Algorithm for finding similar images

by

I have done something similar, by decomposing images into signatures using wavelet transform.

My approach was to pick the most significant n coefficients from each transformed channel, and recording their location. This was done by sorting the list of (power,location) tuples according to abs(power). Similar images will share similarities in that they will have significant coefficients in the same places.

I found it was best to transform in the image into YUV format, which effectively allows you weight similarity in shape (Y channel) and colour (UV channels).

You can in find my implementation of the above in mactorii, which unfortunately I haven’t been working on as much as I should have 🙂

Another method, which some friends of mine have used with surprisingly good results, is to simply resize your image down to say, a 4×4 pixel and store that as your signature. How similar 2 images are can be scored by say, computing the Manhattan distance between the 2 images, using corresponding pixels. I don’t have the details of how they performed the resizing, so you may have to play with the various algorithms available for that task to find one which is suitable.

More Related Contents:

  1. The number prodigy : reverse sum of pattern
  2. Sum a number with divisors to get another number
  3. Unique (non-repeating) random numbers in O(1)?
  4. Circle line-segment collision detection algorithm?
  5. How to create the most compact mapping n → isprime(n) up to a limit N?
  6. How do I calculate a point on a circle’s circumference?
  7. Fast permutation -> number -> permutation mapping algorithms
  8. Algorithm to detect intersection of two rectangles?
  9. What distribution do you get from this broken random shuffle?
  10. Sort points in clockwise order?
  11. How do you calculate the average of a set of circular data? [closed]
  12. How do Trigonometric functions work? [closed]
  13. Precise subpixel line drawing algorithm (rasterization algorithm)
  14. Mapping N-dimensional value to a point on Hilbert curve
  15. What’s a good algorithm to determine if an input is a perfect square? [duplicate]
  16. Puzzle: Find largest rectangle (maximal rectangle problem)
  17. náµ—Ê° ugly number
  18. How can I calculate the age of a person in year, month, days?
  19. Calculate largest inscribed rectangle in a rotated rectangle
  20. 3D Least Squares Plane
  21. Two Rectangles intersection
  22. Fastest primality test
  23. Shortest distance between points algorithm
  24. The Sieve of Atkin
  25. Efficient maths algorithm to calculate intersections
  26. Test if a number is fibonacci
  27. An inverse Fibonacci algorithm?
  28. what is the fastest way to find the gcd of n numbers?
  29. “Rounding” colour values to the nearest of a small set of colours
  30. How can I perform Collision Detection on rotated rectangles? [closed]

Leave a Comment