| 摘要 |
An apparatus for processing an image into binary data is selectively operable with a fixed threshold level and a variable dither threshold level. When a threshold level commmand signal specifies the dither threshold level, a switchover means detects image data read from a character or like black-white image portion on an original document and specific part of a halftone image portion which is approximate in density level to black. The detection output forcibly changes the threshold level command signal from a dither threshold level command to a fixed threshold level command. The dither processing, therefore, occurs only for a minimum necessary halftone image portion in accordance with an image condition on the document.
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