SOS,Find a good way to compare two id pictures to decide whether they are the same person.
Posted on 2001-07-18
hi,dear experts,here I need your kind help very much.
Firstly,I will introduce to you the backgroud of my project.I have to compare two id card pictures to see if they are the same person or not.The first picture is the previous one which has been stored in the database,now I have his(or her)another picture recently photographed,suppose there sizes are the same(If not,I can use the function 'copyrect' to make the current one be enlarged or minimized to fit the database one.)
Secondly,I'd like to tell you my methods used in the project.first,I partition them into '9rows*6lines' blocks(so there are 54 blocks,difference[i] stands for the diference of each block),then I will compare each pixel(red,green,blue) to see if they are the same,if not, inc(difference[i]) until we finish them.Now I will give every block's coefficient[i](between 0 and 1) according to their importance in the comparing process,for example,the section which the eyes are located,I will give 0.9 to it.Now the Difference:=sum(difference[i]*coefficient[i]),right?Second,I will figure out the all pixels,the pixels*3 is the counts I have compared in sum,so:
Third,I will give a threshold,if similarextent is larger than the threshold,I will assume they are the same one.
Thirdly,I will give you the reasons that tell the method's incompleteness:
1.The two pictures may be not both colorful or black and white;
2.The pictures may has been reprocessed,such as smoothed,sharpened,inverted,luminance intensified or weakened,diffused,mosaiced.
So the method of comparing the red,green and blue of each pixels is not incomplete,right?Do you have any better methods?I don't want to get an exact and very precise method but a realizable one.Please help me,Thank you very much.(If answered,I will give more points:))