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Date: 2019-5-2

前言

    目标跟踪一直是计算机视觉领域中一个比较重要的研究课题，实际应用较多。本文主要采用背景差分法、帧差法和光流法实现简单的目标跟踪系统。

1、参考

2、Matlab实现（部分）

function d = tracking(video)pixels = video;nFrames = size(pixels, 4);rows = size(pixels, 1);cols = size(pixels, 2);% 转换成灰度图像for i = 1 : nFrames    pixel(:, :, i) = (rgb2gray(pixels(:,:,:,i)));endw_history = 0;for i = 2 : nFrames    d(:, :, i) = (abs(pixel(:,:,i) - pixel(:,:,i-1)));    bw(:, :, i) = im2bw(d(:, :, i), 0.2);    % 寻找上下边界    cou=1;    for h = 1:rows        for w = 1:cols            if bw(h, w, i) > 0.5                bottomEdge = h;                if cou == 1                    topEdge = bottomEdge;                end                cou = cou+1;                break;            end        end    end    % 寻找左右边界    coun=1;    for w = 1:cols        for h = 1:rows            if bw(h, w, i) > 0.5                if i <= 2/3*nFrames                    if abs(w-w_history) < 72.1                         rightEdge = w;                    else                        rightEdge = w_history+1;                    end                else                    if abs(w-w_history) < 62.5                         rightEdge = w;                    else                        rightEdge = w_history+1;                    end                end                if coun == 1                    leftEdge = rightEdge;                    coun = coun+1;                end                w_history = rightEdge;                break;            end        end    end    % 矩形框生成    wd = rightEdge-leftEdge;    hg = bottomEdge-topEdge;        widt = wd/2;    heit = hg/2;    cenx = leftEdge+widt;    ceny = topEdge+heit;    % 显示并标记    figure(1);    imshow(pixels(:, :, :, i), []);    hold on    rectangle('Position',[cenx-10 topEdge 20 hg], 'EdgeColor', 'r', 'LineWidth', 2);    plot(cenx, ceny, 'ko', 'MarkerFaceColor', 'r', 'MarkerSize', 10, 'LineWidth', 2);            text(1, 15, sprintf('跟踪视频：%d帧', i), 'FontWeight', 'Bold', 'Color', 'r');    hold offend

3、实验效果图

3.1、背景差分法实现目标跟踪

3.2、帧差法实现目标跟踪

3.3、光流法实现目标跟踪

4、更多知识

4.1、matlab GUI中imshow刷新问题

在matlab 2012b中GUI中显示视频是可以正常显示的，但是在更高版本的2014b中，在axes中不能刷新出视频中每帧数据，只能显示出来最后一帧。

help drawnow

drawnow Flush pending graphics events.

drawnow “flushes the event queue” and updates the figure window.

drawnow causes figure windows and their children to update and

flushes the system event queue. Any callbacks generated by incoming

events - e.g. mouse or key events - will be dispatched before

drawnow returns.

drawnow(‘EXPOSE’) causes only graphics objects to refresh, if

needed. It does not allow callbacks to execute and does not

process other events in the queue.

drawnow(‘UPDATE’) causes only non-graphics objects to refresh, if

needed. It does not allow callbacks to execute and does not

process other events in the queue.

drawnow is called implicitly upon returning to the MATLAB prompt and

when executing the following functions:

figure

getframe

ginput

input

keyboard

pause

waitfor

waitforbuttonpress

作者：SoaringLee_fighting

THE END!