From ITA puzzles.

A rebus is a phrase or sentence expressed all or in part through pictures. For this puzzle, you will use pictures from this archive (use the included file "images.txt" to map pictures to the associated words). Write a program that will take an English sentence (here’s a list of test cases for you to use) and generate a rebus from it. Here’s a simple example:

(:dove + sl - d) (:tie + hs - e) (:book + wr - bo) (:bee + hr - b)
                      solve this work here

That is, each word becomes a parenthesized expression with up to three components: a word corresponding to a picture from the clipart library, a sequence of letters to be added to the name of the picture, and a sequence of letters to be deleted from the name. Distinguish words used as pictures from other sequences of letters by prepending a colon. The order of letters must match: the letters to be added must be in the order in which they would appear in the target word, and the letters to be deleted must be in the order in which they appear in the image name. Your program should produce plain text output.

But there’s more to the puzzle than that. Suppose we charge 5 points for every consonant you add or delete, and 1 point for every vowel. Now come up with a rebus that costs the fewest points. The example above costs 57 points, but this rebus of the same phrase:

(:love + so - o) (:house + ti - oue) (:rake + wo - ae) (:ear + he - a)
                      solve this work here

Finally, you can reduce the cost even further by adding or subtracting images (which cost nothing) instead of letters. If you use recursive encodings, you can get rid of letters altogether. For instance, a recursive rebus for “solve” is:

          (:dove + (:castle - :cat) - (:badge - :bag))
                             solve

Write a program to generate recursive rebuses like the one above. Your program may use a mix of letters and pictures; balance performance against optimal scores as you see fit. Even for all-picture rebuses, a shorter rebus is better.