Android Question Image comparison

[Smee]

I know this question has come up quite a few times in the past. Is there a way to compare images with a reasonably high degree of accuracy.
Cheers

 

[Erel]

You can compare two identical images and say whether they are identical or not. Comparing two similar images is much more complicated.

 

[Smee]

Thanks Erel
I was afraid of that. The images would probably never be identical but if i stored a few views of each image it might get me there.
Whicch library would be the best to use?
Cheers

 

[Erel]

You can compare the raw bytes in order to test whether two image files are identical.

 

[vbmundo]

I don't imagine an Algoritm that do that

an image can be affected by differences in light of the time, including taking the picture from the exact same place as the first, by comparing pixel by pixel values could give differences.

There are currently Alarm applications that forces you to take a picture of an object (that has previously photographed) and finding the coincidence, your alarm stops ringing. it forces you to wake up., but I honestly do not understand how they succeed.

 

[lemonisdead]

honestly do not understand how they succeed

Some ideas there (but I was quickly lost while trying to apply. Good luck)

 

[inakigarm]

Maybe if you can explain better what are you looking for (faces, places, etc..) people can point you in right direction (ex: opencv, java code, external utils like https://www.raymond.cc/blog/how-to-compare-the-difference-between-two-identical-looking-images/)

 

[svenjamin]

I have no idea how well this would work, but I could imagine that a cross correlation between the two pictures (probably in grayscale) could deliver a kind of merit for similarity. But then again, I have no idea how well this works .

 

[Smee]

Thanks for the replies people,
I am trying to identify images of objects or a cross section of an object. I understand that i would probably need a library which is capable of keypoint identification. When i have read up on this stuff it seems a lot of the use is for facial and scenery recognition. What i would probably have to do is store several images of the same item and any comparison shots would probably have to be done in grayscale. There are possibilities out there but some of those would need to be wrapped to a library I would assume. (a paid project maybe?)

Thanks again for the replies, i will keep looking and checking back on this thread regularly

 

[Smee]

Maybe if you can explain better what are you looking for (faces, places, etc..) people can point you in right direction (ex: opencv, java code, external utils like https://www.raymond.cc/blog/how-to-compare-the-difference-between-two-identical-looking-images/)

Thanks for this link, i had not seen this, i will check it out