Multi-threaded text rendering

• US 8,818,092 B1
• Filed: 09/29/2011
• Issued: 08/26/2014
• Est. Priority Date: 09/29/2011
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Newlin, John
• Primary Examiner(s): Chen, Wenpeng
• Application Number:
  US13/248,854
• Time in Patent Office: 1,062 Days
• Field of Search: None
• US Class Current: 382/167
• CPC Class Codes: G06T 11/00 2D [Two Dimensional] image generation
• CPC Class Codes: G06T 2210/52 Parallel processing
• CPC Class Codes: G09G 5/227 Resolution modifying circuits, e.g. variable screen formats, resolution change between memory contents and display screen
• CPC Class Codes: G09G 5/363 Graphics controllers

Abstract

Methods, systems and computer-readable storage mediums encoded with computer programs executed by one or more processors for rendering text within an image are disclosed. A block of text is segmented into a plurality of text segments, wherein each text segment comprises a sequence of characters. On each of a plurality of threads running in parallel, a text bitmap is generated for a respective text segment from the plurality of text segments, the text bitmap illustrating the sequence of characters for the respective text segment. Each of the text bitmaps are composited with an image bitmap of a source image, wherein the composited image bitmap comprises a rendering of the block of text onto the source image.

Claims

1. A method for rendering text with an image comprising:

receiving, by one or more computing devices, a source image;

receiving, by the one or more computing devices, a separate block of text to be associated with the source image, wherein the block of text is not included in the source image when received;

segmenting, by the one or more computing devices, the block of text into a plurality of text segments, wherein each text segment comprises a sequence of alpha-numeric characters;

on each of a plurality of threads running in parallel, generating a text bitmap for a respective text segment from the plurality of text segments, the text bitmap illustrating the sequence of alpha-numeric characters for the respective text segment; and

compositing, by the one or more computing devices, each of the text bitmaps with an image bitmap of the source image, wherein the composited image bitmap comprises a rendering of the block of text onto the source image.

2. The method of claim 1 wherein the segmenting comprises:

segmenting the block of text, wherein each text segment comprises a complete line of text from the block of text.

3. The method of claim 1 wherein the generating comprises:

creating a thread pool of the plurality of threads based on a number of available processor cores.

4. The method of claim 1 wherein the generating comprises:

determining formatting information for the block of text, wherein the formatting information includes a font-type for rendering the alpha-numeric characters onto the source image.

5. The method of claim 4 wherein the compositing comprises:

compositing each of the text bitmaps onto the image bitmap of the source image based on the formatting information, wherein the composited image bitmap comprises a rendering of the block of text in the font-type onto the source image.

6. The method of claim 1 wherein the generating comprises:

generating a first bitmap for a first text segment using a first thread of the plurality of threads; and

generating a second bitmap for a second text segment using a second thread of the plurality of threads, wherein the first thread and the second thread generate, in parallel, the first bitmap and the second bitmap, respectively.

7. The method of claim 1 wherein the generating comprises, for each character of the alpha-numeric string:

generating a glyph for the character based on corresponding formatting information for the character; and

adding the glyph to the text bitmap of the text block.

8. The method of claim 1 wherein the generating comprises:

determining a space between a first character of the alpha-numeric string of the text block and a second consecutive character of the alpha-numeric string of the text block, wherein the first character immediately precedes the second character by a length of the space; and

adding the space to the text bitmap of the text block.

9. The method of claim 1 wherein the compositing comprises, for each generated text bitmap:

performing an image transfer between the text bitmap of a first text segment and the image bitmap of the source image.

10. The method of claim 1 wherein the source image comprises a view of a geographic area, and wherein the block of text comprises a geographic label describing at least a portion of the view of the geographic area.

11. The method of claim 1, further comprising, for each of the plurality of threads running in parallel, providing an individual character bitmap for each of the alpha-numeric characters included within the respective text segment, the text bitmap being generated by combining the individual character bitmaps.

12. A system for rendering text with an image comprising:

a segmenter configured to receive a source image and a separate block of text to be associated with the source image, the segmenter being further configured to segment the block of text into a plurality of text segments, wherein each text segment comprises a sequence of alpha-numeric characters and wherein the block of text is not included in the source image when received;

a plurality of threads running in parallel, each thread configured to generate a text bitmap for a respective text segment from the plurality of text segments, the text bitmap illustrating the sequence of alpha-numeric characters for the respective text segment; and

a composite engine configured to composite each of the text bitmaps onto an image bitmap of the source image, wherein the composited image bitmap comprises a rendering of the text block onto the source image.

13. The system of claim 12, wherein the segmenter is further configured to determine formatting information for each of the text segments, wherein the formatting information comprises a font-type for rendering the alpha-numeric string on the source Image.

14. The system of claim 13 further comprising:

an assembler configured to generate, based on the composited image bitmap, a resultant image comprising the rendering of the text block on the source image, wherein the alpha-numeric string for each text segment is rendered based on its corresponding formatting information.

15. The system of claim 14 wherein

the segmenter is configured to determine the image bitmap of the source image, based on a decompression of the source image from an image file-type, and

the assembler is configured to compress the composited image bitmap into a resultant image, wherein the resultant image is of the image file-type.

16. The system of claim 12 wherein the segmenter is configured to:

determine an end of a first line of alpha-numeric characters of the text block; and

extract the line of alpha-numeric characters as a first text segment of the plurality of text segments.

17. The system of claim 12 wherein the system is configured to:

determine a number of processors available for the processing; and

create a threadpool of the plurality of threads based on the number available processors.

18. The system of claim 12 wherein the threads of the system are further configured to:

determine a width of the text segment, and generate the text bitmap of the alpha-numeric string, wherein the text bitmap is the width of the text segment.

19. A non-transitory computer readable storage medium having code stored thereon for rendering text that, when executed by one or more processors, causes the one or more processors to:

receive a source image;

receive a separate block, of text to be associated with the source image, wherein the block of text is not included in the source image when received;

segment the block of text into a plurality of text segments, including a first text segment and a second text segment, wherein each text segment comprises a sequence of characters;

determine formatting information, for each text segment, associated with a rendering of the corresponding sequence on the source image;

generate, using a first thread, a first text bitmap for the first text segment;

generate, using a second thread, a second text bitmap for the second text segment, wherein the second thread is configured to generate the second text bitmap in parallel with the first thread generating the first text bitmap; and

composite, the first text bitmap and the second text bitmap onto an image bitmap of the source image, wherein the composited image bitmap comprises a rendering of the block of text onto the source image, wherein each string is rendered based on the formatting information.

20. The non-transitory computer-readable storage medium of claim 19 having code stored thereon for rendering text that, when executed by one or more processors, causes the one or more processors to:

segment the block of text into the plurality of text segments, including the first text segment and the second text segment, wherein each text segment comprises a sequence of non-alpha-numeric characters.