Image quality improving apparatus and method using detected edges

An image quality improving method, comprising the operations of:

• estimating edge pixels of a text area in a predetermined detection area, using at least one processing device, to be edge-detected from an input picture data containing a text and an image;
• judging actual edge pixels based upon a number of edge-estimated pixels in a multiple window area and saturation values of individual edge-estimated pixels;
• and
• emphasizing individual actual edge pixels with different edge emphasis coefficients according to saturation values of the actual edge pixels
• wherein the edge pixel estimating operation comprises:
• measuring lightness variation from individual pixels in the predetermined detection area to be edge-detected;
• and
• calculating binary data of the individual pixels according from multiple windows collectively, the binary data being composed according to different sampling procedures composing the multiple windows from an area having lightness variation, and judging connectedness and similarity of the calculated binary data according to the individual windows, to estimate whether a given pixel is an edge.

An image quality improving method, comprising:

• estimating whether pixels within a detection area of an input picture are edges, using at least one processing device, and using lightness variations of the pixels, to identify corresponding edge-estimated pixels;
• judging whether the edge-estimated pixels are edges using pixel saturation values and a number of edge-estimated pixels;
• and
• applying a plurality of edge emphasis coefficients to edge-judged pixels in accordance with respective saturation values of the edge-judged pixels,
• wherein the estimating whether the pixels within the detection area of the input picture are edges using lightness variations of the pixels comprises:
• for each pixel having a lightness value variation exceeding a predetermined reference lightness variation value, comparing respective lightness differences of surrounding pixels to calculate binary data representing a given pixel with varied lightness and the surrounding pixels;
• using the binary data, calculating a binary data connected component for each of multiple windows collectively, the multiple windows representing surrounding pixel sample sizes, and being centered on the given pixel with varied lightness;
• determining whether the multiple windows have a connectedness using the respective binary data connected components;
• for windows determined to have connectedness, determining whether the windows have similarity;
• and
• for windows determined to have similarity, estimating the given pixel with varied lightness to be an edge.

An image quality improving apparatus, comprising:

• an edge sorting section estimating whether pixels within a detection area of an input picture are edges using lightness variations of the pixels, to identify corresponding edge-estimated pixels;
• an edge detecting section judging whether the edge-estimated pixels are edges using pixel saturation values and a number of edge-estimated pixels;
• and
• an edge emphasizing section applying a plurality of edge emphasis coefficients to edge-judged pixels in accordance with respective saturation values of the edge-judged pixels,
• wherein the edge sorting section comprises:
• a lightness variation measuring section determining whether lightness value variations of pixels within the detection area exceed a predetermined reference lightness variation value;
• and
• a halftone image detecting section
• comparing respective lightness differences of surrounding pixels, for each pixel having a lightness value variation exceeding the predetermined reference lightness variation value, to calculate binary data representing a given pixel with varied lightness and the surrounding pixels,
• using the binary data, calculating a binary data connected component for each of multiple windows collectively, the multiple windows representing surrounding pixel sample sizes and being centered on the given pixel with varied lightness,
• determining whether the multiple windows have a connectedness using the respective binary data connected components,
• for windows determined to have connectedness, determining whether the windows have similarity, and
• for windows determined to have similarity, estimating the given pixel with varied lightness to be an edge.