Technical Discussions related to Image Processing (image coding, compression, digital effects, mpeg, etc)
dear all members
I am trying to find rate of difference or rate of similarity of two
Images.
anyone can give me any Idea ?
for example :
if we have 2 Image : im1.jpg and im2.jpg
----------------------------------
f1=imread('im1.jpg');
f2=imread('im2.jpg');
F1=fft2(f1);
F2=ff2(f2);
similarity(f1,f2)=?
-------------------------------
How can I compare this two Fouriers?
How can I find rate of similarity of this two image?
the expected results are something like this:
similarity(f1,f2)=99.9
similarity(f1,f3)=98.7
similarity(f1,f4)=34.5
....
Thanks
______________________________perhaps you may try image subtraction of image difference operations...if
t=
he images are of the same size then these image calculations=A0 may determi=
ne the diferences you are after...hope this helps
cheers
--- On Thu, 7/1/10, mohammad <m...@yahoo.com> wrote:
From: mohammad <m...@yahoo.com>
Subject: [imagedsp] How to detection similarity of two Image
To: i...@yahoogroups.com
Received: Thursday, 7 January, 2010, 5:44 AM
dear all members
I am trying to find rate of difference or rate of similarity of two
Images.
anyone can give me any Idea ?
for example :
if we have 2 Image : im1.jpg and im2.jpg
----------------------------------
f1=3Dimread('im1.jpg');
f2=3Dimread('im2.jpg');
F1=3Dfft2(f1);
F2=3Dff2(f2);
similarity(f1,f2)=3D?
-------------------------------
How can I compare this two Fouriers?
How can I find rate of similarity of this two image?
the expected results are something like this:
similarity(f1,f2)=3D99.9
similarity(f1,f3)=3D98.7
similarity(f1,f4)=3D34.5
....
Thanks=20
_____________________________________
______________________________You can also compute the correlation between these two images and look for the picks; the same which we apply in template matchings and so forth. bests
Hello mr. mohammad for similarity evaluation you can calculate the corrolation coeficient of two images using this command: corr2(f1,f2) this will give you anumber in the interval of [0 1] 1 shows full similarity and 0 shows no similarity. you also can comper the histogram of images or simply the squar error between to images as : Error=sum(sum((f1-f2).^2))______________________________
Dear, Mehrnaz
Thanks for ur Idea.
I tried both of the your seggustion ( Corr2( ) , and Sum(sum( )).
but these method do the similarity estimation with pixel-by-pixel. and they are
not robust against a bit modification .
I need an effective Discriminative Invariant Features of Image that be robust
against small modification for example rotation.
Thanks again ,
plz Give me your Idea , If you have another one.
In my opinion , there is need to robust feature in frequency domain !
for example if we have 3 blocks:
A1=
248 253 251 253
245 252 250 253
245 252 251 254
248 252 252 254
A2=
252 252 251 251
252 252 251 251
252 252 252 252
253 252 252 252
D1=
229 229 229 229
229 229 229 229
229 0 229 229
229 229 229 229
D2=
1 200 3 0
80 2 30 50
100 50 200 90
0 2 70 1
we have to be able to find percentage of similarity of these blocks.
in this example -
the result has to be something like these:
1- similarity(A1,A2) -----> 99.99%
2- similarity(A1,D1) -----> 80%
3- similarity( A1,D2) --------> 10%
Best Regards
Mohammad Akbarpour Sekeh
Student of PhD in Computer Forensic -IFD area
Faculty of Computer Science and Information system
University Technology Malaysia
81310 UTM Skudai, Johor, Malaysia
Cell-Phone:+60-127890645
________________________________
From: mehrnaz fani <f...@gmail.com>
To: mohammad <m...@yahoo.com>
Cc: i...@yahoogroups.com
Sent: Fri, 8 January, 2010 14:12:51
Subject: Re: [imagedsp] How to detection similarity of two Image
Hello mr. mohammad
for similarity evaluation
you can calculate the corrolation coeficient of two images
using this command: corr2(f1,f2)
this will give you anumber in the interval of [0 1]
1 shows full similarity and 0 shows no similarity.
you also can comper the histogram of images
or simply the squar error between to images as :
Error=sum(sum((f1-f2).^2))
______________________________Try xcorr2(), then=E2=80=A6 It gives a peak at a location depending on the = amount of a shifting perturbation. If you have rotative or scaling perturba= tions, then you may try multi resolution approaches together with KLT (for = alignment). If you have scaling or rotation, so does the frequency domain. = Please let us know if you find a robust feature there. =20 Best, =20 Omer =20 From: i...@yahoogroups.com [mailto:i...@yahoogroups.com] On Behalf = Of mohammad akbarpour Sent: Friday, January 08, 2010 9:30 AM To: mehrnaz fani Cc: i...@yahoogroups.com Subject: Re: [imagedsp] How to detection similarity of two Image =20 Dear, Mehrnaz Thanks for ur Idea. I tried both of the your seggustion ( Corr2( ) , and Sum(sum( )). but these method do the similarity estimation with pixel-by-pixel. and they= are not robust against a bit modification . I need an effective Discriminative Invariant Features of Image that be robu= st against small modification for example rotation. Thanks again ,=20 plz Give me your Idea , If you have another one.=20 In my opinion , there is need to robust feature in frequency domain ! for example if we have 3 blocks:=20 A1=3D=20 248 253 251 253=20 245 252 250 253=20 245 252 251 254=20 248 252 252 254=20 A2=3D=20 252 252 251 251=20 252 252 251 251=20 252 252 252 252=20 253 252 252 252=20 D1=3D=20 229 229 229 229=20 229 229 229 229=20 229 0 229 229=20 229 229 229 229=20 D2=3D=20 1 200 3 0=20 80 2 30 50=20 100 50 200 90=20 0 2 70 1=20 we have to be able to find percentage of similarity of these blocks.=20 in this example -=20 the result has to be something like these:=20 1- similarity(A1,A2) -----> 99.99%=20 2- similarity(A1,D1) -----> 80%=20 3- similarity( A1,D2) --------> 10%=20 =20 Best Regards Mohammad Akbarpour Sekeh Student of PhD in Computer Forensic -IFD area Faculty of Computer Science and Information system University Technology Malaysia 81310 UTM Skudai, Johor, Malaysia Cell-Phone:+60-127890645 =20 =20 _____=20=20 From: mehrnaz fani <f...@gmail.com> To: mohammad <m...@yahoo.com> Cc: i...@yahoogroups.com Sent: Fri, 8 January, 2010 14:12:51 Subject: Re: [imagedsp] How to detection similarity of two Image Hello mr. mohammad for similarity evaluation you can calculate the corrolation coeficient of two images using this command: corr2(f1,f2) this will give you anumber in the interval of [0 1] 1 shows full similarity and 0 shows no similarity. you also can comper the histogram of images=20 or simply the squar error between to images as : Error=3Dsum(sum((f1-f2).^2)) ___________________________________________________________________
Dear All, Hello and Happy new year! For comapring two images or signals and for measuring rthe similarities, on= e of the=C2=A0approaches is to extract features and then, compare these fea= tures. As=C2=A0you mentioned these features are suppoosed to be invariant= =C2=A0with respect to tranlation, rotation, and scale. For example co-occur= rence matrix=C2=A0feature extraction method and Hu moments are widely used = for image analysis and classification. However, selecting the aproach reall= y depends on the application. You can find more about them in image process= ing and pattern recognition text books. I hope this would be helpful. Best regards, Alireza =C2=A0 ________________________________ From: mohammad akbarpour <m...@yahoo.com> To: mehrnaz fani <f...@gmail.com> Cc: i...@yahoogroups.com Sent: Fri, January 8, 2010 8:30:29 AM Subject: Re: [imagedsp] How to detection similarity of two Image =C2=A0=20 Dear, Mehrnaz Thanks for ur Idea. I tried both of the your seggustion ( Corr2( ) , and Sum(sum( )). but these method do the similarity estimation with pixel-by-pixel. and they= are not robust against a bit modification . I need an effective Discriminative Invariant Features of Image that be robu= st against small modification for example rotation. Thanks again ,=20 plz Give me your Idea , If you have another one.=20 In my opinion , there is need to robust feature in frequency domain ! for example if we have 3 blocks:=20 A1=3D=20 248 =C2=A0 =C2=A0 253 =C2=A0 =C2=A0 251 =C2=A0 =C2=A0 253=20 245 =C2=A0 =C2=A0 252 =C2=A0 =C2=A0 250 =C2=A0 =C2=A0 253=20 245 =C2=A0 =C2=A0 252 =C2=A0 =C2=A0 251 =C2=A0 =C2=A0 254=20 248 =C2=A0 =C2=A0 252 =C2=A0 =C2=A0 252 =C2=A0 =C2=A0 254=20 A2=3D=20 252 =C2=A0 =C2=A0 252 =C2=A0 =C2=A0 251 =C2=A0 =C2=A0 251=20 252 =C2=A0 =C2=A0 252 =C2=A0 =C2=A0 251 =C2=A0 =C2=A0 251=20 252 =C2=A0 =C2=A0 252 =C2=A0 =C2=A0 252 =C2=A0 =C2=A0 252=20 253 =C2=A0 =C2=A0 252 =C2=A0 =C2=A0 252 =C2=A0 =C2=A0 252=20 D1=3D=20 229 =C2=A0 =C2=A0 229 =C2=A0 =C2=A0 229 =C2=A0 =C2=A0 229=20 229 =C2=A0 =C2=A0 229 =C2=A0 =C2=A0 229 =C2=A0 =C2=A0 229=20 229 =C2=A0 =C2=A0 0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 229 =C2=A0 =C2=A0 229=20 229 =C2=A0 =C2=A0 229 =C2=A0 =C2=A0 229 =C2=A0 =C2=A0 229=20 D2=3D=20 1 =C2=A0 =C2=A0 =C2=A0=C2=A0 200 =C2=A0 =C2=A0 =C2=A0 3 =C2=A0 =C2=A0 =C2= =A00=20 80 =C2=A0 =C2=A0 =C2=A02 =C2=A0 =C2=A0 =C2=A0 =C2=A0=C2=A0 30 =C2=A0 =C2=A0= 50=20 100 =C2=A0=C2=A0 50 =C2=A0 =C2=A0=C2=A0 =C2=A0 200=C2=A0=C2=A0 90=20 0 =C2=A0 =C2=A0 =C2=A0=C2=A0 2 =C2=A0 =C2=A0=C2=A0 =C2=A0 =C2=A0 70 =C2=A0 = =C2=A0 1=20 we have to be able to find percentage of similarity of these blocks.=20 in this example -=20 the result has to be=C2=A0 something like these:=20 1- similarity(A1, A2) =C2=A0 -----> 99.99%=20 2- similarity(A1, D1) =C2=A0 -----> =C2=A080%=20 3- similarity( A1,D2) --------> 10%=20 Best Regards Mohammad Akbarpour Sekeh Student of PhD in Computer Forensic -IFD area Faculty of Computer Science and Information system University Technology Malaysia 81310 UTM Skudai, Johor, Malaysia Cell-Phone:+ 60-127890645=20 ________________________________ From: mehrnaz fani <fani.mehrnaz@ gmail.com> To: mohammad <moh_akb_s@yahoo. com> Cc: imagedsp@yahoogroup s.com Sent: Fri, 8 January, 2010 14:12:51 Subject: Re: [imagedsp] How to detection similarity of two Image Hello mr. mohammad for similarity evaluation you can calculate the corrolation coeficient of two images using this command: corr2(f1,f2) this will give you anumber=C2=A0in the interval of=C2=A0[0 1] 1 shows full similarity and 0 shows no similarity. you also=C2=A0can comper the histogram of images=20 or simply=C2=A0the=C2=A0squar error between to images as : Error=3Dsum(sum( (f1-f2).^ 2)) =20=20=20=20=20=20 ___________________________________________________________________
Hi
For measuring similarity of two image you have to use image siedility metrics
such as MSE,PSNR,SSIM,NC,...
Regards
dear all members
>I am trying to find rate of difference or rate of similarity of two
>Images.
>anyone can give me any Idea ?
>for example :
>if we have 2 Image : im1.jpg and im2.jpg
>----------------------------------
>f1=imread('im1.jpg');
>f2=imread('im2.jpg');
>F1=fft2(f1);
>F2=ff2(f2);
>similarity(f1,f2)=?
>-------------------------------
>How can I compare this two Fouriers?
>How can I find rate of similarity of this two image?
>the expected results are something like this:
>similarity(f1,f2)=99.9
>similarity(f1,f3)=98.7
>similarity(f1,f4)=34.5
>....
>Thanks
______________________________> try this paper and find more in its reference section. > http://www.cs.uwa.edu.au/~gian/docs/hons_paper.pdf Here is updated URL: http://www.csse.uwa.edu.au/~pk/studentprojects/gian/hons_paper.pdf Best regards, Mateusz Loskot______________________________