1. A computer-implemented method, comprising: obtaining, by a data processing device, initial quality scores for relevant images for a query, the relevant images being images previously selected to be referenced by search results for the query; selecting, by a data processing device, a query-specific transformation factor for the query the transformation factor representing a measure of importance of image quality for computing relevance scores of relevant images for the query, the transformation factor being selected based, at least in part, on a comparison of a first number of previous user selections of high quality images for the query to a second number of previous user selections of high quality images for one or more other queries, a high quality image being an image having an initial quality score that meets a threshold score; computing query specific quality scores for the relevant images based on a function of the transformation factor for the query and the initial quality scores for the images; and computing adjusted relevance scores for the relevant images based on the query specific quality scores and initial relevance scores for the relevant images.