Digital copying machine that automasks data for small originals if a document feeder is present

Images of certain features of the copier itself (indicia, markings, operational components) are searched for, in a defined field of view used for copying. Any such images found, because they are not covered by a document being copied, are suppressed. This avoids the objectionable appearance of machine features from copies on full-size sheets of print medium, and deposition of ink on mechanisms of the copier itself. Preferably things in the field of view are imaged, and the image is parsed for the certain features-readily done by a software or firmware module or ASIC stage, easily incorporated into already-existing software, firmware or circuitry at minor unit cost. Preferably the copier features include document-size indicia, to aid determination by the copier whether a standard-size document is being copied, and thus whether suppression is in order. The search could be for operational machine features rather than special indicia, but those features may not be ideally positioned. Suppression may be of all machine features if the "certain" features are found. Preferably copying of shadows at edges of a document is also suppressed-an easy function to add to the primary operation described. In finding of document edges, it is desirable to ignore all machine features. Preferably photosensors acquire image data from a document, and a print stage prints an image using the data. A feeder, if in operation, positions a document at the sensors. If the feeder is attached to the copier but not in service, data are analyzed automatically to find whether the document is below a particular standard size; and, if so, in response printing of data portions is suppressed automatically.