Other

Google Inc.

Raphael L Levien

David J Kuettel

Romain P Guy

Chet Haase

Brian Stell

A non-transitory computer-readable storage medium may comprise instructions stored thereon. The instructions, when executed by at least one processor, may be configured to cause the first computing system to at least generate a collection of inverse transformations of an index of the document, the collection of inverse transformations being based on at least one asymmetric local edit to the document by the first computing system, determine a location within the document to perform a remote edit by the second computing system based on the collection of inverse transformations of the index of the document, perform the remote edit to the document at the determined location based on the remote edit by the second computing system, and perform at least one local edit to the document based on the at least one asymmetric local edit to the document by the first computing system.

Maintaining state of document concurrently edited by two computing systems by determining locations of edits based on inverse transformations

A method for storing information may include determining whether a received data object fits inside a particular one of a plurality of free blocks in a memory bitmap. Each of the plurality of free blocks may include a column of the memory bitmap with a top margin, a bottom margin, and a predetermined width. If the received data object fits, the received data object may be stored in the particular one of the plurality of free blocks, starting at the margin of the particular one of the plurality of free blocks. The particular one of the plurality of data blocks may be resized by moving the margin to start below or next to the stored received data object. The determining may include, for each of the plurality of free blocks, a height of the received data object may be compared with a height of each of the free data blocks.

Fast, dynamic cache packing

A compressed font file including compressed data is received. The compressed data is decompressed to generate decompressed data. An attempt to validate the decompressed data is made. Within the decompressed data, a predetermined pattern of invalid data corresponding to an element of a font file is detected. The font file is reconstructed by replacing at least some of the invalid data with the element.

System and method of compressing data in font files

A computer-implemented method technique can intercept, at a server including one or more processors, a first request for a source document representing a web page, the first request being transmitted from a computing device to a web server. The first request can include web browser information indicating web browser software executing on the computing device. The technique can intercept the source document being transmitted from the web server to the computing device in response to the first request. The source document can specify one or more fonts in which to display text in the source document. The technique can generate the web page, determine unique characters displayed at the web page, and obtain one or more font subsets. The technique can then transmit information to the computing device based on whether the web browser software is capable of displaying a font family having a plurality of fonts.

Techniques for analyzing web pages to determine font subsets

A system of curve generation takes a sequence of control points and constraint codes for each control point, and outputs a curve in which each of the constraints is satisfied. The set of constraints is chosen from the tangent angle, curvature, first derivative of curvature, and second derivative of curvature. The interactive curve design uses as its primitive, a curve whose curvature is a polynomial function of arclength (whose intrinsic equation is a polynomial). At each control point, a choice of G2 curvature continuity (tangent angle and curvature) or G4 curvature continuity (tangent angle and curvature plus first and second derivatives of curvature are continuous) is input. The desired curve is expressed as the solution to the chosen set of constraints.

Method and apparatus for interactive curve generation

A request for a font file including a first font table and a second font table is received. A first entropy encoder is selected, based on characteristics of the first font table, front among a plurality of entropy encoders. A second entropy encoder is selected, based on characteristics of the second font table, front among the plurality of entropy encoders. The first entropy encoder is applied to the first font table. The second entropy encoder is applied to the second font table. Compressed data corresponding to the first and second font tables are combined to generate a compressed font file. The compressed font file is transmitted.

System and method of font compression using selectable entropy encoding

A method for storing information may include determining whether a received data object fits inside a particular one of a plurality of free blocks in a memory bitmap. Each of the plurality of free blocks may include a column of the memory bitmap with a top margin, a bottom margin, and a predetermined width. If the received data object fits, the received data object may be stored in the particular one of the plurality of free blocks, starting at the top margin of the particular one of the plurality of free blocks. The particular one of the plurality of data blocks may be resized by moving the top margin to start below the stored received data object. The determining may include, for each of the plurality of free blocks, a height of the received data object may be compared with a height of each of the free data blocks.

An image rotation system includes a method and apparatus for rotating an image by skewing the image in both the vertical and horizontal directions, and interpolating the image in both the vertical and horizontal directions. A rough vertical skew is performed prior to horizontal skew and prior to any interpolation. Thereafter, more complex processing operations are carried using horizontal scan line pixel streams exclusively. In particular, the horizontal stream processing achieves vertical interpolation, horizontal interpolation corrected for the rough vertical skew, and a fine vertical skew adjustment.

Method and apparatus for image rotation

A halftone screening method includes a method of moire suppression, in which the input image is first screened in a trial screening module. The input image is then subtracted from the trial screened image to produce an error image which contains both the trial screen pattern and the moire pattern introduced by the trial screening process. The error image is filtered in a lowpass filter to remove the trial screen pattern, leaving only the moire pattern, which is then subtracted from the input image to produce a compensated image. Finally, the compensated image is then screened in a final screening module. The moire image component of the compensated image tends to cancel the moire pattern introduced by the final screening module so as to suppress moire patterns in the final screened image. In two alternate embodiments, filter refinements are provided to reduce grayscale distortions and improve moire suppression in the extreme light and shadow regions of the image.

Method and apparatus for suppressing moire patterns

In an error diffusion halftone screen generation system, improved image smoothness in the highlight and shadow areas is obtained by calculating the distance to the nearest previously generated output dot. The square of the distance to the nearest previously generated dot is used as a bias value to effectively modulate the error diffusion threshold. The resulting output provides a halftone with a more uniform texture in the highlight and shadow areas of the screened image. The resulting pattern resembles the pattern of dots produced by tightly packing imaginary circles in the image plane, and placing an output dot at the center of each such tightly packed imaginary circle.

Method and apparatus for error diffusion screening of images with

A method and apparatus for automatically correcting the tone values of a digitally stored image includes compiling a histogram of the relative occurrence of gray values in the stored image in memory. The histogram is processed by adding a constant, taking the square root, and digital filtering. The processed histogram is numerically integrated and then normalized to form a tone correction function. The present tone correction method may be used to tone correct color images by applying separate tone correction functions generated for each of the three color planes independently, or in the alternative, by applying a composite tone correction function corresponding to the average of histograms of the respective individual color planes. A switch is provided to allow the operator to view the results of both methods of automatic tone correction for color images, and choose the best resulting image.

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McDowell, VA, United States of America

Raphael L Levien