Google Inc.

Brian Cornell

Jennifer Maurer

Daniel Otero

James Darpinian

Sean Egan

A computer-implemented method for verifying identity of an asset can include transmitting, by a first asset, a challenge message at a challenge message transmit time. The challenge message can include a challenge response delay. The method can include receiving, by the first asset, a reply message at a reply message receive time. The reply message can be transmitted from a second asset that is in receipt of the challenge message. The method can include verifying, by the first asset, the second asset based on a comparison of the reply message receive time to a valid reply message receive time span that is based at least in part on the challenge message transmit time and the challenge response delay.

Encrypted response timing for presence detection

A computing device receives, via a communication network, map data including (i) a description of geometries of map features and (ii) a first description of visual characteristics defined separately and independently of the description of the geometries. The computing device applies the visual characteristics to the geometries to render a first digital map. The computing device then receives, via the communication network, a second description of visual characteristics for application to the geometries previously provided to the computing device as part of the map data, and applies the second visual characteristics to the previously received geometries of the plurality of map features to render a second digital map.

Rendering a map using style identifiers

Techniques for merging multiple filters into a single GPU program is described. The system includes a filtering engine, which receives an input to apply a plurality of filters to a source image. The filtering engine identifies a first type of filter and a second type of filter from the input. The filtering engine identifies a supplemental transformation filter from the input, implements the supplemental transformation filter using a custom function to generate a color value at the source image and merges the first type of filter and the second type of filter based on the supplemental transformation filter. Finally, the filtering engine may apply the merged filter on the source image to generate a destination image.

Merging filters for a graphic processing unit

A graphics or image rendering system, such as a map image rendering system, determines a viewing window of a map surface to be displayed, wherein the viewing plane is at an angle of incidence with respect to the map surface. The method generally determines a depth boundary along the map surface where a height projection of a depth increment of a first unit of area is lower than a threshold height increment at a non-zero angle of incidence and at a single zoom level magnification. The method renders the first unit of area within the depth boundary and a second unit of area outside the depth boundary. The first unit of area is rendered at a first density of map data and the second unit of area is rendered at a second density of map data that is lower than the first density of map data.

Derivative-based selection of zones for banded map display

A map server generates a set of base map tiles having vector descriptors, each indicating a geometry of a respective map element, in accordance with a non-raster format for rendering a first map image. The map server provides the base map tiles to the client device. Upon receiving an indication that a specific map image for the selected geographic region is to be rendered at the client device, the map server generates a set of difference map tiles that indicate changes to be made to the set of base map tiles and sends the difference map tiles to the client device for use, along with the set of base map tiles, in rendering the requested specific map image. The client device renders the new map view defined by the difference map tiles without needing to again pre-process all of the features or elements defined in the base map tiles.

Efficient composition and rendering of graphical elements

A graphics or image rendering system, such as a map image rendering system, receives image data from an image database, such as a map database, in the form of vector data having image features defined as sets of vertex data. The vertex data includes location data as well as an attribute reference that references a lookup table, in the form of a texture map, which is sent to or generated in the image rendering system. The attribute reference is then used by an image shader, such as a vertex shader, to determine the specific values for a plurality of vertex attributes or properties, as stored in the look up table. The image rendering system thus processes the vector data in a manner that allows for minimal data to be sent to the image rendering system from the image database as this system enables multiple vertex properties to be specified by a single attribute reference for each vertex data point.

Image shader using style attribute references

A graphics or image rendering system, such as a map image rendering system, receives image data from an image database, such as a map database, in the form of vector data having image features defined as sets of vertex data. The vertex data includes location data as well as an attribute reference pointer variable value that references a first lookup table, in the form of a texture map, which is sent to or generated in the image rendering system. The attribute reference variable value stored in the first lookup table is then used to reference a second lookup table, which may also be in the form of a texture map, to determine the specific values for a plurality of vertex attributes or properties, as stored in the second look up table. The image rendering system thus processes the vector data in a manner that allows for minimal data to be sent to the image rendering system from the image database or between processors of the image rendering device, as this system enables multiple vertex properties to be specified and easily changed by changing a single attribute reference pointer variable value for each vertex data point.

Image shader using two-tiered lookup table for implementing style attribute references

A graphics or image rendering system, such as a map image rendering system, receives image data from an image database, such as a map database, in the form of vector data having image object elements defined as sets of vertex data points. The image rendering system stores and tabulates the vertex data points used to render an image object element. A code specifies a number of vertex data points that can be obtained from a tracking table as well as an amount of vertex data points to be sent from the image database. An image rendering engine uses the stored and transmitted vertex data points to render the image object element to be displayed.

Optimized data communication system and method for an image rendering system

Rendering map tiles with style data for zoom levels other than the style data intended for that tile at its nominal zoom level can be used to avoid abrupt changes between map tiles. Particularly when changing zoom levels, use of styles from more than one level may create an uneven look. To address this, either the new data may be displayed with the style for the previous zoom level or the old data may be presented with the style for the new zoom level style until all tiles for the new zoom level are received. At that time, all the map tiles may be displayed using the style for the new zoom level along with the map data intended for that zoom level. Displaying map tiles at a first zoom level using a progression of styles from other zoom levels may also be used when creating a perspective view map.

Seamless vector map tiles across multiple zoom levels

A graphics or image rendering system, such as a map image rendering system, receives image data from an image database in the form of vector data that defines various image objects, such as roads, geographical boundaries, etc., and textures defining text strings to be displayed on the image to provide, for example, labels for the image objects. The imaging rendering system renders the images such that the individual characters of the text strings are placed on the image following a multi-segmented or curved line. This rendering system enables text strings to be placed on a map image so that the text follows the center line of a curved or angled road or other image feature without knowing the specifics of the curvature of the line along which the text will be placed when creating the texture that stores the text string information. This feature provides enhanced visual properties within a map image as it allows, for example, road names to be placed anywhere inside a road following the curvature of the road, thus providing a pleasing visual effect within the map image.

Rendering a text image following a line

Multiple individually renderable map elements, each representing a respective physical entity in a geographic area, are rendered to generate a digital map of the geographic area. A description of an aggregate map feature that includes several but not all of the multiple map elements is received. The several map elements represent physical entities that form a common administrative unit. A selection of one of the several map elements is received via the user interface. In response to receiving the selection, the several map elements included in the aggregate map feature are automatically selected, and an indication that the aggregate map feature has been selected is provided on the user interface.

Managing map elements using aggregate feature identifiers

A graphics or image rendering system, such as a map image rendering system, may receive map data associated with a set of zoom levels, where the map data includes style attribute data corresponding to various features of a map surface at corresponding zoom levels. The system may interpolate at least some of the style parameter values from the received map data to provide style parameter values over a range of zoom levels.

Map rendering using interpolation of style parameters across zoom levels

A graphics or image rendering system, such as a map image rendering system, receives image data from an image database in the form of vector data that defines various image objects, such as roads, geographical boundaries, etc., and textures defining text strings to be displayed on the image to provide, for example, labels for the image objects. The imaging rendering system renders the images such that the individual characters of the text strings are placed on the image following a multi-segmented or curved line. In doing so, the image rendering system creates and reads a texture map that stores pixelated text characters of the text strings to be rendered in the image as a set of glyphs and that also stores first encoding data defining the center position of each text character as stored in a glyph and second encoding data referencing the location of the glyph to be used as the text character. This center position encoding enables the system to determine whether, in any particular instance, a text character of a text string should be rendered in the image at a particular position along the line or at a different position along the line while maximizing the storage efficiency of the texture map used to store the text string by allowing text characters repeated in a text string to be stored only once in the texture map.

Rendering a text image using texture map character center encoding with character reference encoding

A graphics or image rendering system, such as a map image rendering system, receives image data from an image database in the form of vector data that defines various image objects, such as roads, boundaries, etc., which are to be rendered as straight lines within an image. The imaging rendering system renders the image objects by applying an anti-aliasing technique that determines varying pixel color values at or near the edges of each straight line to be rendered on the image, so as to obtain a pleasing visual effect when rendering a road or other boundary in any orientation on the image screen. The anti-aliasing technique determines a scaling vector having values dependent on the location of a particular pixel in the image along the normal to the straight line forming a road and determines a pixel color value at each pixel location associated with the road based on this scaling vector, such that the pixel color value at each pixel in or near the line is proportional to a component of the scaling vector. This technique produces a more gradual transition in pixel color values from a non-road location to a road location in the image, and thus provides a non-aliased rendering of the road regardless of the orientation or direction in which the road is being rendered in the image.

Anti-aliasing of straight lines within a map image

A plurality of graphics objects are assigned to a quad-tree structure corresponding to a display. It is determined whether another graphics object overlaps with a display area corresponding to a node of the quad-tree structure. When the other graphics object overlaps with the display area, it is determined whether the other graphics object intersects with any graphics objects belonging to the node.

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Kenmore, WA, United States of America

Brian Cornell