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');, _* m. i4 v6 q5 m/ z1 v
avi= VideoReader('D:\MATLAB\SampleVideo.Mp4');
# ?1 z6 C1 \' L) N2 R% A/ ?numFrames = avi.NumberOfFrames; %读取视频的帧数$ P  L6 Y7 B* k# [, a1 B
vidHeight = avi.Height;
+ J! @6 Q( N$ {$ p, f3 R  OvidWidth = avi.Width;& b3 D$ d  c3 q. P$ r- R
for i = 1 : numFrames
; a/ m) S6 l% Q8 f5 {0 {9 Y" Sframe = read(avi,i); %读取每一帧" b, t! b, ]5 K
imshow(frame); %显示每一帧5 T# H, a) f6 L; n! C4 J
imwrite(frame,strcat(num2str(i),'.jpg'),'jpg'); %保存每一帧+ [* S/ l  c7 l! e7 P
end+ [, }. O( d+ m, F+ W9 {
mov(1:numFrames) = ...
) }" ^* A! M) J9 }0 }( |4 _! Wstruct('cdata', zeros(vidHeight, vidWidth, 3, 'uint8'),...6 D, g/ H- `1 u- W( z! S: u
'colormap', []);3 A" L* @; \( J+ U4 o$ i$ g
3 p% R6 }0 q4 i# E' \. ~" a# d
for k = 1 : numFrames
# G, Y0 \1 U7 a- a" w9 B- k. Bmov(k).cdata = read(avi, k);
' D- w- X6 U/ F/ `8 }7 c* }* Q4 ?! J. q+ p  @6 G2 t- s
end% M  W( c3 q5 j1 U) K* i3 i9 R
video={mov.cdata};7 H  u" Z4 p" @5 _0 h2 N* l
for a = 1:length(video)
* ~: L5 W8 x1 Nimagesc(video{a}); ( y, S% x5 g# ^6 o- v( D
axis image off 3 Y% @8 V5 a, H+ d8 V/ d# R. g! Q
drawnow;
8 D, s3 e# d7 @9 `, Y5 [" yend;
; p7 d$ X. [$ Q$ [; Ydisp('output video');

谢谢