Patent ID: 7016078

Claim:
An image-forming apparatus, which conducts a quasi-halftone processing in respect to image signals, comprising: an inputting section to input said image signals; and a converting section to apply a gradation-converting processing to said image signals inputted by said inputting section, on the basis of a predetermined gradation-converting curve, to generate converted image signals; wherein said predetermined gradation-converting curve includes at least one of: a first gradation characteristic in which a maximum absolute value of a difference between a lightness gradation curve obtained on the basis of lightness and/or density varying image signals generated by said image-forming apparatus and its smoothed curve in a range of about 1/10 of its gradation number is not greater than 1; a second gradation characteristic in which a maximum absolute-value of first order differential values of a difference curve between a lightness gradation curve obtained on the basis of lightness and/or density varying image signals generated by said image-forming apparatus and its smoothed curve in a range of about 1/10 of its gradation number is not greater than 100; and a third gradation characteristic in which a maximum absolute-value of first order differential values of a difference curve between a first smoothed curve in a range of about 1/100 of a gradation number and a second smoothed curve in a range of about 1/10 of a gradation number, both of which are generated on the basis of a lightness gradation curve obtained on the basis of lightness and/or density varying image signals formed by said image-forming apparatus, is not greater than 100.