Methods, systems, and programming for computer display of images, text, and/or digital content

• US 20030095135A1
• Filed: 05/02/2002
• Published: 05/22/2003
• Est. Priority Date: 05/02/2001
• Status: Active Grant

• Current Assignee: Marlborough Software Development Holdings Inc. (Pageflex, Inc.)
• Original Assignee: John S. Collins, Michael R. Dewsnap, Robert J. Eggers, Sampo J. Kaasila
• Inventors: Dewsnap, Michael R., Eggers, Robert J., Collins, John S., Kaasila, Sampo J.
• Granted Patent: US 7,222,306 B2
• Time in Patent Office: Days
• US Class Current: 345/613
• CPC Class Codes: G06F 16/9577 Optimising the visualization of content, e.g. distillation of HTML documents
• CPC Class Codes: G06F 3/0481 based on specific properties of the displayed interaction object or a metaphor-based environment, e.g. interaction with desktop elements like windows or icons, or assisted by a cursor's changing behaviour or appearance
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures
• CPC Class Codes: G06F 3/14 Digital output to display device ; Cooperation and interconnection of the display device with other functional units
• CPC Class Codes: G06T 11/203 Drawing of straight lines or curves
• CPC Class Codes: G06T 11/40 Filling a planar surface by adding surface attributes, e.g. colour or texture
• CPC Class Codes: G06T 2200/12 involving antialiasing
• CPC Class Codes: G09G 2320/0606 Manual adjustment
• CPC Class Codes: G09G 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• CPC Class Codes: G09G 2340/0414 Vertical resolution change
• CPC Class Codes: G09G 2340/0421 Horizontal resolution change
• CPC Class Codes: G09G 2340/045 Zooming at least part of an image, i.e. enlarging it or shrinking it
• CPC Class Codes: G09G 2340/0457 Improvement of perceived resolution by subpixel rendering
• CPC Class Codes: G09G 2340/0492 Change of orientation of the displayed image, e.g. upside-down, mirrored
• CPC Class Codes: G09G 2340/145 related to small screens
• CPC Class Codes: G09G 2370/027 Arrangements and methods specific for the display of internet documents
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/00 Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators image data processing or generation, in general G06T
• CPC Class Codes: G09G 5/026 Control of mixing and/or overlay of colours in general G09G5/022 and G09G5/024 take precedence
• CPC Class Codes: G09G 5/24 Generation of individual character patterns
• CPC Class Codes: G09G 5/28 : for enhancement of character form, e.g. smoothing
• CPC Class Codes: G09G 5/34 : for rolling or scrolling
• CPC Class Codes: G09G 5/42 : characterised by the display of patterns using a display memory without fixed position correspondence between the display memory contents and the display position on the screen
• CPC Class Codes: H04M 1/72445 : for supporting Internet browser applications

Abstract

A bitmap of a shape, such as a font, can be subpixel optimized by producing for each of a display'"'"'s subpixels a coverage value representing the percent of its area covered by the shape being represented and by distributing, to prevent color imbalance, an amount of a given subpixel'"'"'s coverage value to nearby subpixels of different colors as a function of the percent of the given subpixel'"'"'s coverage value that causes color imbalance. Web pages can be displayed with scaled-down and subpixel optimized images. A given layout of a Web page can be displayed at each of at least two different selected scale factors, with the font bitmaps used to represent characters in the display at each scale factor having their shape and pixel alignment selected to improve readability for the particular pixel size at which they are displayed at each such scale factor.

Claims

1. A method of producing a subpixel-optimized bitmap of a shape suitable for display on a subpixel addressable screen having pixels comprised of separately-addressable, differently-colored subpixels, said method comprising:

associating a luminosity value with each subpixel of the bitmap by;

rasterizing the shape being represented to produce for each given subpixel a coverage value for the area in the bitmap corresponding to subpixel'"'"'s location, which coverage value represents the percent of the given subpixel'"'"'s area in the bitmap that is covered by the shape being represented;

performing a color balancing function for said plurality of subpixels, which color balancing distributes portions of the coverage values produced for individual subpixels by said rasterization to nearby subpixels of different colors to prevent color imbalance; and

associating a luminosity value with each subpixel represented in said bitmap based on the coverage value produced for each given subpixel by said raterization, as decreased by any of said color balancing distributions from said given subpixel'"'"'s coverage value to other subpixel coverage values and as increased by any of said color balancing distributions to the given subpixel'"'"'s coverage value from other subpixel coverage values;

wherein the percent, if any, of a given subpixel'"'"'s coverage value that is distributed by said color balancing varies as a function of the percent of said coverage value that causes color imbalance.

2. A method of displaying—

on a subpixel addressable screen having pixels comprised of separately-addressable, differently-colored subpixels—

digital content including text and/or images represented by a mark-up language including tags that dictate the format in which such content is to be displayed and tags that identify images to be displayed as part of said content, said method comprising;

accessing said digital content, including accessing one or more images, from a device in which said content is stored or is generated dynamically;

performing a down-scaling and subpixed-optimization process in which;

each of said accessed images is a source image for the process;

said process produces from each such source image a corresponding scaled-down, subpixel optimized image;

each such scaled image represents the source image from which it has been produced at a lower pixel resolution than the pixel resolution of said source image;

each such scaled image also represents said source image in a subpixel-optimized manner by causing the luminosity associated with each subpixel within a given pixel of the scaled image to represent the luminosity of the subpixel'"'"'s color in a portion of the source image that differs for each subpixel as a function of the subpixel'"'"'s different position in the given pixel; and

displaying said accessed digital content on said subpixel-addressable screen in a format determined at least in part by one or more tag in said content, including, as part of said formatted display, displaying said scaled images in a subpixel-optimized manner on said screen.

3. A method of displaying a web page comprising:

accessing a web page'"'"'s content including one or more images and one or more strings of displayable text;

laying out the web page in a layout space having a horizontal and a vertical layout resolution, so as to determine a layout position for each of said images and each displayable character of said strings in said layout space, including;

treating said images and said displayable characters as having respective layout sizes in said layout space;

flowing displayable characters of said strings of across line boundaries, based on the layout size of said displayable characters, by breaking portions of strings that cross a line boundary into separate single line strings, each of which fits on a single line in said layout space; and

displaying at least a portion of said laid out web page on a display screen at a selected scale factor, including;

displaying both said images and single line character strings at locations in said display corresponding to the positions at which they have been laid out in said layout space, scaled as a function of said selected scale factor;

representing each of said images in said display by a corresponding bitmap in said display that has a pixel size relative to the image'"'"'s layout size determined as a function of said selected scale factor; and

representing a given single line strings by an image composed from a plurality of separate font bitmaps representing the characters in said string, where the image of an individual character of said string has a pixel size relative to the character'"'"'s layout size determined as a function of said selected scale factor;

wherein;

said display of a given portion of said laid out web page is performed at each of at least two different selected scale factors; and

the shape and pixel alignment of a character represented by one of said font bitmap at a given scale factor has been selected to improve readability as a function of the size of said font bitmap used to represent the character at the given scale factor, causing a given character in a given string in two displays of a given portion of said web page layout performed at different selected scale factors to be displayed with font bitmaps of different pixel size that represent the given character with different shapes and pixel alignments.