1. A method for matching test imagery to reference imagery, comprising the acts: generating color histogram data that corresponds to test imagery captured by a camera-equipped mobile device; matching said test imagery color histogram data with color histogram data that corresponds to reference imagery, said matching being performed by a hardware processor of said camera-equipped mobile device; said test imagery histogram data and said reference imagery histogram data comprising values corresponding to a plurality of quantized bins; and said matching including determining one or more of the following: a. a number of occupied bins in the test and reference imagery histograms; b. a number of occupied bins common to both the test imagery and reference imagery histograms; c. a number of occupied bins combined between both the test imagery and reference imagery histograms; d. a number of pixels common to both the test imagery and reference imagery histograms (histogram intersection); e. a percentage of occupied bins of the test imagery histogram that are occupied in the reference imagery histogram; f. a ratio of said histogram intersection to number of occupied bins of the test imagery histogram; g. nonzero bins of test imagery histogram; h. nonzero bins of reference imagery histogram; i. nonzero bins of test imagery histogram that are a subset of nonzero bins of reference imagery histogram; j. a number of nonzero bins of test imagery histogram that are a subset of nonzero bins of reference imagery histogram; k. nonzero bins of reference imagery histogram that are a subset of nonzero bins of test imagery histogram; and l. a number of nonzero bins of reference imagery histogram that are a subset of nonzero bins of test imagery histogram.