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AssigneeOMRON Corporation
InventorsShinya Sonoda, Atsushi Noda, Hiroki Tabata, Masashi Sugimoto, Junji Hiraishi
Estimating the term…
An image input device photoelectrically reads a document and outputs digital data. This image reader includes a first voltage generating circuit for generating a first voltage for setting an upper limit of contrast, a second voltage generating circuit for generating a second voltage for setting a lower limit of contrast, and an A/D converter for converting an input analog signal to a digital signal in accordance with the first and second voltages. At least one of the voltages generated by the first voltage generating circuit and second voltage generating circuit is variable. Also disclosed is an image reader including a dark voltage memory circuit, storing dark voltages corresponding to color signals R, G and B, a first switching circuit sequentially switching the output of the dark voltage memory circuit and outputting a selected dark voltage, a second switching circuit adapted to synchronously output a selected color signal corresponding to the selected dark voltage, and a differential amplifier subtracting the selected dark voltage from said selected color signal.
An image reader for reading a picture signal in analog form and outputting said picture signal in digital form, comprising:
A method of improving color contrast in a picture signal, comprising the steps of:
A method of reading an image, the method comprising the steps of:
A method of adjusting the contrast of an image signal, the method comprising converting said image signal to a digital signal referenced to a high voltage reference and a low voltage reference and adjusting contrast by varying the differences between said high voltage reference and said low voltage reference.
An apparatus for adjusting the contrast of a signal read from an image, comprising:
Dependencies are inferred from the claim text.