Abstract: An electrophotographic image forming apparatus and a halftoning correction method thereof are provided. The electrophotographic image forming apparatus according to the example embodiments of the present invention, comprises a storage unit storing a plurality of dot patterns representing print characteristics of a print engine, a data area dividing unit dividing halftoned print data into data areas respectively having the same size as the dot patterns, a pattern extraction unit extracting an appropriate dot pattern with respect to each of the divided data areas by comparing dots in the data areas to the dot patterns, and a pattern converter changing the data area to the extracted dot pattern. Therefore, an optimal halftoned image can be provided.

Abstract: An image processing method and apparatus using the same. The method includes converting a continuous-tone color image into a plurality of intermediate images corresponding to a plurality of colors, dividing a first intermediate image among the plurality of intermediate images into a plurality of first screen cells of which a size and a shape are uniform in correspondence with a plurality of unit print areas, and performing half-toning on a first intermediate image, and dividing a second intermediate image among the plurality of intermediate images into a plurality of second screen cells of which the size and the shape are non-uniform and are not in correspondence with the plurality of the unit print areas, and performing the half-toning on the second intermediate image. Thus, printing can be performed at a fast speed with optimal picture quality.

Abstract: A screen designing method and a screen designing device for reducing a moire pattern are provided. In the screen designing method, screen parameters corresponding to a preset screen frequency, a preset screen angle, and a preset resolution are detected first. Then, the coordinates of dot centers being the centers of cluster dots each with a plurality of microdots are detected. Next, a dot center order indicating a sequence in which the dot centers are turned on is determined. Thereafter, a microdot order indicating a sequence in which the microdots are turned on is determined using an evaluation function that quantitates the perception of a moiré pattern by a human's vision. Accordingly, the microdot order is determined using the evaluation function based on the visual characteristics of a human, thereby preventing patterns that degrade the quality of image formation and a moiré pattern from being generated.

Abstract: A method and apparatus to form an image by half-toning a plurality of areas of an input image using different multi-tone patterns with reference to edge information regarding edge areas and flat areas detected from the input image. The method includes detecting edge areas and flat areas of an input image, half-toning the input image by applying different multi-tone patterns to the detected edge and flat areas, and generating a half-toned image for the input image by integrating the edge and flat areas that have been half-toned with the different multi-tone patterns.

Abstract: A system and a method for forming an image are provided. The method includes the steps of dividing an input image into sub cells including a predetermined number of pixels, calculating gray level values of the sub cells, calculating direction information values of the sub cells;, selecting halftone patterns corresponding to the gray level values and the direction information values from a stored lookup table, and applying the halftone patterns to positions of the sub cells so as to generate and output a binary image for the input image.

Abstract: An image forming apparatus capable of setting optimal print options for test prints of a primitive image and a method thereof. The image forming apparatus includes an image data processing part to create a plurality of test images by converting a primitive image according to a plurality of predetermined sets of print options, an image print part to print the plurality of test images created by the image processing part, a key input part to select one of the plurality of the printed test images, and a control part to set the print options of the selected test image using the key input part print options of the primitive image. Accordingly, the user need not separately set print options for more than one test print performed by more than one print job, since the optimal print options of the primitive image are set by comparing and selecting the test images pre-printed according to the different sets of print options.