摘要:
A digital imaging system is described that provides techniques for reducing the amount of processing power required by a given digital camera device and for reducing the bandwidth required for transmitting image information to a target platform. The system defers and/or distributes the processing between the digital imager (i.e., digital camera itself) and the target platform that the digital imager will ultimately be connected to. In this manner, the system is able to decrease the actual computation that occurs at the digital imager. Instead, the system only performs a partial computation at the digital imager device and completes the computation somewhere else, such as at a target computing device (e.g., desktop computer) where time and size are not an issue (relative to the imager). By deferring resource-intensive computations, the present invention substantially reduces the processor requirements and concomitant battery requirements for digital cameras. Further, by adopting an image strategy optimized for compression (compressed luminosity record), the present invention decreases the bandwidth requirements for transmitting images, thereby facilitating the wireless transmission of digital camera images.
摘要:
A method and system for efficient buffer rendering. An object mask, typically a character font mask, is aligned with a memory tiling arrangement (1102). A tile map is generated (1104) to indicate active tiles. An active tile is selected (1106) and the portion of the buffer corresponding to the active tile is transferred (1108) from a first memory, typically an off-chip memory, to a second memory, typically an on-chip memory to allow a processor to render the band buffer tile. The portion of the band buffer is rendered (1110) and returned (1112) to the first memory. The next active tile is selected and the process continues until all active tiles have been rendered (1114).
摘要:
This invention cures many inefficiencies with known scan conversion methods. This invention employs an edge array rather than a set linked list from an array of pointers equal in number to the number of scan lines. This invention thus eliminates storage of linked list pointers which in the prior art included many null pointers resulting in better memory utilization. This invention sorts the active edge table only at edge intersections and vertices, thus eliminating much unneeded sorting. This invention permits integrated clipping of a subject polygon by a clip polygon and forming trapezoids filling the clipped area by activating trapezoid formation at every vertex of either polygon and at every edge intersection. This process saves code space and computer processing time. This invention efficiently utilizes the resources of a multiprocessor integrated circuit by spawning of subtasks from a RISC type processor to one or more DSP type processors.
摘要:
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.
摘要:
This invention is a computer implemented method of approximating a gray scale tone with a more limited range image producer. One of a plurality of tone curves is associated with each pixel of a screening matrix. The plural tone curves are approximated by a polynomial and the polynominal coefficients are determined. The polynomial coefficients are stored in a look-up table. Each pixel of an image is mapped to a corresponding pixel of the screening matrix. For each pixel the corresponding polynomial coefficients approximating the tone curve are recalled and used to compute a pixel output value from a pixel input value. The polynomial is preferrably of the third degree polynomial and in a form easily computed using a digital signal processor with a hardware multiplier and arithmetic logic unit. Screening in this manner requires less memory storing the screening data than the prior art pure look-up table screening.
摘要:
A screening method in a printer for approximating a gray scale tone with a more limited range image producer using a tree search. An input pixel packed data word is compared with a second data word packed with threshold values. The result of the comparison enables selection of a next second data word with thresholds is a narrower range. This process repeats until a comparison with a second data word having adjacent threshold values. The comparing is preferably performed by subtracting the second data word from the first data word in a splittable arithmetic logic unit and storing respective carry outs from each section. The selection of the next second data word uses the stored carry outs from each section. The next second data word can be determined by extracting a left most one of the stored carry outs for use as an index into a table. Alternatively, the stored carry outs can be used directly as an index into a table. An output pixel value is determined for each pixel. This may be computed from the stored carry outs or extracted from a table.
摘要:
A block based hybrid compression method with compression ratio control. The input page is classified as SOLID, TEXT, SATURATED TEXT or IMAGE type, and the compression method most appropriate for each class is chosen on a block by block basis. The compression methods shown include Block Truncation Coding, Lossy or Lossless Differential Pulse Code Modulation, Run Length Coding and Discrete Cosine Transforms, but other algorithms may also be used. The compression ratio is dynamically controlled by selection of the compression algorithm, and by the adjustment of control parameters on a block by block or a row of blocks basis. The methods shown will execute very efficiently on a Texas Instruments TMS302C82 multiprocessing Digital Signal Processor.
摘要:
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.
摘要:
A media spooler system is described that provides a methodology for efficient transmission of media content from client devices, such transmission of digital images from wireless digital cameras. The media spooler or gateway addresses wireless transmission problems by acting as a protocol gateway between a thin-client device and a target host or server (supported by a server infrastructure). More particularly, the media spooler of the present invention acts as a protocol gateway between thin-client devices (e.g., “mobile visual communicator” in the form of a wireless digital camera) and server infrastructure (e.g., server-based computer systems or “Web servers” of a photographic service provider). This task entails accepting multiple, simultaneous connections from various client devices (e.g., wireless digital cameras), extracting information from those devices (e.g., digital photographs or other media content), and then uploading that information to the target server infrastructure. In basic operation, the media spooler queries each client device for the information (e.g., media, such as pictures) the client device thinks should uploaded, and then the media spooler queries the server infrastructure for the subset of pictures that have not been already uploaded. This improved coordination or synchronization of information between a device and target host allows for efficient recovery of dropped cellular data calls by essentially allowing the media spooler to “pick up where it left off.”
摘要:
This invention is a method of multilevel dither screening in a printer. Plural pixel values are packed into equal sections of a first data word. Corresponding dither values are packed into the equal sections of a second data word. These first and second data words are added in an arithmetic logic unit selectively spilt into the equal sections. Each section of the sum data word is saturated to all 1's. A predetermined number of least significant bits of the saturated sections are truncated. The resulting normalized pixel values are quantized into a limited set of threshold ranges. This dithering process serves to introduce an amount of scattering to the input pixel values to reduce quantization and pixelation artifacts in the final printed product.