An area filling device includes an edge table memory for storing an edge table having data related to the edges, and an address table memory for storing edge table address data for every Y coordinate value. An operation circuit calculates data related to edges consisting of a closed loop figure. An active-edge table circuit forms first, second and third active-edge tables for every Y coordinate value from the data related to the edges stored in the edge table storing memory. The first and second active-edge tables indicate bit data having predetermined bits at X coordinate positions where there are an edge which is not a horizontal edge, and endpoints of a horizontal edge, respectively. The third active-edge table indicates bit data having a predetermined bit at an X coordinate position where there is an endpoint of an edge. A logic circuit inverts the predetermined bits defined in the first and second active-edge tables. An OR gate calculates an OR operation on the bit data from the logic circuit and the bit data related to the third active-edge table and supplied from the active-edge table circuit. The operation results serve as print data.

A display control device comprises a work memory including at least a plurality of memory bits each for storing one-bit data indicating whether or not each pixel is inside a figure of plane geometry having a contour such as a polygon, a control unit for scanning each of a plurality of raster scan lines and searching for at least one pixel which can be assumed to form a line segment which partially constructs the contour of the figure so as to generate a control signal for controlling bit inversion to determine the inside of the figure, a selecting unit for receiving the one-bit data of each pixel which is sequentially delivered by the work memory and inverting the one-bit data so as to select one from among the original one-bit data and the inverted one-bit data according to the control signal from the control unit, and output the selected data; a unit for writing the selected data from the selecting unit into a corresponding one of the plural memory bits of the work memory.

Segment data expressing segments which form the contour of a graphic figure are provided. Connection mode data expressing the connection modes between the segments are generated. The loops included in the graphic figure are detected on the basis of the segment data and the connection mode data. Even if the segments imperfectly define the contour, the loops can be detected through the step of correcting the segment data and the connection mode data.

Apparatus for preparing image reproduction data from original image data which define visible representations to be reproduced, including a memory for storing original image data defining a plurality of visible representations each of which has at least one enclosed solid-imaging area to be solid-imaged, a first data preparing device for preparing solid-imaging data representative of the at least one solid-imaging area of a first kind of the visible representations, by effecting determination on the number of a winding count for the first kind of visible representations, based on the original image data, a second data preparing device for preparing solid-image data representative of the at least one solid-imaging area of a second kind of the visible representations, without effecting determination on the number of the winding count for the second kind of visible representations, based on the original image data, and a selector for selectively rendering operative one of the first and second data preparing means.

By an image processing method, a contour of a figure is represented with a series of clockwise outline vectors, a sense of each vector being set such that the figure be painted out by painting a left side of the vector, then, an outline is created from the outline vectors, and the figure is painted through a scanning operation in an x-axis direction by starting a painting operation at an odd-numbered intersection of the outline and a horizontal scanning line and suspending the painting operation at an even-numbered intersection thereof, thus painting pixels between the odd-numbered intersection and the even-numbered intersection, inclusive of the pixel at the odd-numbered intersection but exclusive of the pixel at the even-numbered intersection. In order to create the outline, plotting points for the outline are first calculating from the outline vectors through use of Bresenham algorithm. Then, a positional relation of a current plotting point to the previous one and the next one is obtained. A positional variation in the y-axis direction between the current plotting point and the previous one calculated based on the positional relation is stored in a flag. In creating the outline, outline components are plotted one after another based on the positional relation of the current plotting point to the previous one and to the next one, or based on the positional variation in the y-axis direction.