A desired character mainly composed of standard width dots selected from a matrix of orthogonally disposed rows and columns is displayed on a screen during scanning of the screen in horizontal and vertical directions. The display is smoothed by a circuit responsive to data stored in a memory. The smoothing involves the selected addition or removal, to or from particular portions of the character, of a small dot having a width one-third of the standard dot width.
An improved method of displaying a character on a raster device using a modified center point fill method is described, beginning by defining the character by an outline of a series of edges in a path, scaling the character to a pixel grid of columns and scan lines in display space, identifying as a cross each point where an edge of the character intersects a horizontal midline of a scan line and storing a list of the crosses pairwise along each scan line as cross pairs. For each one of the cross pairs, all pixels having centers that are located between the crosses of the cross pair are selected and the range of the selected pixels is stored as a run for the cross pair. For each cross pair between two adjacent pixel centers, the pixel containing the horizontal midpoint of the cross pair is stored as a run for the cross pair. Adjacent cross pairs are identified and the run for each cross pair is tested against the run displaying each adjacent cross pair to see if the runs are properly connected. If they are not then at least one pixel is selected and an existing run is extended to include the selected pixel, if possible. Otherwise, a pseudocross pair is created as needed to properly connect the runs. Narrow horizontal features are also identified and connected to the character using similar methods.
An image forming apparatus comprising: a laser beam irradiating device for irradiating a laser beam onto a record support member; a storage device for storing image data composed of a plurality of dots; a detection device which reads out the image data from the storage device so as to detect whether or not dots to be subjected to light emission by the laser beam are arranged continuously; and a control device for controlling an irradiation period of the laser beam irradiating device to a smaller value when the detection device has detected that the dots to be subjected to light emission are arranged continuously.
Display data is read out from a display memory (2) and the display data thus read out is written in the buffer memory (8). Then, in a time sharing manner relative to the writing, the display data is read out from the buffer memory (8), and a smoothing processing is carried out on the basis of the display data thus read out and the display data read out from the display memory (2).
A special slanted line pattern is detected using pattern data of eight picture elements S0-S3, S5-S8 which surround a current display picture element S4. A half-picture element pattern provided on the current display picture element S4 and having a specified positional relationship to the detected pattern is added to this detected pattern, is deleted from the detected pattern, or is added to the detected pattern and given the same color as the detected pattern.
A graphic display control method and apparatus wherein illumination of pixels on a display screen of an interlace type CRT in a first field and a second field is controlled so that each point on a line is displayed on the display screen of the interlace type CRT by a combined illumination of a pixel in the first field and the second field or a combined illumination of one of two vertically adjacent pixels in the first field or the second field and the second pixel in the second field or the first field. The smooth line is displayed by a series of points.
