Abstract: A method and a device for detecting copies or near-copies of images, comprises receiving an initial image, converting the initial image to grayscale, resizing the grayed image to a reduced image having a plurality of rows and an even number of columns, computing an overall signature for the reduced image, and determining whether the initial image is a copy or near-copy of an image according to the result of a comparison between the overall signature of the reduced image and reference image signatures. The step of computing the overall signature comprises the steps of computing a row signature for each row of the reduced image, the computation being based on a comparison of values obtained statistically across subsets of symmetrical pixels in each row, and concatenating the row signatures in order to obtain an overall signature.

Abstract: A method for searching for images similar to a query image in a collection of images, using a representation of the query image in a form of a vector of characteristics allocating a weight to each of the characteristics, and including querying an inverted index matching each of the characteristics with images from the collection. The querying the inverted index includes integrating, into a list, one or more images from the collection that are matched in the inverted index with a first characteristic selected depending on the weight allocated to same in the vector representing the query image. The integrating into the list is repeated for another characteristic selected depending on the weight allocated to same in the vector representing the query image until the number of images of the collection integrated into the list reaches a target number.

Abstract: A method and a device for detecting copies or near-copies of images, comprises receiving an initial image, converting the initial image to grayscale, resizing the grayed image to a reduced image having a plurality of rows and an even number of columns, computing an overall signature for the reduced image, and determining whether the initial image is a copy or near-copy of an image according to the result of a comparison between the overall signature of the reduced image and reference image signatures. The step of computing the overall signature comprises the steps of computing a row signature for each row of the reduced image, the computation being based on a comparison of values obtained statistically across subsets of symmetrical pixels in each row, and concatenating the row signatures in order to obtain an overall signature.