error in corr2 function in matlab

4 次查看（过去 30 天）
SHOBA MOHAN
SHOBA MOHAN 2018-1-14
评论： Walter Roberson 2021-2-5
I have created templates of number and symbols and want to match the vehicle number plate with template using corr2 function. While running the code got the following error
Error using corr2
Expected input number 1, A, to be two-dimensional.
MAtlab code for template creation
%CREATE TEMPLATES
one=imread('1.png');
one=imresize(one,[42 24]);
two=imread('2.png');
two=imresize(two,[42 24]);
three=imread('3.png');
three=imresize(three,[42 24]);
four=imread('4.png');
four=imresize(four,[42 24]);
five=imread('5.png');
five=imresize(five,[42 24]);
zero=imread('0.png');
zero=imresize(zero,[42 24]);
sign=imread('sign.png');
sign=imresize(sign,[42 24]);
number=[one two three four five zero ];
character=[number sign];
NewTemplates1=mat2cell(character,42,[24 24 24 24 24 24 24], 3);
save ('NewTemplates1','NewTemplates1')
clear all
matlab code for reading the letter
load NewTemplates1 % Loads the templates of characters in the memory.
snap=imread('untitled.png');
snap=imresize(snap,[42 24]); % Resize the input image so it can be compared with the template's images.
comp=[ ];
for n=1:length(NewTemplates1)
sem=corr2(NewTemplates1{1,n},snap); % Correlation the input image with every image in the template for best matching.
comp=[comp sem]; % Record the value of correlation for each template's character.
end
vd=find(comp==max(comp)); % Find the index which correspond to the highest matched character.
%*-*-*-*-*-*-*-*-*-*-*-*-*-
% Accodrding to the index assign to 'letter'.
% Alphabets listings.
if vd==1
letter='1';
elseif vd==2
letter='2';
elseif vd==3
letter='3';
elseif vd==4
letter='4';
elseif vd==5
letter='5';
elseif vd==6
letter='0';
elseif vd==7
letter='sign';
end
For kind information: The size of individual component in template is 42x24x3 uint8 and the input image also same dimension. Please provide the suggestion to do further.
  3 个评论
显示 1更早的评论
wiqar Ahmad
wiqar Ahmad 2021-2-5
can you please share me the correct code?
Will be Thankfull
Walter Roberson
Walter Roberson 2021-2-5
As discussed below: use rgb2gray() before doing the corr2.

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Walter Roberson
Walter Roberson 2018-1-14
You are asking corr2 to operate on a 42 x 24 x 3 array. That is a 3d array which is not something that corr2 can use. Your array is 3d because you are carrying through rgb. You need to do each plane independently, or you need to switch to greyscale, or you need to reshape so that you are working in 2d.

更多回答（1 个）

John BG
John BG 2018-1-15
编辑：John Kelly 2018-1-16
Hi Shoba Mohan
this is John BG <mailto:jgb2012@sky.com jgb2012@sky.com>
Since the actual size of the input images, both the references and the unknown input to correlate with the references, I have omitted the imresize lines.
With that, one way to have your code running is as follows:
clear all;clc
one=imread('1.png');one=one(:,:,1);
% one=imresize(one,[42 24]);
two=imread('2.png');two=two(:,:,1);
% two=imresize(two,[42 24]);
three=imread('3.png');three=three(:,:,1);
% three=imresize(three,[42 24]);
four=imread('4.png');four=four(:,:,1);
% four=imresize(four,[42 24]);
five=imread('5.png'); five=five(:,:,1);
% five=imresize(five,[42 24]);
zero=imread('0.png');zero=zero(:,:,1);
% zero=imresize(zero,[42 24]);
sign=imread('sign.png');sign=sign(:,:,1);
% sign=imresize(sign,[42 24]);
number=[one two three four five zero ];
character=[number sign];
NewTemplates1=zeros([size(one) 7]);
% mat2cell(character,42,[24 24 24 24 24 24 24], 3);
NewTemplates1(:,:,1)=one;
NewTemplates1(:,:,2)=two;
NewTemplates1(:,:,3)=three;
NewTemplates1(:,:,4)=four;
NewTemplates1(:,:,5)=five;
NewTemplates1(:,:,6)=zero;
NewTemplates1(:,:,7)=sign;
save ('NewTemplates1','NewTemplates1')
clear all
load NewTemplates1 % Loads the templates of characters in the memory.
snap=imread('untitled.png');snap=snap(:,:,1);
% snap=imresize(snap,[42 24]); % Resize the input image so it can be compared with the template's images.
comp=[ ];
[sz1 sz2 sz3]=size(NewTemplates1);
for n=1:sz3
sem=corr2(NewTemplates1(:,:,n),snap); % Correlation the input image with every image in the template for best matching.
comp=[comp sem]; % Record the value of correlation for each template's character.
end
[vd,col,q]=find(comp==max(comp)); % Find the index which correspond to the highest matched character.
%*-*-*-*-*-*-*-*-*-*-*-*-*-
% Accodrding to the index assign to 'letter'.
% Alphabets listings.
if vd==1
letter='1';
elseif vd==2
letter='2';
elseif vd==3
letter='3';
elseif vd==4
letter='4';
elseif vd==5
letter='5';
elseif vd==6
letter='0';
elseif vd==7
letter='sign';
end
Now the code doesn't return error but the correlation doesn't catch some of the samples I have used.
Wouldn't it be reasonable to consider already working MATLAB application for car plate recognition, like:
https://uk.mathworks.com/matlabcentral/fileexchange/44088-car-license-plate-reader
.
thanks in advance for time and attention
John BG
<mailto:jgb2012@sky.com jgb2012@sky.com>
  5 个评论
显示 3更早的评论
Walter Roberson
Walter Roberson 2018-1-15
The rules about license plates on the front of cars are provincial in Canada, so some provinces require them and some do not.
John BG
John BG 2018-1-16
Thanks again for this other clarification :)

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Region and Image Properties 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by