1. A method of indexing on a digital image which has been compressed or is to be compressed according to a compression method using compression parameters which influence the resulting quantity of information contained in at least part of the compressed image, the indexing requiring a predetermined quantity of information, characterised in that the method comprises, prior to a step of indexing the digital image, the steps of: determining at least one of the compression parameters for at least part of the compressed image, checking whether the resulting quantity of information corresponding to the compression parameters is adapted to the predetermined quantity of information required for the indexing of the image.