| 摘要 |
PURPOSE:To suppress a moire phenomenon and to obtain a variable magnification for image which is easy to recognize visually by correcting output image data obtained by an image power variation part by using a rounding error quantity. CONSTITUTION:Respective coordinate data of output image data obtained by an image magnification varying means 11 are approximated to image having a specific number of gradations and the error quantity of this approximation is held in an error quantity storage means 15. For example, next coordinate point data is corrected according to the error quantity of last held coordinate point data and then approximated to image data having a specific number of gradations. Consequently, the mean gradation of an approximated image outputted by a data approximating means 13 is extremely close to the mean gradation of the input image. Consequently, the approximation is prevented from being one-sided in one direction and image data which is approximated uniformly over the entire image is obtained; and the moire phenomenon which is caused by a power varying method based upon a simple rule can be suppressed and the variable power image which is easy to recognize visually is obtained. |
