HK1176155B - Response time compensation - Google Patents

Description

Response time compensation

Technical Field

The present invention relates to response time compensation for displays, and more particularly, to a method and apparatus for compressing information for response time compensation of display units.

Background

The liquid crystal display displays an image by optical change, which is achieved by injecting and aligning a liquid crystal display cell between two glass plates, and then changing the alignment of the liquid crystal display cell by applying a voltage. In the liquid crystal display, the current image overlaps the previous image due to the slow response time to cause a picture blur. For example, when the display refresh rate is 60 Hz, a frame is typically displayed for about 16.7 ms. When a voltage is applied across the liquid crystal material, a physical torque will be generated that will start to reposition the liquid crystal material. The greater the torque (voltage), the faster the response of the liquid crystal material, and the faster its further movement. The response of the material can be improved (and thus the colour change more accurate) by adjusting the torque applied to the liquid crystal material. Slow pixel response will blur the visual effect.

In order to improve the response speed of the liquid crystal display, response time compensation methods such as two-frame overdrive (overdrive) and multi-frame overdrive may be used. When the two-frame overdrive is used, a difference value of a pixel value of a previous frame of an arbitrary pixel and a pixel value of a current frame of the pixel may be obtained, and a sum value proportional to the difference value and the pixel value of the current frame may be generated. These values are then used as lookup table (with or without interpolation) indices to derive the optimal logical drive values. Multi-frame overdrive uses a similar approach to two-frame overdrive, but uses two consecutive previous frames instead of a single previous frame. In order to use either overdrive technique, the previous frame pixels must be stored in memory.

Therefore, among other reasons, it is desirable to minimize the size of the previous frame stored in memory when response time compensation is used in order to improve the performance of the liquid crystal display.

Drawings

The invention may be better understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements:

FIG. 1 is an exemplary functional block diagram of an apparatus including a response time compensation and compression system;

FIG. 2 is a flow chart depicting exemplary operational steps of the response time compensation and compression system;

FIG. 3 is a flow chart depicting exemplary operational steps for a response time compensation and compression system using display mode information;

FIG. 4 is an exemplary functional block diagram of a compression module of the response time compensation and compression system;

FIG. 5 is a flow chart depicting exemplary steps of operation of an intra motion prediction module of the response time compensation and compression system;

FIG. 6 is an exemplary functional block diagram of a quantization factor generation module of the response time compensation and compression system;

FIG. 7 is a flow chart depicting exemplary steps of a quantization factor generation module;

FIG. 8 is an exemplary functional block diagram of a decompression module of the response time compensation and compression system;

FIG. 9 is a flowchart depicting exemplary steps of a decompression module;

FIG. 10 is another flow chart depicting exemplary operational steps of the response time compensation and compression system;

Detailed Description

In one example, an apparatus for a response time compensation system includes a plurality of complexity modules that determine a plurality of complexity values based on current image information and previous image information, and a motion vector module. The motion vector module determines a desired complexity value based on a lowest complexity value, the motion vector based on a determination of a desired motion vector for a lowest value of the plurality of complexity values. The desired complexity value and the desired motion vector are used to compress the current picture information into a compressed bitstream. The response time compensation system uses the compressed bitstream to provide display unit response time compensation information for a display. Related methods are also disclosed herein.

Among other advantages, the method and apparatus provide a pre-compressed frame of image information that minimizes information stored to memory when response time compensation is used to improve display performance. Furthermore, power consumption may be minimized by selectively turning off and/or bypassing the compression module, the decompression module, and/or the display unit response time compensation module that are not needed due to the display mode of the display. Other advantages of the invention will be apparent to those skilled in the art.

In one example, at least one of said complexity values is based on an average absolute difference of a plurality of said blocks of image information, and at least one of said plurality of complexity values is based on an average absolute difference of a plurality of said blocks of previous image information.

In one example, the intra-motion prediction apparatus includes a motion prediction displacement module. The motion prediction movement module provides the previous image information by temporally and spatially shifting the current image information.

In one example, the intra motion prediction apparatus is included in an integrated circuit. In one example, the display and the internal motion prediction means are comprised in a device.

In one example, an apparatus includes a control module that provides error control information based on a target number of bits and an actual number of bits required to pack at least one compressed block of image information, and an action module. The action module provides a quantization factor based on the error control information and a complexity value of at least one of the compressed blocks of image information. The quantization factor is used to pack at least one compressed block of image information into a bitstream comprising the target number of bits. Related methods are also disclosed herein.

In addition to the above advantages, the method and apparatus also provide a quantization factor for packing image information into a compressed bitstream so that information stored in a memory can be minimized when response time compensation is used to improve display performance. Other advantages of the invention will be apparent to those skilled in the art.

In one example, the control module is a proportional integral derivative control module. In one example, the action module may be operable to provide the quantization factor by accessing a predetermined look-up table. In one example, the predetermined look-up table includes the complex value, an error value based on the error control information, and the quantization factor. In one example, the error control information is based on a difference between the target number of bits and the actual number of bits required to pack at least one compressed block of image information.

In one example, an apparatus includes a compression module, a decompression module, a display unit response time compensation module, and a bypass control module. The compression module compresses a current frame to generate a compressed previous frame of image information. The decompression module decompresses the pre-compressed frame of image information to generate a pre-decompressed frame of image information. The display unit response time compensation module provides display compensation information for a display based on the current frame and the decompressed previous frame. A bypass control module causes the current frame information to selectively bypass the compression module, decompression compression module, and/or the display element response time compensation module based on display mode information. Related methods are also disclosed.

In addition to the above advantages, the method and apparatus also provide a pre-compressed frame of image information that minimizes information stored in memory when response time compensation is used to improve display performance. Furthermore, power consumption may be minimized by selectively turning off and/or bypassing the compression module, decompression module, and/or the display element response time compensation module that are not needed due to the display mode of the display. Other advantages of the invention will be apparent to those skilled in the art.

In one example, the display mode information includes a dynamic image mode, a static image mode, a lost input information mode, and/or a low power consumption mode.

In one example, the display unit response time compensation module outputs the pre-decompressed frame when the display mode information indicates the lost input information mode.

In one example, the bypass control module selectively turns off the compression module, the decompression module, and/or the display unit response time compensation module based on the display mode information.

In one example, the display image response time compensation includes a first multiplexer that transmits a current image to the display element response time compensation module or an output module operatively connected to the display in response to bypass control information received from the bypass control module.

In one example, the display image response time compensation includes a second multiplexer that transmits the current frame to the compression module in response to bypass control information received from the bypass control module.

In one example, an apparatus includes a display and the display image response time compensation system.

In one example, the compression module includes a quantization factor module, a transform quantization module, and an entropy module. The quantization factor provides a quantization factor based on a spatial domain image information complexity value. The transform quantization transforms the spatial domain image into a quantized frequency domain image based on the quantization factor. The entropy module variable length encodes the quantized frequency domain information to generate compressed image information. In one example, the display unit response time compensation module provides display unit response time compensation information based on the compressed image information. In one example, the compression module includes an intra prediction module.

In one example, the decompression module includes an inverse entropy module and an inverse transform quantization module. The inverse entropy module generates the decompressed image information by variable length decoding the compressed image information. The inverse transform quantization module provides decompressed spatial image information by transforming the decompressed image information. The display unit response time compensation module may be operative to provide display unit response time compensation information based on the decompressed spatial image information. In one example, the decompression module includes an internal compensation module.

As used herein, the term module may include a circuit, one or more processors (e.g., shared, dedicated, or group of processors including but not limited to microprocessors, digital signal processors, or central processing units), memory that executes one or more software or firmware programs, combinational logic circuits, application specific integrated circuits, and/or other suitable components that provide the described functionality. Furthermore, as known to those skilled in the art, the operation, design, and construction of a "module" can be described by, for example, Verilog, VHDL, or other suitable hardware description languages. Unless otherwise specified, the term "shut down" refers to removing (or reducing) the power to the module to render it inoperative. Furthermore, the term "turn on" refers to applying (or raising) the power to the module to bring it into operation.

As shown in fig. 1, an apparatus 100 is shown that includes a liquid crystal display 102, such as a liquid crystal display television, a liquid crystal display monitor, a liquid crystal display panel, a mobile phone, a printer, a personal digital secretary, and/or other suitable device. The apparatus 100 includes a response time compensation and compression system 104 and a display 102. The response time compensation and compression system 104 includes an input module 106, a bypass control module 108, a color adjustment module 110, a first color conversion module 112, a second color conversion module 114, a compression module 116, a decompression module 118, a display unit response compensation (RTC) module 120, a memory 122, and an output module 124.

The input module 114 receives image information 126 including at least one color component such as red, green, and/or blue (RGB). The output module 114 sends image information 128 to the color adjustment module 110 for correcting color content (e.g., gamma, white balance) and to the first multiplexer 130, which operates as a bypass. Color adjustment module 110 performs color correction on image information 128 and provides adjusted color information 132 to multiplexer 130, as is known in the art. Multiplexer 130 provides combined color information 134 to color conversion module 112 based on image information 128 and/or adjusted color information 132.

The color conversion module 112 converts the combined color information 134 from RGB information to YCrCb information 136 using YCrCb (luminance hue saturation) conversion, which is known in the art. When converting to YCrCb information 136, the color conversion module 112 maintains sufficient color depth information to ensure that the color conversion module 114 can obtain accurate inverse conversion.

The compression module 116 compresses the current frame of the YCrCb information 136 to provide compressed information 138, the compressed information 138 being stored in memory as a previous frame 140 and a previous frame 142 (e.g., a previous frame of the previous frame 140). The compression module 116 provides compressed information 138 using intra prediction in conjunction with frequency domain quantization and variable length compression methods. The number of stored frames may be predetermined based on the needs of the display unit RTC module 120.

As will be described in further detail below, the compression module 116 determines the complex value of the YCrCb information 136 based on the block mean absolute difference value of the YCrCb information 136. The compression module 116 also determines the pre-processed image information that it subsequently uses (subsequent use) based on the block mean absolute difference of the YCrCb information 136. The compression module 116 transforms the YCrCb information 136 from spatial domain information to frequency domain information. In addition, the compression module 116 determines a fast Quantization Factor (QF) based on the complexity value of the selected block of image information, the quantization factor table information 144 of the quantization factor table 146, and the difference between the target number of bits 147 that can be predetermined, allocated to pack the compressed information 138 into a bitstream, and the actual number of bits used to pack the compressed information 138 into a bitstream. In addition, the compression module 116 quantizes the frequency domain information using the quantization factor table information 144 and then variable length encodes the quantized frequency domain information using the entropy information 148 from the entropy table 150.

The decompression module 118 receives the pre-compressed information 152 from the memory 122. The previous compression information 152 is based on the previous frame 140(n-1) when two-frame overdrive is used, or the previous compression information 152 is based on the previous frame 140(n-1) and the previous frame 142(n-2) when multi-frame overdrive is used. The decompression module 118 decompresses the pre-compressed information 152 based on the entropy information 154 and the quantization factor from the entropy table 150 to provide pre-decompressed image information 156 to the second color conversion module 114. The second color conversion module 114 converts the decompressed pre-image information 156 from YCrCb information to pre-image RGB information 158 using an inverse YCrCb transform as is known in the art.

The display element RTC module 120 may perform any known response time compensation method, such as two-frame overdrive, multiple-frame overdrive, and/or any other suitable corresponding time compensation method. The display element RTC module 120 provides display element RTC information 160 based on the previous image RGB information 158 and the current frame of combined color information 134, which combined color information 13 is 4 based on either the adjustment color information 132 or the image information 128.

For example, when using two-frame overdrive, the display element RTC module 120 determines the difference between the pixel value of the previous frame 140(n-1) and any pixel of the current frame of the combined color information 134. A sum value proportional to the difference value and the pixel value of the current frame is output as the real cell RTC information 160. These values are typically used as inputs to a look-up table to determine the correct display drive level. When using multi-frame overdrive, the display element RTC module 120 uses both the previous frame 140(n-1) and the previous frame 142(n-2) to provide the display element RTC information 160.

The second multiplexer 162 provides display element information 164 based on the combined color information 134, the front image RGB information 158, or the display element RTC information 160. The output module 124 receives the display unit information 164 and provides display information 166 to the display 102. The display 102 displays an image 168 based on the display information 166, as is known in the art.

The bypass control module 108 selectively controls the multiplexers 130, 162 based on changes in the reality mode information 106, 170 by bypassing the control information 172, 174, 176 to cause the image information 128 to bypass the color adjustment module 110 and/or the color conversion module 112, the second color conversion module 114, the compression module 116, the decompression module 118, the display unit RTC module 120, and the memory 122. In some embodiments, the bypass control information 172, 174, 176 can also be used to select to shut down the color conversion module 112, the compression module 116, the decompression module 118, the second color conversion module 114, and/or the display unit RTC module 120 when the respective module 112, 114, 116, 118, 120 is bypassed.

In some embodiments, the display mode information 168 is based on the image information 126. In other embodiments, the display mode information 170 can be received from a low power mode driver (not shown) operating from a processor (not shown) of the device 100. The display mode information 168, 170 can include different operating modes of the apparatus 100, such as a dynamic image mode (e.g., the image information 126 is a moving image, such as a video image), a static image mode (e.g., the image 126 is a static image, such as a photograph), a lost input information mode (e.g., the image information 126 does not contain valid image information), a low power mode (e.g., the low power drive causes the apparatus to operate in a low power mode), and/or other suitable operating modes of the apparatus 100.

When the display mode information 168, 170 changes to either the lost input information mode or the low power mode, the bypass control module 108 controls the multiplexer 162 to base the display element information 164 only on the previous image RGB information 158 and not on the current frame of the previous image RGB information 158 and the combined color information 134.

When the display mode information 168, 170 changes to still image mode, the bypass control module 108 controls the multiplexer 162 to base the display element information 164 on the combined color information 134 (e.g., still image) instead of the previous image RGB information 158.

As such, the bypass control module 108 can reduce response time compensation and power consumption of the compression system 104 by selectively shutting down and/or bypassing the compression module 116, the decompression module 118, and/or the display element RTC module 120 when such modules are not needed for use due to a change in display mode conditions. Additional power savings can also be achieved by upstream components (not shown) without refreshing the display 102 through the input module 106.

As shown in FIG. 2, exemplary steps are defined at 200 that the response time compensation and compression system 104 generally uses to provide the display element RTC information 160. The process begins at step 202 when the compression module 116 receives the YCrCb information 136. In step 204, the compression module 116 determines a quantization factor based on a complexity value based on the average absolute difference value of the spatial domain YCrCb information 136. In step 206, the compression module 116 converts the spatial domain YCrCb information 136 into quantized frequency domain information based on the quantization factor. In step 208, the compression module 116 variable-length encodes the quantized frequency information to generate compressed information 138. In step 210, the display unit RTC module 120 generates the display unit RTC information 160 based on the front image RGB information 158, the front image RGB information 158 being based on the compressed image information 138. The process ends at step 212.

As shown in fig. 3, the general exemplary steps for the response time compensation and compression system 104 to use the display mode information 168, 170 are defined at 300. The process starts at step 302. In steps 304, 312, and 316, the bypass control module 108 determines in which mode the display 102 is operating based on the display mode information 168, 170. If the display mode information 168, 170 is dynamic image mode (e.g., video) in step 304, the bypass control module 108 controls the multiplexers 130, 162 such that the display element RTC module 120 provides the display element RTC information 160 based on the front image RGB information 158 and the combined color information 134, and the process ends in step 310.

If the bypass control module 108 display module information 168, 170 does not indicate a dynamic mode (e.g., video) in step 304, the bypass control module 108 determines whether the display mode information 168, 170 indicates a still image mode in step 312. If the display 102 is operating in the still image mode at step 314, the bypass control module 108 controls the multiplexers 130, 162 such that the display element RTC module 120 is bypassed and such that the display element information 164 is based on the current frame of the combined color information 134, and the process ends at step 308.

If the bypass control module 108 determines that the display is not operating in the still image mode in step 312, the bypass control module 108 determines whether the display is operating in the lost input information mode or the low energy mode in step 316. If the display 102 is operating in the lost input information mode or the low power mode, the bypass control module 108 controls the multiplexers 130, 162 in step 318 so that the output module 124 has the previous image RGB information 158 based on the decompressed previous image information 156, and the process ends in step 308.

Referring to fig. 4, a functional block diagram of the compression module 116 is shown. The compression module 116 includes an intra motion prediction module 400, a quantization factor generation module 402, a transform quantization module 404, an inverse transform quantization module 439, a motion prediction module 408, an entropy module 410, and a packing module 412.

The intra motion prediction module 400 determines the desired (e.g., best) motion vector information 414 based on the current YCrCb information 136 and the previous image information 416. In addition, the intra motion prediction module 400 provides a complexity value 418 for the image information 136 or the pre-image information 416.

The intra motion prediction module 400 includes a plurality of complexity modules 420 and a motion vector module 422. In some embodiments, there are 28 complex modules 420 in total, however only more or less complex modules 420 are used. The motion vector module 422 provides the complexity value 418 based on the image information 136 and/or the previous image information 416, which previous image information 416 continuously yields the lowest complexity value.

The complexity module 420 sums the average absolute difference between each block of image information 136 (or prior image information 424) to determine a plurality of complexity values 426. The motion vector module 422 provides the desired (i.e., optimal) motion vector information 414 by selecting the previous motion vector corresponding to the desired motion vector information 414 having the lowest value of the pair of complexity values 426. In addition, the motion vector module 422 provides processed image information 428 including current YCrBr information 136 and previous image difference information 424.

As will be described in further detail below, the quantization factor generation module 402 determines the quantization factor information 430 based on the target number of bits 147, the number of used bits 432 to pack the compressed information 138 into a bitstream, the complexity value 418, and the quantization factor table information 144 of the quantization factor table 146

The transform quantization module 404 provides quantized frequency domain information 432 based on the processed image information 428 and the quantization factor information 430. More specifically, the transform module 433 receives the processed image information 428 in the spatial domain and transforms the processed image information 428 into frequency-domain image information 434. Transform module 433 may transform processed image information 428 into frequency-domain image information 434 using any suitable transform method, such as a discrete cosine transform, an integer transform, or any other suitable transform known in the art. The quantization module 436 provides quantized frequency domain information 432 based on the quantization factor information 430 and the frequency domain image information 434.

The entropy module 410 variable-length codes the quantized frequency domain information 432 into variable-length coded information 438 using the entropy information 144 from the entropy table 150. In the prior art, entropy coding is a data compression scheme that assigns codes to symbols such that the probability of a symbol matches the length of the code. To achieve the maximum compression ratio, the shortest code length may be assigned to the most commonly used symbols. The entropy module 410 may use an entropy table 150, which entropy table 150 includes predetermined symbols and code values determined using huffman coding in the art. Although huffman coding is used in this example, other known entropy coding methods can be used, such as arithmetic coding.

The packing module 412 receives the variable length coding information 438 and packs the variable length coding information 438, the motion vector information 414, and the quantization factor information 430 into a bitstream of compressed image information 138. In some embodiments, the motion vector information 414 and the quantization factor information 430 are also entropy encoded before being packed into a bitstream of compressed image information 138.

Further, the packing module 412 provides the number of used bits 432 to pack the compressed information 138 into a bitstream. As mentioned previously, the quantization factor generation module 402 determines the quantization factor information 430 using the number of used bits 432 that pack the compressed information 138 into a bitstream.

The inverse transform quantization module 406 provides non-quantized spatial domain image information 440 based on the quantized frequency domain information 432. More specifically, the inverse quantization module 439 provides non-quantized frequency domain information 422 based on quantized frequency domain information 432 and quantization factor information 430. The inverse transform module 444 receives the unquantized frequency domain information 442 and transforms the unquantized frequency domain information 442 into the unquantized spatial domain image information 440. The inverse transform module 444 uses an inverse transform of the transform used by the transform module 433, such as an inverse discrete cosine transform or an integer transform as is known in the art.

The motion prediction module 408 provides the pre-image information 416 based on the non-quantized spatial domain image information 440. More specifically, the motion prediction module 408 provides the pre-image information 416 by pre-displacement non-quantized spatial domain image information 440, thereby providing "temporally and spatially displaced" image information based on the pre-image information 136.

The motion prediction module 408 includes a motion prediction displacement module 450, a displacement selection module 452, and a summation module 454. The summation module 454 provides compensated image information 458 based on the sum of the non-quantized spatial domain image information 440 and the "temporally and spatially shifted" pre-processed image information 456. The motion prediction displacement module 450 provides pre-image information 416 based on non-quantized spatial domain image information 440 and pre-processed image information 456. The displacement selection module 452 provides pre-processed image information 456 based on temporally and spatially displaced image information 458.

As shown in fig. 5, the general exemplary steps performed by the intra motion prediction module 400 when determining the motion vector 414 and the complexity value 418 are defined at 500. The process begins at step 502 where the complexity module 420 receives the current YCrCb image information 136. In step 504, the plurality of complexity modules 420 determine a plurality of complexity values 426 based on the current YCrBr information 136 and the previous image information 416. In step 506, the motion vector module 422 determines the desired complexity value 418 based on the lowest value of the plurality of complexity values 426. In step 508, the motion vector module determines the desired (e.g., optimal) motion vector based on the lowest value of the plurality of complexity values 426. As discussed previously, the response time compensation and compression system 104 uses the desired complexity value 418 and the desired motion vector 414 to compress the current YCrBr image information 136 into a compressed bitstream of compressed information 138 that is used to provide the display unit RTC information 160 for the display 102. The process ends at step 510.

As shown in fig. 6, fig. 6 illustrates an exemplary functional block diagram of the quantization factor generation module 402. The quantization factor generation module 402 includes a control module 600 and an action module 602. In some embodiments, the control module is a proportional-integral-derivative (PID) controller that is responsive to pre-error control information as is known in the art. Other controllers are also possible, such as a proportional-integral controller, a proportional-derivative controller, or other suitable controller.

The control module 600 provides error control information 604 based on the target number of bits 147 and the number of used bits 432 to pack the compressed information 138 into a bitstream. More specifically, the control module 600 provides the error control information 604 based on the difference 606 between the target number of bits 147 and the number of used bits 432 that pack the compressed information 138 into a bitstream. Although only external functions of control module 600 are described, control module 600 can include a difference module 608 that determines difference 606.

The action module 602 provides the quantization factor information 430 based on the error control information 604 and the complexity value 418. More specifically, the action module 602 accesses the quantization factor table 146 using the quantization factor table query 610 (including the error control information 604 and the complex value 418) and retrieves the quantization factor table information 144 based on the error control information 604 and the complex value 418. Likewise, the quantization factor table 146 may be a predetermined look-up table including primarily empirically determined quantization factors based on the error control information 604 and the complexity value 418. The quantization factor table 146 can return the quantization factor information 430 by an index value based on the complexity value 418 and the error control information 604. In addition, the action module 602 can insert a quantization factor when the values on the quantization factor table cannot match one-to-one.

As shown in fig. 7, the general exemplary steps by which the quantization factor generation module 402 provides quantization factor information 430 are defined at 700. The process begins at step 702. In step 704, the control module 600 provides the error control information 604 based on the target number of bits 147 and the number of used bits 432 to pack the compressed information 138 into a bitstream. In step 706, the action module 602 provides the quantization factor information 430 based on the error control information 604 and the complexity value 418. As previously described, the action module 602 accesses the quantization factor table 146 to obtain the quantization factor table information 144 based on the error control information 604 and the complexity value 418 to determine the quantization factor information 430. The process ends at step 708.

As shown in fig. 8, fig. 8 illustrates a functional block diagram of the decompression module 118. The decompression module 118 essentially performs the inverse operation of the compression module 116. The inverse compression module 118 does not need to determine the quantization factor because the compression module 116 provides the quantization factor information 430 to the decompression module 118 via the pre-compression information 152. The decompression module 118 includes an unpacking module 800, an inverse entropy module 802, an inverse transform quantization module 804, and a motion compensation module 806. The unpacking module 800 receives the bitstream of the pre-compression information 152 from the memory 122 and unpacks the bitstream to obtain unpacked pre-compression information 810(unpacked prior compression information 810). In addition, the unpacking module 800 unpacks the pre-compression information 152 to obtain the motion vector information 414 and the quantization factor information 430.

The inverse entropy module 802 variable length decodes the unpacked compressed information 810 based on the entropy information 151 to provide decoded quantized image information 812, the entropy information 151 being from the entropy table 150. The inverse entropy module 802 essentially performs the inverse operation of the entropy module 410 to variable length decode the unpacked compressed image information 810.

The inverse transform quantization module 804 provides non-quantized spatial domain image information 814 based on the decoded quantized image information 812. More specifically, the inverse quantization module 816 provides non-quantized frequency domain information 818 based on the decoded quantized image information 812 and the quantization factor information 430 in the frequency domain. The inverse transform module 820 receives the unquantized frequency domain information 818 and transforms the unquantized frequency domain information 818 into the unquantized spatial domain image information 814. The inverse transform module 820 uses an inverse transform of the transform used by the transform module 433, such as an inverse discrete cosine transform or an integer transform as in the prior art.

The motion compensation module 806 includes a motion compensation module 822, a displacement selection module 824, and a summation module 826. The summation module 82 provides the image information 156 based on the sum of the non-quantized spatial domain image information 814 and the "temporally and spatially shifted" pre-processed image information 828. The motion compensation module 822 provides temporal and spatial displacement image information 830 based on the non-quantized spatial domain image information 814 and the pre-processed image information 828. The displacement selection module 824 provides pre-processed image information 828 based on the temporally and spatially displaced image information 830 and the motion vector information 414.

As shown in fig. 9, the general exemplary steps taken by the decompression module 118 are defined at 900. The process starts at step 902. In step 904, the unpacking module 800 unpacks the compressed information 152 to provide the motion vector information 414, the quantization factor information 430, and unpacked compressed image information 810. In step 906, the inverse entropy module 802 variable length decodes the unpacked compressed image information 810 based on the entropy information 154 from the entropy table 150 to provide decoded quantized image information 812. In step 908, the inverse transform quantization module 804 transforms the decoded quantized image information 812 into non-quantized spatial domain image information 814 based on the quantization factor 430. In step 910, the motion compensation module 806 adds the pre-processed image information 828 to the pre-processed image information 828 based on the motion vector 414 to provide the image information 156 for the color conversion module 114.

As shown in figure 10 of the drawings,

1000 define typical steps generally performed by the response time compensation and compression system 104. The process begins at step 1002, where the input module 102 receives the RGB image information 126. In step 1004, the color conversion module 112 applies a YCrBr transform, known in the art, to convert the color information 134 based on the RGB information 126 into YCrCb information 136. In step 1006, the motion vector module 422 determines the optimal motion vector 414 based on the plurality of YCrBr information 136 based complex values 426 and the previous image information 416. In step 1008, the quantization factor generation module 402 determines the quantization factor information 430 based on the complexity value 418 (e.g., the lowest value of the plurality of complexity values 426), the target number of bits 147, and the number of bit usages 432 that pack the compressed information 138 into a bitstream.

In step 1010, the transform quantization module 404 transforms the processed image information 428 in the spatial domain into quantized frequency domain information 432 based on the quantization factor information 430. In step 1012, the entropy module 410 variable-length codes the quantized frequency-domain information 432 based on the entropy information 148 to provide variable-length coded information 438. In step 1014, the packing module 412 packs the variable length coding information 438, the quantization factor information 430, and the motion vector information 414 into a bitstream of compressed image information 138. As discussed previously, the quantization factor information 430 and the motion vector information 414 can be variable length coded using the entropy information 148 before being packed into a bitstream of compressed image information 138. In step 1016, the compressed image information 138 is stored in the memory 122 as a previous frame 140(N-1) and/or a previous frame 142 (N-2).

In step 1016, the unpacking module 800 of the decompression module 118 extracts the motion vector information 414, the quantization factor information 430, and the compressed image information 810 from the previously compressed information 152. In step 1018, the inverse entropy module 802 variable-length decodes the compressed image information 810 based on the entropy information 154 to provide decoded quantized image information 812. In step 1020, the inverse transform quantization module 804 converts the decoded quantized image information 812 into non-quantized spatial domain image information 814.

In step 1022, the motion compensation module 806 provides the pre-processed image information 808 based on the motion vector information 414 and the non-quantized spatial domain image information 814. In step 1024, the color conversion module 114 converts the decompressed pre-image information 156, which is the sum of the pre-processed image information 828 and the unquantized spatial domain image information 814, to pre-image RGB information 158 using an inverse YCrCb conversion technique. In step 1026, the display element RTC module 120 determines the display element RTC information 160 based on the front image RGB information 158 and the current image information 134. The process ends at step 1028.

As described above, in addition to the above advantages, when the performance of the display is improved using the response time compensation, the previous frame of the image information is compressed, which allows the information stored in the memory to be minimized. Furthermore, by selectively turning off and/or bypassing compression modules, decompression modules, and/or display element response time compensation modules that are not needed due to the display mode of the display, power consumption may be minimized. Thus, the quantization factor generation module and method provide quantization factors for packing image information into a compressed bitstream, which can minimize information stored in memory when response time compensation is used to improve the performance of a display. Further, the system is able to maintain a static display image when the upstream components are off, and those skilled in the art will appreciate other advantages of the invention.

The foregoing discloses only some specific embodiments of the present invention and is not to be construed as limiting the invention to the disclosed embodiments. Any modification, variation, change, substitution and equivalent arrangement known to those skilled in the art can be adopted without departing from the scope of the present disclosure, the specification and the claims.

Claims (14)

1. An apparatus for response time compensation, the apparatus comprising:

a compression module for compressing a current frame to generate a compressed previous frame of image information;

a decompression module for decompressing a pre-compressed frame of the image information to generate a pre-decompressed frame of image information;

a display unit response time compensation module for providing display unit response time compensation information for the display based on the current frame and the decompressed previous frame; and

a bypass control module for causing the current frame information to selectively bypass at least one of the compression module, the decompression module, and the display unit response time compensation module based on display mode information, wherein,

the compression module generates a pre-compressed frame of the image information based on uncompressed image information and a quantization factor.

2. The apparatus of claim 1, wherein the display mode information comprises at least one of a dynamic image mode, a static image mode, a lost input information mode, and a low power consumption mode.

3. The apparatus of claim 2, wherein the display unit response time compensation module is configured to output the decompressed previous frame when the display mode information is the lost input information mode.

4. The apparatus of claim 1, wherein the bypass control module selectively turns off at least one of the compression module, the decompression module, and the display unit response time compensation module based on the display mode information.

5. A method for compensating for display image response time, the method comprising:

selectively compressing a current frame based on display mode information to generate a compressed previous frame of image information and saving the compressed previous frame of image information;

selectively decompressing a pre-compressed frame of the image information based on the display mode information to generate a pre-decompressed frame of image information; and

selectively providing display unit response time compensation information for a display based on at least one of the current frame and the decompressed previous frame based on the display mode information, wherein,

a pre-compression frame of the image information is generated based on uncompressed image information and a quantization factor.

6. An apparatus for response time compensation, the apparatus comprising:

a compression module, comprising:

a quantization factor module for providing a quantization factor based on the complex value of the spatial domain image;

a transform quantization module for transforming the spatial domain image into quantized frequency domain image information based on the quantization factor;

an entropy module for variable length coding the quantized frequency domain information to generate compressed image information; and

a display unit response time compensation module for providing display unit response time compensation information based on the compressed image information.

7. A method of displaying an image, the method comprising:

generating display element response time compensation information for the display based on the compressed image information,

the step of generating the compressed image information includes:

providing a quantization factor based on the complex value of the spatial domain image information;

converting the spatial domain image information into quantized frequency domain image information based on the quantization factor;

variable-length coding the quantized frequency domain information generates the compressed image information.

8. The method of claim 7, wherein the step of generating the compressed image information further comprises:

determining a plurality of complexity values based on the current image information and the previous image information;

determining an expected complexity value based on a lowest value of the plurality of complexity values;

determining a desired motion vector based on a lowest value of the plurality of complexity values, wherein the desired complexity value and the desired motion vector are used to compress the current picture information into a compressed bitstream.

9. An apparatus for response time compensation, the apparatus comprising: a compression module, comprising:

a quantization factor generation module for providing a quantization factor based on a complex value of current image information;

a transform quantization module for transforming the at least one spatial domain component block into at least one quantized frequency domain component block;

an entropy module for providing at least one block of encoded information by variable length coding at least one block of quantized frequency domain components;

a packing module for packing the at least one encoded information block into a bitstream based on the quantization factor,

wherein the quantization control module is configured to adjust the quantization factor based on a number of bits in the bitstream; a memory operatively connected to the compression module to store compression information as a pre-compression frame;

a decompression module: a memory operably connected to decompress the compressed previous frame of image information to produce a decompressed previous frame;

and the display unit response time compensation module is used for providing display unit response time compensation information for the display based on the current frame and the decompressed previous frame.

10. The apparatus for response time compensation of claim 9, wherein the compression module further comprises:

a plurality of complexity modules for determining a plurality of complexity values based on the current image information and the previous image information; and

a motion vector module to determine a desired complexity value based on a lowest value of the plurality of complexity values and a desired motion vector based on the lowest value of the plurality of complexity values, wherein the desired complexity value and the desired motion vector are used to compress the current picture information into a compressed bitstream.

11. A quantization factor generation apparatus, characterized in that the apparatus comprises:

a control module for providing error control information based on a target number of bits and a target number of actual bits required to pack at least one compressed block of image information; and

an action module for providing a quantization factor based on the error control information and the complexity value of the at least one compressed block of image information, wherein the quantization factor is for packing the at least one compressed block of image information into a bitstream comprising the target number of bits for providing display unit response time compensation information as compressed image information for a display.

12. A method of quantizing factor generation, the method comprising:

providing error control information based on a target number of bits and an actual number of bits required to pack at least one compressed block of image information;

providing a quantization factor based on the error control information and the complexity value of the at least one compressed block of image information, wherein the quantization factor is used to pack the at least one compressed block of image information into a bitstream that compresses the target number of bits, the bitstream being used to provide display unit response time compensation information for a display as compressed image information.

13. An apparatus for response time compensation, the apparatus comprising:

a compression module for providing compressed image information based on uncompressed image information and a quantization factor;

a display unit response time compensation module for providing display unit response time compensation information based on the compressed image information; and

a quantization factor generation module for providing the quantization factor based on a target number of bits required to pack the uncompressed image information into a bitstream of compressed image information, an actual number of bits required to pack the uncompressed image into the bitstream, and a complexity value of at least one block of compressed image information, and error information based on a difference between the target number of bits and the actual number of bits.

14. A method for response time compensation, the method comprising:

providing compressed image information based on the uncompressed image information and the quantization factor;

providing display unit response time compensation information based on the compressed image information; and

the quantization factor is provided based on a target number of bits required to pack the uncompressed image information into a bitstream of compressed image information, an actual number of bits required to pack the uncompressed image into the bitstream, and a complexity value of at least one block of compressed image information, and error information based on a difference between the target number of bits and the actual number of bits.