Digital Camera Device Providing Improved Methodology for Rapidly Taking Successive Pictures

• US 20080239093A1
• Filed: 05/06/2008
• Published: 10/02/2008
• Est. Priority Date: 02/07/2001
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: LightSurf Technologies, Inc. (VeriSign, Inc.)
• Inventors: Bodnar, Eric O., Easwar, Venkat V.
• Granted Patent: US 7,847,833 B2
• Time in Patent Office: Days
• US Class Current: 348/222.1
• CPC Class Codes: G06T 9/007 Transform coding, e.g. discrete cosine transform
• CPC Class Codes: H04N 1/2112 using still video cameras
• CPC Class Codes: H04N 1/46 Colour picture communication systems
• CPC Class Codes: H04N 1/64 Systems for the transmission or the storage of the colour picture signal; Details therefor, e.g. coding or decoding means therefor H04N19/00 takes precedence
• CPC Class Codes: H04N 2201/3247 Data linking a set of images to one another, e.g. sequence, burst or continuous capture mode

Abstract

An in-camera two-stage compression implementation is described that reduces the latency between snapshots to a fraction of that otherwise required by other systems that either process complete compression following each snapshot or that incorporate heavy, bulky, and expensive RAM hardware capable of maintaining several raw luminosity records (unprocessed file containing a digital image). In the 1st stage compression the raw luminosity record is quickly, yet partially, compressed to available RAM buffer space to allow a user to expeditiously capture a succeeding image. When the higher-priority processes, the user shooting pictures, and stage one compression subside, a 2nd stage compression, which is slower but more effective, decompresses the earlier partially-compressed images, and re-compresses them for saving in flash memory until they are distributed to a remote platform to be finally converted to the JPEG2000 format.

Claims

1-53. -53. (canceled)

53. A method for compressing digital images upon capture at a digital camera device, the method comprising:

capturing a sequence of digital images;

applying a first fast compression to the sequence of digital images to temporarily compress at least one of the digital images upon capture;

storing the sequence of digital images in an image buffer, wherein at least one of the digital images is compressed with the first fast compression technique.

decompressing at least one of the digital images that were temporarily compressed; and

applying a second, thorough compression technique to the entire sequence of digital images.

54. The method of claim 53, wherein the relatively-fast compression technique requires fewer processing resources for completion than the relatively-thorough compression technique.

55. The method of claim 53, wherein the digital camera device supports multithreaded execution and applying the second, thorough compression technique occurs as a background execution thread.

56. The method of claim 53, wherein the digital camera device supports multithreaded execution and applying the first fast compression technique occurs as a higher-priority thread.

57. The method of claim 53, wherein the sequence of digital images comprises a series of images captured in rapid succession.

58. The method of claim 53, further comprising:

deleting a digital image, after the digital image is temporarily compressed and the temporarily compressed digital image is stored in the image buffer.

59. The method of claim 53, further comprising:

after a given digital image is temporarily compressed;

storing a compressed file of that digital image in a RAM buffer, and

transferring the compressed file from the RAM buffer to flash memory.

60. The method of claim 59, wherein the compressed file is transferred when the RAM buffer is nearly exhausted.

61. The method of claim 53, further comprising:

capturing each digital image as a luminosity record; and

applying pre-compression to each luminosity record, in preparation for compression.

62. The method of claim 61, wherein the pre-compression comprises selected ones of noise smoothing and de-mosaic.

63. The method of claim 53, further comprising:

deferring the relatively-thorough compression technique to a period of time when the user is not providing additional input.

72. The device of claim 63, further comprising:

the second through compression module further to defer the relatively-thorough compression technique to a period of time when the user is not providing additional input.

64. A digital camera device with improved latency time between acquiring pictures, the device comprising:

an image capturing system for capturing a series of digital images to an image buffer;

a first rapid compression module for temporarily compressing at least some of the series of digital images upon capture, thereby freeing up available storage in the image buffer;

a decompression module to decompress the temporarily compressed digital images; and

a second thorough compression module for compressing the series of digital images more thoroughly than that provided by the first compression module.

65. The device of claim 64, wherein the first rapid compression module employs a relatively-fast compression technique that requires fewer processing resources for completion than the second thorough compression technique.

66. The device of claim 64, wherein the digital camera device supports multithreaded execution and wherein the second through compression module employs a compression technique that operates as a background execution thread.

67. The device of claim 64, wherein the sequence of digital images comprises successive pictures rapidly captured at the digital camera device.

68. The device of claim 64, further comprising:

a RAM buffer for storing a given digital image that has been temporarily compressed.

69. The device of claim 64, wherein a digital image is deleted from the image buffer, after the digital image is temporarily compressed and the temporarily compressed digital image is stored in the image buffer.

70. The device of claim 64, wherein the first rapid compression module further includes a module to apply pre-compression to an image captured as a luminosity record, in preparation for compression.

71. The device of claim 70, wherein the pre-compression comprises selected ones of noise smoothing and de-mosaic.