want tons of stuff printed to the command window. https://www.mathworks.com/matlabcentral/fileexchange/28190-bresenham-optimized-for-matlab

To do this, first get your position coordinates as the (x,y) pixel indices. Then, for each iteration of the sequence (from 1 -> 2, from 2 -> 3, from 3 -> 4, etc.), just call the Breshenam algorithm to generate the list of x and y coordinates associated with the line between each set of two points. For instance, your workflow would go something like this:

Make a red line between points, given two locations '(x1,y1)' and '(x2,y2)':

>> [x y]=bresenham(x1,y1,x2,y2);

>> for i = 1:length(x)

>> Iin(y(i),x(i),1) = 255;

>> Iin(y(i),x(i),2) = 0;

>> Iin(y(i),x(i),3) = 0;

>> end

[Vanessa]

Thank you so much! I will give this a try.