请问matlab中这段对视频的预处理代码实现了什么样的效果呢？

请问matlab中这段对视频的预处理代码实现了什么样的效果呢？

disp('input video');) E: Y9 ?% o5 t8 E( t& k
avi= VideoReader('D:\MATLAB\SampleVideo.Mp4');
" i6 {/ ~. a5 W9 K, WnumFrames = avi.NumberOfFrames; %读取视频的帧数9 c# A$ P$ s8 U, ]# Y/ N6 h# m
vidHeight = avi.Height;; I& u% m" z& U
vidWidth = avi.Width;5 k  n$ R$ d& N
for i = 1 : numFrames, n8 a: M# `: c- ^+ J; H/ `
frame = read(avi,i); %读取每一帧) K* P$ d& M4 W
imshow(frame); %显示每一帧( D3 }' y6 \2 ]. P6 Q7 T& s
imwrite(frame,strcat(num2str(i),'.jpg'),'jpg'); %保存每一帧8 k9 a3 `# _& [0 m0 W( V) }. S
end
5 y; Q! H/ F0 l9 _mov(1:numFrames) = ...
; b8 _! \( i, i0 m# h+ Vstruct('cdata', zeros(vidHeight, vidWidth, 3, 'uint8'),...2 B$ [7 S" c( r, V8 G' R: U
'colormap', []);
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5 S, {0 _# K; ~% Y( D  F1 Jfor k = 1 : numFrames: I3 s6 I$ C- v3 Q
mov(k).cdata = read(avi, k);
4 w# A% J$ ~6 t7 _
* r+ t5 Z& Y, j" Q' `4 cend
5 y. v( T( r1 w6 K- |video={mov.cdata};$ }( F$ {% s+ T( f2 h
for a = 1:length(video)& T9 V6 W, e9 j. T+ |+ h
imagesc(video{a});
, S4 w6 A3 e3 E0 I/ p' ~axis image off
9 c' N% `8 e/ P9 C9 S' sdrawnow; ( ~# t; x- H+ w% u# w
end;
6 i/ {, Q) y' u2 {0 Idisp('output video');

谢谢