Methods, computer program products and apparatuses are disclosed for processing images to detect and/or remove halftone. In one aspect, a portion of an image comprising a plurality of color channels is selected for processing (210), a frequency domain representation of the selected portion is generated for each color channel (220), data relating to predetermined regions in the frequency domain representations is processed (230), and halftone present in the selected portion is detected based on a result of the processing the data (240). In another aspect, an image is arranged into a plurality of bands each comprising a predetermined number of consecutive lines of pixels, each of the plurality of bands is arranged into a plurality of tiles of pixels, one of the plurality of tiles is selected as a selected portion, data relating to the selected portion is processed and halftone present in the selected portion is detected based on a result of the processing and on a result of processing at least one other portion of the image. Halftone may be detected based on spatial characteristics or frequency characteristics within the selected portion and detected halftone may be removed from spatial domain data or frequency domain data relating to the selected portion.

 
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< System for certifying whether printed material corresponds to original

> Image formation with priority selection of correction table based on match with print sheet setting information

> Image forming apparatus and method for controlling the same

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