JP2002536678A - Compression of image data associated with a two-dimensional array of pixel subcomponents - Google Patents

Abstract

LCD Display device (320) with increased horizontal and vertical resolution. The horizontal resolution is increased by mapping spatially different sets of one or more samples to individual pixel sub-components (302, 304, 306). The vertical resolution is increased by increasing the number of pixel sub-component density in the vertical dimension. Image data compression is performed by controlling sets of vertically adjacent pixels (C1, R1) using red, green, and blue luminous intensity values and a bias value of the pixel sub-components (302, 304, 306, 312, 314, 316).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] Background of the Invention 1. FIELD OF THE INVENTION The present invention relates to a method and apparatus for displaying an image, and more particularly, to efficiently providing control signals to a display device by increasing the perceived resolution of the displayed image and compressing the image data. Method and apparatus for enabling transmission.

[0002] 2. Prior art color display devices have become the primary display device of choice for most computer users. Color display on a monitor is usually performed by operating a display device.
It does so by emitting light, typically a combination of red, green and blue light, so that one or more colors are perceived by a human viewer.

In cathode ray tube (CRT) display devices, the different colors of light are produced by phosphor coatings, which are applied in a row in dots on a CRT screen. Can be. Each different phosphor coating is typically used to produce each of the red, green and blue colors, thereby producing a repeating pattern of phosphor dots. These phosphor dots produce red, green and blue colors when excited by an electron beam.

[0004] The term "pixel" is commonly used to refer to a single spot, eg, a spot in a square grid of thousands of such spots. In many computer applications as well as other types of applications,
It is assumed that each pixel corresponds to one square part of the display screen. The pixels are used individually by a computer to form an image on a display device. Single 3 of red, green and blue phosphor dots
For color CRTs that cannot address a triad, the smallest possible pixel size depends on the focus, alignment, and bandwidth of the electron gun used to excite the phosphor. Light emitted from one or more of the triplets of red, green, and blue phosphor dots in various known configurations for CRT displays mix with each other and at a distance,
Emits a single color light source representing a pixel.

Liquid crystal displays (LCDs) and other flat panel displays
Devices are commonly used in place of CRTs in portable computing devices. This is because flat panel displays are easier to make smaller and lighter than CRTs. In addition, flat panel displays generally consume less power than comparable CRT displays, making them more suitable for battery powered applications. As the quality of flat panel color display devices improves and their cost decreases, flat panel displays will continue to replace CRT displays in desktop applications. Therefore,
Flat panel displays, especially LCDs, are becoming even more common.

[0006] A color LCD display is an illustration of a display device that represents each pixel of an image to be displayed using a number of individually addressable and controllable elements (referred to herein as "pixel subcomponents"). is there. In many known LCD displays, each pixel is a single square element and contains non-square red, green, and blue (RGB) pixel subcomponents. The RGB pixel subcomponents combine with each other to form a square pixel.

FIG. 1 shows a portion of one known LCD device 100. The illustrated LCD device 100 includes four columns (C1-C4) and three rows (R1-R3) of pixels, each of which is a separate red pixel subcomponent 102;
It has a green pixel subcomponent 104 and a blue pixel subcomponent 106. These three pixel subcomponents 102,1
Each of 04 and 106 has a height three times their width. These 3: 1
RGB pixel sub-components 102,1 as a result of the aspect ratio of
04, 106 generate one pixel of a square. The RGB pixel sub-components 102, 104, 106 are arranged to form a stripe along the LCD device. RGB stripes typically run in one direction over the entire length of the display. Common LCD devices used for computer applications are wider than tall and have RG
B stripes often run in the vertical direction. For convenience, the invention will be described primarily in the context of LCD devices with vertical stripes, although the principles of the invention also apply to display devices with other pixel sub-component configurations. Things.

In a color display, the corresponding pixel subcomponent 1
By varying the intensity of the red, green, and blue emitted light generated by 02, 104, and 106, almost any desired color pixel appearance can be generated. Emitting no light from the pixel sub-components 102, 104, 106 produces black pixels, while emitting all three colors at 100% intensity produces white pixels.

While conventional displays have been found to be satisfactory for many applications, there is a need for increased resolution. flat panel·
The resolution of the display device is much lower than the resolution achievable by the print media, but it does not support the small text size, high-quality Latin-based characters or similar alphanumeric characters commonly used for reading. It is difficult to display. The problem of low resolution is even greater when displaying complex scripting languages, such as Japanese, Chinese, Korean, and Indian languages. Ideographic languages such as Japanese use a large number of kanji or other characters,
Often heavily relies on vertical resolution as much as horizontal resolution.

[0010] The most complex Kanji characters have nine horizontal lines, and therefore require 17 pixels to display these lines as well as the space between these lines. 10
At the current display resolution of 0 dots / inch, about 14 point type (
With font sizes smaller than one inch (14/72), full rendering cannot be achieved. At 100 dots per inch, the display device does not have enough dots to render complex kanji characters in a text size suitable for readability.

[0011] Japanese books are generally printed in 9, 10, and 11 point types, similar to those used in Western books. This is the desired size for reading based on human physiology. Manga comic books, which are quite common in Japan, use even smaller type sizes. To complicate matters further, the small kana characters used to show Japanese less common reading of kanji characters are usually displayed using a three or four point type. Representing these sized characters on a computer screen, especially an LCD, presents a challenge.

One known technique for dealing with the inability of screen pixels to represent full strokes of a complex character is to use a small sized hand-tuned bitmap. It is. However, these hand-tuned bitmaps, given the resolution of a conventional display,
At best, it is a rough representation of characters that cannot be drawn accurately at the desired display size. In such an implementation, certain strokes of the true character outline must be merged together or eliminated altogether.
Determining which strokes can be edited in such a way requires extensive knowledge of that particular language, and can require considerable time and effort. For example, it is not uncommon for a single typeface to take as long as two years to create in this manner, which in some languages is 7
There are as many as 000 characters. Also, embedded bitmap fonts have the disadvantage of requiring a large amount of memory to store. Because of these limitations, Japanese operating systems often ship with only a few typefaces supported. In fact, Microsoft Corp. for personal computers for Japanese
n of Redmond, Washington) currently includes only two Japanese typefaces, MS Gothic and MS Mincho. Kanji characters are one type that is particularly difficult to render on LCD display devices, but the same low resolution problem applies to displaying any character.

In view of the foregoing, there is a need for an improved technique for displaying images on a display device. It is desirable for any such technique to increase resolution in at least one dimension and more preferably in two dimensions (ie, horizontal and vertical dimensions). Also, from a manufacturing perspective, use existing display technologies and manufacturing equipment to manufacture at least some new display devices, thereby avoiding the costs associated with developing or acquiring new display device manufacturing equipment. It is also desirable.

[0014] Abstract The present invention relates to a method and system for improving the resolution of the display image in the horizontal dimension and vertical dimension of the other flat panel display device having a LCD or separately controllable pixel sub-components About. One factor responsible for at least some portion of this improved resolution is to treat separately controllable pixel sub-components as individual intensity sources, rather than entire pixels. Each pixel subcomponent represents a spatially different portion of the image. To achieve such a result, one or more samples of a spatially distinct set of image data are mapped to individual pixel sub-components rather than entire pixels.

[0015] Such displaced sampling is responsible for increasing the resolution of the display device in a direction perpendicular to the stripes of the display device. Increased resolution in a direction orthogonal to it (ie, in a direction parallel to the stripe) is achieved by increasing the pixel subcomponent density beyond that of conventional display devices. For example, each region of a display device that typically consists of a single pixel with three pixel sub-components may include two or three full pixels, each of which includes three pixel sub-components. To be configured. The pixel subcomponent has a height 1.5 times greater than its width when doubling the pixel subcomponent density, and a square when doubling the density. Become. This pixel subcomponent density can also be increased by other factors, except that a factor of two or three is that the height dimension is not less than the width dimension, and that existing pixel subcomponent manufacturing techniques Can be easily adapted to construct such a display device.

A display device having the above pixel and pixel subcomponent configuration can display an image with improved resolution in both the vertical and horizontal dimensions as compared to a conventional rendering process. This two-dimensional improvement in resolution is particularly advantageous for displaying complex characters, such as Chinese characters, where character features with fine detail rely heavily in both the horizontal and vertical dimensions.

Many existing computers have the ability to transmit light intensity values in a control signal to a display device at a rate large enough to support the increased pixel subcomponent density of the display devices disclosed herein. Does not have. In order to use the available bandwidth of such computers,
The image data and image rendering process of the present invention also extends to image data compression techniques.

This image data compression process is adapted to encode a light intensity value to be applied to a set of vertically adjacent pixels called one control element of the display device. This control element includes a set of two vertically adjacent pixels when doubling the pixel subcomponent density and three vertically adjacent pixels when doubling the pixel subcomponent density. A set of pixels, whereby the control elements occupy a substantially square portion of the display device.

The light intensity values applied to the pixel sub-components in one control element encode, for example, a data structure 8, 16 or 24 bits long. This data structure includes a red light intensity value, a green light intensity value, a blue light intensity value, and a bias value.
These red, green and blue light intensity values correspond to the overall or average brightness to be generated in the pixel subcomponent of the control element. The bias value indicates the relative brightness between multiple pixels in the control element. For example, if the control element includes two vertically adjacent pixels, the bias value may determine whether the luminance should be biased to the upper pixel, the lower pixel,
Or indicate whether to distribute evenly.

The data compression technique of the present invention allows control signals to be transmitted to a display device at substantially the same rate that would be encountered without increasing the pixel subcomponent density. In other words, if a particular display system operating on a computer transmits 16 bits of data per square pixel in the absence of the increased pixel subcomponent density, the display with the increased pixel subcomponent density -The compressed control signal for the device can also use 16 bits of data per control element (i.e. the square area of the display device). Of course, the cost of this data compression is generally some loss of resolution compared to the resolution that would be obtained if each pixel were controlled independently without data compression.

The present invention also extends to a display device further adapted to reduce the color artifacts that can be generated from treating each pixel subcomponent as a separate luminance source. In one embodiment, the positions of the red and blue pixel subcomponents within one pixel are swapped in every other adjacent row. This pixel subcomponent configuration separates the vertical stripes of the same color red and blue pixel subcomponents that are present in many conventional display devices, thereby resulting in color fringing effects that may be experienced. To reduce. In other implementations, successive rows of pixels have red, green, and blue pixel sub-components offset by one-third or two-thirds of the width of a full pixel, such that the stripes are the same. Do not form with color pixel sub-components, but instead form from alternating red, green, and blue pixel sub-components.

[0022] Other advantages of the present invention will be set forth in the description that follows, and in part will be apparent from the description, or may be learned by the practice of the invention. These advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the invention will become more fully apparent from the following description and appended claims, or may be learned from the practice of the invention as set forth hereinafter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS For a method to obtain the above and other advantages of the present invention, a more particular description of the invention outlined above is set forth in the accompanying drawings. This is performed with reference to a specific embodiment. It should be noted that these drawings merely illustrate representative embodiments of the present invention, and thus are not to be considered as limiting the scope thereof, and are not to be construed as limiting the present invention. Describe in increasing gender and detail.

The present invention is directed to a system and method for enhancing the resolution of an image displayed on an LCD or other display device having pixels that include individually controllable pixel subcomponents. Here, the display
The device has vertical stripes and a significant portion of its enhanced resolution in the horizontal dimension performs displacement sampling on the image data and maps the displacement samples to individual pixel locations instead of mapping the samples to all pixels. It is assumed that it is realized by mapping to a subcomponent. Improved resolution in the vertical dimension is achieved by increasing the pixel subcomponent density in the vertical dimension. To accommodate this increased number of pixel subcomponents, the present invention also provides an image
It also relates to data compression techniques, and thereby controls sets of vertically adjacent pixels using red, green, and blue luminosity and bias values. The red, green, and blue intensity values control the overall luminance from the set of red, green, and blue pixel subcomponents, while the bias value should shift the luminance to a particular pixel in the pixel set. Whether or not and how much to shift.

I. Illustrative Computing and Hardware Environment Embodiments of the present invention may be implemented on special purpose or general purpose computers, including various computer hardware described in detail below. Embodiments within the scope of the present invention also include computer-readable media carrying or storing computer-executable instructions or data structures. Such computer-readable media can be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer readable media includes RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or a desired program The code means may include any other medium that can carry or store computer-executable instructions or data structures in a form that can be accessed by a general purpose or special purpose computer.

When information is transferred or provided to a computer over a network or other communication connection (either hardwired, wireless, or a combination of hardwired and wireless), the computer can read this connection computer-readable Considered appropriately as a medium. Thus, any such a connection may be properly termed a computer-readable medium. Combinations of the above should also be included within the scope of computer readable media. Computer-executable instructions comprise, for example, instructions and data which cause a general purpose computer, special purpose computer or special purpose processing device to perform a certain function or group of functions.

FIG. 2 and the following discussion are intended to provide a brief, general description of one suitable computing environment in which the invention may be implemented. Although not required, the invention will be described in the general context of computer-executable instructions, such as program modules, being executed by computers in a networked environment. Generally, program modules are routines, programs,
It includes objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types. Computer-executable instructions, associated data structures, and program modules represent program code means for performing the steps of the methods disclosed herein.
The particular sequence of such executable instructions or associated data structures is the corresponding act for implementing the functionality described in such a step.
Represents an example.

As will be appreciated by those skilled in the art, the invention relates to personal computers, handheld devices, multiprocessor systems, microprocessor-based or programmable consumer electronics, network PCs, minicomputers, It can also be implemented in a network computing environment with many types of computer system configurations, including frame computers and the like. The present invention also relates to a distributed computing environment in which tasks are performed by local and remote processing devices that are linked through a communications network (by a hardwired link, a wireless link, or a combination of hardwired or wireless links). Is also feasible. In a distributed computing environment, local and / or remote memory storage devices store programs,
Modules can be placed. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.

Referring to FIG. 2, an exemplary system implementing the present invention comprises a general-purpose computing device in the form of a conventional computer 20, which comprises a processing unit 21, a system
It includes a memory 22, and a system bus 23 that couples various system components including the system memory 22 to the processing unit 21. System bus 23 may be any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. System memory is read-only
A memory (ROM) 24 and a random access memory (RAM) 25 are included. A basic input / output system 26 (BIOS), which contains the basic routines that assist in transferring information between elements within the computer 20 as it is running, can be stored in the ROM 24.

Further, the computer 20 includes a hard disk drive 27 that reads and writes a magnetic hard disk 39, a magnetic disk drive 28 that reads and writes a removable magnetic disk 29, and a CD-ROM, a CD-R
, A CD-RW, or other optical media. Magnetic hard
The disk drive 27, the magnetic disk drive 28, and the optical disk drive 30 are connected to a system bus via a hard disk drive interface 32, a magnetic disk drive interface 33, and an optical disk drive interface 34, respectively. 23. The drives and their associated storage media provide nonvolatile storage of machine-readable instructions, data structures, program modules and other data for the computer 20. One example of the environment described herein employs a magnetic hard disk 39, a removable magnetic disk 29, and a removable optical disk 31, although those skilled in the art will recognize magnetic cassettes, flash memory cards, digital
Other types of storage media may be used, such as video disks, Bernoulli cartridges, RAM, ROM, and the like.

The program code means comprising one or more program modules, including an operating system 35, one or more application programs 36, other program modules 37, and program data 38,
It can be stored on the hard disk 39, the magnetic disk 29, the optical disk 31, the ROM 24 or the RAM 25. The user may have, for example, a keyboard 40 and a pointing device 42, or a microphone, joystick,
Other input devices such as game pads, satellite dishes, scanners, etc.
(Not shown) allows commands and information to be input to computer 20. Often, these and other input devices are connected to system bus 2
3 through a serial port interface 46 coupled to the processing unit 21. Alternatively, the input devices may be connected by other interfaces, such as a parallel port, a game port, or a universal serial bus (USB). Also, for example, a monitor 47 or other display device can be connected to the system bus 23 via an interface such as a video adapter 48. In addition to the monitor, the computer 20 can typically also include other peripheral output devices (not shown), such as, for example, speakers and printers.

Computer 20 is also operable in a networked environment using logical connections to one or more remote computers, such as remote computers 49a, 49b. The remote computers 49a, 49b can be another personal computer, server, router, network PC, peer device or other common network node, and are further described above in connection with computer 20. Many or all of the elements may be included.
However, FIG. 2 shows only the memory storage devices 50a and 50b and the application programs 36a and 36b related thereto. The logical connections shown in FIG. 2 include a local area network (LAN) 51 and a wide area network (WAN) 52. Such a networking environment is
It is common in office-wide, enterprise-wide computer networks, intranets and the Internet.

When used in a LAN networking environment, the computer 20 connects to a local network 51 via a network interface or adapter 53. When used in a WAN networking environment, the computer 20 may include a modem 54, a wireless link, or a wide area network 5
2 may include other means of establishing communication. The modem 54 may be internal or external and may be connected to the system bus 23 via the serial port interface 46. In one networked environment, a computer 20
May be stored on a remote memory storage device. As will be appreciated, the network connections shown are exemplary and other means of establishing a communications link between the computers may be used.

II. LCD Display Devices computer display device having an increased pixel sub-component density is a two-dimensional device. Display devices are typically oriented in an upright format for convenience, and the first and second dimensions of the display device are commonly referred to as a vertical (y) dimension and a horizontal (x) dimension. By rotating this physical display device, the horizontal and vertical dimensions can be swapped. For purposes of explanation, the method and apparatus of the present invention include:
The vertical dimension and the horizontal dimension will be described. But, as should be understood,
By rotating the exemplary display device described, a vertical resolution improvement in the horizontal direction and a horizontal resolution improvement in the vertical direction can be achieved.

As described above, pixel elements typically include red, green, and blue pixel subcomponents. The light intensity of each pixel subcomponent can also be controlled separately by selecting a light intensity control value associated with that particular pixel subcomponent. In most known devices, each R, G, B pixel subcomponent is rectangular in shape and has three times the height than the width. The three rectangular pixel sub-components form one square pixel.

According to one embodiment of the present invention, the R, G, B luminosity values represent different parts of the image by being controlled independently. This provides up to a three-fold improvement in horizontal spatial resolution over that of conventional rendering techniques that use whole pixels to represent a single portion of the image.

Unfortunately, however, if the R, G, B elements are arranged in vertical stripes, as in the conventional LCD device shown in FIG.
Treating sub-components as separate light intensity value sources may cause some color distortion. For example, unwanted red and / or green vertical stripes or fringes may be visible in the displayed image. In one embodiment of the present invention, in order to reduce the visibility of color artifacts introduced by treating the pixel subcomponent as an independent luminance source, instead of this general RGB stripe display pattern, As shown in FIG. 3, a pattern is used in which the positions of the red and blue pixel subcomponents in every other row are swapped. Row R1 of display device 200
Contains a series of pixel sub-components with an (R, G, B, R, G, B ...) pattern. In contrast, row R2 contains (B, G, R, B, G, R
…) Includes a series of pixel sub-components with a pattern. In other words, vertically adjacent pixel sub-components 202 and 21
2 has different colors (red and blue), vertically adjacent pixel subcomponents 206 and 214 have the same green color, and vertically adjacent pixel subcomponents 208 and 216 Have different colors (blue and red).

Such a pixel sub-component configuration can reduce the effect of color artifacts by removing continuous red and blue vertical pixel sub-component stripes. It is these continuous vertical stripes that can create distracting red and blue fringing effects in the image. Instead of having vertical stripes of red and blue pixel subcomponents of the same color, LCD device 200 has vertical stripes of alternating red and blue pixel subcomponents.

The above technique of treating pixel sub-components as independent luminance sources can result in a significant increase in spatial resolution in a dimension perpendicular to the direction of the stripe. When this display device has vertical stripes,
This method of increasing image resolution is particularly useful for rendering Latin-based characters or other characters that rely more heavily on vertical character features than on horizontal character features. However, as noted above, kanji characters are generally as strongly dependent on horizontal character features as they are on vertical features. Therefore, in order to improve the readability of kanji characters, it is important to improve not only the vertical resolution but also the horizontal resolution.

In various embodiments of the present invention, the resolution is increased in the vertical dimension by increasing the number of pixel subcomponents in this dimension. For example, the number of pixel sub-components per unit distance in a direction parallel to the stripe is two times less than the conventional display device shown in FIG.
Can be doubled. One example of such a display device is shown in FIGS. 4A and 4B. LCD display device 320 shown in FIG. 4B
Section includes rows R1-R3 and columns C1-C4. Rows R1-R3 represent scan lines of display device 320 oriented vertically for vertical striping. In contrast, display devices with horizontal striping have vertical scan lines. Each area of the LCD device 320 that would correspond to a single full pixel with three pixel sub-components in a conventional display device represents two pixels, encompassing a total of six pixel sub-components . For example, FIG. 4A shows one such area 300 of a display device 320, which is identified by reference numeral 302.
, 304, 306, 312, 314 and 316, respectively, including separately controllable pixel subcomponents R1, G1, B1, R2, G2, B2.

The pixel and pixel subcomponent configuration of FIGS. 4A and 4B results in a pixel subcomponent that is approximately 1.5 times as high as its width. In other words, the aspect ratio of the pixel subcomponent is 1.5: 1. It should be noted that the aspect ratio can describe the size and relative positioning of the pixel subcomponents, regardless of whether the display device has vertical or horizontal stripes. This reduced aspect ratio of the pixel sub-components of FIGS. 4A and 4B has the effect of increasing the vertical resolution. This apparent factor in increasing resolution, as explained in more detail below,
It relies heavily on how the pixel sub-components 302, 304, 306, 312, 314 are controlled. Displaying characters with increased vertical resolution and increased horizontal resolution when the pixel and pixel subcomponent configurations of FIGS. 4A and 4B are combined with the techniques described above to increase the perceived resolution in the horizontal dimension Can be.

FIGS. 4C and 4D show a portion of an LCD device 350 whose pixel subcomponents are approximately 1.5 times wider than in the example of FIGS. 4A and 4B. It has a high pixel sub-component and, in contrast, is combined with the swapping of the positions of the red and green pixel sub-components in every other row described with reference to FIG. 4D display device 3 corresponding to a single full pixel in a conventional LCD device
Each of the 50 regions represents two pixels including a total of six pixel subcomponents. For example, the area 330 in FIG.
It includes pixel sub-components R1, G1, B1, R2, G2, B2 indicated at 336, 342, 344 and 346, respectively. 4C and 4D
This embodiment of not only can produce increased resolution in the vertical and horizontal directions, but can also reduce some of the color artifacts that would otherwise be encountered.

In another embodiment, the resolution is increased by doubling the number of pixel subcomponents in the vertical direction. For example, in FIG. 5B, each region of the display device 450 corresponding to a single full pixel in a conventional LCD device represents three pixels that encompass a total of nine pixel sub-components. For example, the area 400 in FIG.
, 404, 406, 408, 410, 412, 414, 416 and 418, respectively, the pixel subcomponents R1, G1, B1, R2, G2, B
2, R3, G3, and B3. The pixel and pixel subcomponent configurations of FIGS. 5A and 5B result in pixel subcomponents having a square or near square or near 1: 1 aspect ratio.

While doubling or tripling the resolution in the vertical dimension can be implemented using existing display device manufacturing equipment, it is possible to reduce the pixel size more than is already seen in the horizontal dimension. This is because gradation between subcomponents is not required.

As described above, pixels in the direction of striping of the display device
Specific examples have been presented in which the number of subcomponents is increased by a factor of two or three.
To increase this pixel subcomponent by a factor of two and three,
For example, there is a certain advantage that a display device can maintain a generally square area and at least a pixel sub-component height that is at least as large as its width, which is an advantage of previously known manufacturing techniques. Be able to adapt these display devices to build. However, the present invention can also be extended to increase the pixel subcomponent density by other factors, to increase the resolution in the direction parallel to the stripe.

Each set or triple of RGB pixel sub-components generated by increasing the number of pixel sub-components in a parallel direction with striping can be treated as one separate pixel. Such a treatment would result in non-square pixels that are half as high as wide when the pixel subcomponent density is increased by a factor of two. To make full use of all these pixels, the display software must
A signal will be generated and transmitted that contains twice as much light intensity value associated with the pixel subcomponent than would otherwise be required if the subcomponent density was not increased by a factor of two. Similarly, when the pixel subcomponent density is increased by a factor of three, the number of light intensity values may be different if the pixel subcomponents are completely and independently used to represent different parts of the image data. Will be tripled.

III. Image Data Compression The large number of light intensity values to be transmitted in control signals for display devices such as those shown in FIGS. 4A-5B present bandwidth problems in certain systems. That is, some systems may not have the ability to generate and transmit such multiple independent light intensity values during the time available for each update of the display device. In addition, as mentioned above, many existing image processing applications assume that the pixels are square. There are some inefficiencies or complications associated with using non-square pixels in such applications.

To compensate for the limited bandwidth capabilities of many existing computer systems,
Embodiments of the present invention relate to compressing light intensity values associated with pixel subcomponents of a display device having increased pixel subcomponent density. This data compression sacrifices some resolution in exchange for reducing the data transmission requirements for rendering the image.

In a system capable of processing and transmitting the required number of video control signals twice or three times in the absence of increased pixel sub-component density, each set of RGB pixel sub-components Or the triples can be treated as independent pixels without using the data compression techniques described herein. However, when image data compression is beneficial, the pixel sets are grouped together for control purposes.

For example, in FIGS. 4A-4D, where the pixel subcomponent density is doubled in the vertical dimension, two sets of vertically adjacent RGB pixel subcomponents are grouped together to form a pair of adjacent pixels. Form a pixel, which is referred to herein as a "control element". For example, the region 300 in FIG.
A region 400 of A is an example of a control element. In such an embodiment, each pair of pixels occupies a generally square area of the display device, and thus corresponds in size to a single pixel of a conventional display device.
The control element can consist of adjacent pixels, but the control element can generally consist of two or more pixels, whether or not the pixels are adjacent to each other.

For data compression purposes, according to one embodiment of the present invention, the luminance generated by the pixel sub-component in each control element is a single red luminosity value, a single green luminosity value, a single Control using a single blue luminosity value and a bias value. The bias value is
It indicates how the light energy specified by the R, G, B light intensity values is to be distributed or applied differently between the upper and lower pixels of the control element. This bias value indicates, for example, whether the luminance should be evenly distributed between the upper pixel and the lower pixel, or whether the upper pixel or the lower pixel should be weighted by a specified factor.

The opportunity for bias depends on the specified luminosity of each color component. Thus, if different intensity values are assigned to different color components, the bias opportunity will be different for each of the R, G, B components. Medium gray offers a great opportunity for bias since the R, G, B luminosity values are each at their intermediate values. This allows one pixel subcomponent to be a pair of pixels, each with R,
In control elements, including those having G, B pixel sub-components, allow them to be completely turned on, and the corresponding pixel sub-components in the other pixels in this control element are If so, it can be allowed to be completely turned off without affecting the overall energy output.

To optimize the use of the available bandwidth to transmit the light intensity values to the display device, the number of bits contained in the red, green, and blue light intensity values as well as the bias values may affect the perception of color by humans. The choice can be made in view of the relevant empirical observations. In general, most people can perceive green light better than red or blue light. Studies have shown that generally 60% of the perceived total luminous intensity of a light source that outputs red, green, and blue light of the same luminosity is associated with green light. , 30% relate to red light and 10% relate to blue light. For this reason, one tends to be able to distinguish differences in green light intensity values much better than differences in red or blue light intensity values.

In many conventional computer systems, the luminosity of the R, G, B pixel subcomponent is controlled using control signals that include 8, 16, or 24 bits per pixel. A large number of 8 bits are often used in control signals to allow the data used to transmit such signals to be transmitted.
Word data capacity is used efficiently. In conventional systems that use a total of 8 bits to specify the red, green, and blue pixel sub-component luminosity values for a single pixel, typically a 3-bit, green luminosity value is used to specify the red luminosity value. Three bits are assigned to specify the luminosity value and two bits are specified to specify the blue luminosity value. Conventional systems that use a total of 16 bits to specify the intensity values of the red, green, and blue pixel subcomponents typically specify a 5-bit, green intensity value to specify the red intensity value. 6 bits, and 5 bits to specify the blue luminosity value.

To support a very large number of different color displays, many personal
Some conventional computer systems, including computers, use 24 bits to specify the intensity values of the red, green, and blue pixel subcomponents that form a single pixel. In such systems, 8 of the 24 available bits are typically used exclusively to specify the intensity value of each of the red, green, and blue pixel subcomponents.

The bit assignments commonly used to specify the intensity values of the pixel subcomponents in conventional systems are shown in Table 1.

[0057]

[Table 1] By using fewer bits than are commonly used in the example shown in Table 1 to represent the RGB intensity value set and dedicating the unused bits to use as bias values, the increased pixel Display devices with subcomponent densities can be controlled by using control signals that do not require transmitting more data. Of course, there is often some loss of spatial or color resolution in the rendered image at the expense of performing such data compression.

In the method described above, a display device with two pixels in each control element is an 8-bit signal (two bits for the R luminosity value, two bits for the G luminosity value, and two Using the bits for the B luminosity value and 2 bits for the bias value). If 16 bits per control element are available, use 4 bits to specify the red luminosity value;
Use bits to specify the green luminosity value, use 4 bits to specify the blue luminosity value,
You can use bits to specify the bias value. For a 24-bit interface, use 8 bits to specify the red light intensity value, use 8 bits to specify the green light intensity value, use 6 bits to specify the blue light intensity value, and use 2 bits to specify the blue light intensity value. Can be used to specify the bias value.

These ratios are advantageous for reassignment of blue and / or red intensity value control bits for use as bias value bits, but humans may be required to assign different luminance levels to these colors. Is less sensitive to different luminance levels of green. However, alternative assignment of control bits to light intensity and bias values is also possible. For example, another embodiment of the present invention uses three bits to support a wider range of intensity bias values. In yet another embodiment, the use of six bias bits allows independent control of the bias for each pair of red, green, and blue pixel subcomponents. In one 6-bit bias control signal embodiment, each pair of bias bits represents a separate red, green, and blue bias signal.

The two-bit bias value indicates whether a certain bias should be applied and which of the upper or lower RGB set should be responsible for outputting most of the light energy from this pixel element. Can be. For example, in one exemplary embodiment, the bias control signal value 00 indicates that the luminance energy should be evenly distributed between the upper and lower pixels, and the bias control signal value 10 indicates that the luminance energy should be distributed. Indicates that the lower pixel should be biased downward so that the lower pixel outputs more light than the upper pixel, and the bias control signal value 01 biases the luminance energy upward so that the upper pixel has a higher output than the lower pixel. Also indicates that more light should be output.

Although the light intensity control technique of the present invention involves the use of separate R, G, B light intensity values in conjunction with bias values, this technique involves three or more sets of R, G, B light intensity values. Can be used to control pixel elements consisting of values. Such a control method triples the pixel subcomponent density in the vertical dimension so that each RGB pixel subcomponent is square and has a vertical dimension and a horizontal dimension equal to one third of the width of one pixel. It is particularly suitable for advanced applications. In such an embodiment, three vertically adjacent pixels can be grouped together to form a single square control element.

In one such embodiment where each control element includes three sets of RGB pixel sub-components, a 3-bit bias control signal is used. This 3-bit bias signal supports a sufficiently large number of different intensity energy distributions to provide a reasonable use of the available vertical resolution corresponding to three vertically adjacent pixels.

The value of the bias bit can be obtained by sampling the image data so that the vertical distance between vertically adjacent samples is equal to the height of the pixel subcomponent. it can. To select this bias bit, first, two (or three) desired RGB intensity values are averaged in the component direction with respect to each other, and each color is quantized to the appropriate level for the display device. Become This averaging of the RGB light intensity values corresponds to the desired overall brightness for the control element. Next, for each possible bias bit setting, calculate the total brightness generated in the control element and compare it to the averaged desired output for the control element. These control element outputs are 2 × 3 as disclosed in the text.
This is a pattern consisting of an emitter or a 3 × 3 emitter. In one embodiment, the bias bits are chosen to minimize the square of the Euclidean distance between the averaged desired control element output and the actual control element output. Other error metrics may also be used, including those that will become apparent to those skilled in the art from the teachings of the present invention disclosed herein.

In one exemplary embodiment, the result of the resolution enhancement filtering may be quantized as one 8-bit value per control element. In this embodiment, the vertical pixel subcomponent density (and corresponding sampling rate) is increased by a factor of two. Therefore, the two 8-bit filtered RGB values should be converted into one 8-bit signal containing the RGB luminosity value and the bias value. This conversion can be performed via a look-up table, which uses techniques that will be understood by those of skill in the art upon learning the invention disclosed herein. If the look-up table is implemented in software by the operating system, it does not require a large amount of computation. Also, alternatively, the look-up table can be implemented in hardware on the video card.

IV. Character Examples FIGS. 6 and 7 qualitatively illustrate the increased resolution often obtained by displaying images in accordance with the present invention. 6 and 7 are:
Instead of using the data compression technique of the present invention, it can be generated by controlling each pixel independently with a bias value. The characters shown in FIGS. 6 and 7 are provided by way of example, and not limitation.
The result of any particular rendering process depends on many factors, including the size of the pixel subcomponents, the sampling and filtering processes used, and the like.

FIG. 6 shows various expressions of the Japanese kanji “Utsu”, which is
It has a reputation as one of the most complicated kanji. The character in FIG. 7 illustrates how a bitmap that renders only outlines can be rendered with different font sizes and with different pixel subcomponent densities (both vertical and horizontal dimensions). Is shown.

The set of characters 130 is displayed in a 9 point type, which is 88 dpi.
(I.e., 88 pixels / inch full). The character 130a has been rendered using a display device that has a pixel sub-component that is three times higher than its width, in other words, no increase in pixel sub-component density. Character 130b
Are displayed using this same display device, but increase the pixel subcomponent density by a factor of two. Character 13
0c is displayed with the pixel subcomponent density increased by a factor of 3 compared to character 130a.

The set of characters 132 is displayed in a 9-point type, which is 106 dp
It supports LCD display devices with i. Character 132a has been rendered using a display device having a pixel sub-component that is three times higher than wide. Character 132b is displayed using this same display device, except that it increases the pixel subcomponent density by a factor of two. The character 132c is 3 compared to the character 132a.
Are displayed with the pixel sub-component density increased by the following factor.

The set of characters 134 is displayed in a 6-point type, which is 88 dpi.
LCD display devices with. Character 134a has been rendered using a display device having a pixel sub-component that is three times higher than wide. Character 134b is displayed using this same display device, except that it increases the pixel subcomponent density by a factor of two. Character 134c is displayed with an increased pixel subcomponent density by a factor of three compared to character 134a.

The set of characters 136 is displayed in a 6-point type, which is 106 dp
It supports LCD display devices with i. Character 136a has been rendered using a display device having a pixel subcomponent that is three times higher than wide. Character 136b is displayed using this same display device, but increases the pixel subcomponent density by a factor of two. Character 136c is 3 compared to character 136a.
Are displayed with the pixel sub-component density increased by the following factor.

FIG. 7 shows various Chinese characters as seen when displayed in accordance with the present invention. Row 140 contains characters corresponding to an LCD display device having 88 dpi, which increases the conventional pixel subcomponent density by a factor of two. Row 142 contains characters corresponding to an LCD display device having 106 dpi, which increases the conventional pixel subcomponent density by a factor of two. Row 144 shows the pixel subcomponent density increased by a factor of three instead of two.
Represents the character 0. Similarly, row 146 represents the characters of row 142 displaying the conventional pixel subcomponent density increased by a factor of three instead of two.

As can be seen from these examples of rendered characters, the improvement in readability and resolution is dramatic when the characters are complex and rely heavily on horizontal features.

The present invention may be embodied in other specific forms without departing from its spirit and essential characteristics. The described embodiments are to be considered in all respects illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

[Brief description of the drawings]

FIG. 1 shows a portion of a conventional liquid crystal display device.

FIG. 2 illustrates an exemplary system that provides a suitable operating environment for an embodiment of the present invention.

FIG. 3 illustrates a display device in which the positions of the red and blue pixel subcomponents are transposed in every other row of the display device according to one embodiment of the invention. ing.

FIGS. 4A and 4B illustrate a portion of a display device with a doubling of pixel subcomponent density in the vertical dimension according to one embodiment of the present invention. 4C and 4D show that the density of pixel subcomponents in the vertical dimension is doubled while transposing the positions of the red and blue pixel subcomponents in every other row, according to one embodiment of the present invention. 2 shows a portion of a display device.

FIGS. 5A and 5B show a portion of a display device with tripled pixel subcomponent density in the vertical dimension.

FIG. 6 quantitatively illustrates the improvement in readability of various Chinese characters obtained by increasing the pixel subcomponent density in the vertical dimension.

FIG. 7 quantitatively illustrates the improvement in readability of various Chinese characters obtained by increasing the pixel subcomponent density in the vertical dimension.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09G 3/20 650 G09G 3/20 650C 5C080 5/00 H04N 1/387 101 5C082 H04N 1/387 101 9 / 64 F 1/46 G09G 5/00 555G 9/64 H04N 1/46 Z (81) Designated countries EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, I T, LU, MC, NL, PT, SE), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SL, SZ, TZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ TM), AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN , MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, UZ, VN, YU, ZW ( 72) Inventor Hill, William 5401, Lake Langlois Road, Carnation, WA 98401, Washington, USA (72) Inventor Wade, Geraldine, 98052, Washington, USA, Redmond, Northeast Onehand Red Door. Donnines Street 16132 (72) Inventor Hitchcock, Gregory Sea, One Hundred Anne, Woodinville, Washington 98072-9236, United States of America United States 1732 F-term (reference) 5B057 AA01 CA01 CA08 CA12 CA16 CB01 CB08 CB12 CB16 CC02 CD06 CE03 CE16 CH07 DA16 DB02 DB06 DB09 5C006 AA01 AA02 AA22 AC21 AF01 AF11 AF26 AF41 AF47 AF85 BB11 BC16 BF01 BF16 FA41 FA56 5C066 AA03 AA13 BA01 CA06 GA01 GA31 GA32. LA37 MA01 MA04 MA11 MA17 NA04 PA05 5C080 AA10 BB05 CC03 DD22 EE01 EE17 GG02 JJ02 KK02 5C082 AA01 BA02 BA03 BA34 BA35 BB25 BB51 BB53 BD02 CA11 CA32 DA53 DA63 DA86 MM02 MM04 MM07

Claims (32)

[Claims] 1. A computer system having a display device, said display device having a plurality of pixels, each of said pixels having a plurality of pixel sub-components of different colors. A method of displaying an image at an increased resolution on said display device, comprising: acquiring image data representing said image; and controlling a control element of said display device based on said image data. Generating a control signal to be applied, wherein said control element comprises at least two pixels, said control signal comprising: one light intensity value for each of said different colors; To a particular one of the pixels The step of applying the light intensity value and the bias value to the pixel subcomponent, including a bias value indicating whether to apply differently, and to what extent to apply. Displaying the image on a display device. 2. The method of claim 1, wherein said image data representing said image comprises:
A display method comprising: a set of one or more spatially distinct samples mapped to individual pixel subcomponents. 3. The method of claim 1, wherein the control signals to be applied to the control element are: a single red light intensity value, a single green light intensity value, and a single blue light intensity value. And a display method comprising: 4. The method of claim 3, wherein the control signal to be applied to the control element further comprises a single bias value applied to the red, green, and blue luminosity values.
The display method characterized by the above. 5. The method of claim 3, wherein the control signal to be applied to the control element further includes three bias values, each of the three bias values being the red,
A display method, wherein the method is applied to one of green and blue light intensity values. 6. The method of claim 1, wherein the control element occupies a substantially square area of the display device and comprises two adjacent pixels, each of which has three pixel sub-pixels. A display method, comprising a component. 7. The method of claim 1, wherein the control element occupies a substantially square area of the display device and comprises three adjacent pixels, each of which comprises three pixel sub-pixels. A display method, comprising a component. 8. The method of claim 1, wherein the step of generating the control signal comprises the act of generating a data structure for each of at least two pixels included in the control element. Compressing said data structure into said control signal, said act each having a length equal to a specified number of bits and indicating a desired light intensity value for said pixel subcomponent of said particular pixel. And displaying the control signal, wherein the control signal also has a length equal to the designated number of bits. 9. The method of claim 8, wherein the act of compressing the data structure comprises selecting the control signal from a look-up table based on the data structure. 10. A computer program product implementing a method for displaying an image at an increased resolution on a display device in a computer system having a display device, the display device comprising a plurality of pixels. Wherein each of the pixels has a plurality of pixel sub-components of different colors, wherein the computer program product obtains image data representing the image; Generating a control signal to be applied to a control element of said display device, said control element comprising at least two pixels, said control signal comprising one light intensity for each of said different colors. Value and the luminosity value is The above steps, including a bias value indicating whether to apply differently to a particular one of the at least two pixels, and if so, to what extent. Displaying the image on the display device by applying a light intensity value and the bias value; and a computer-readable medium carrying computer-executable instructions for performing: 11. The product of claim 10, wherein the image data representing the image is a spatially distinct one mapped to individual pixel subcomponents.
A computer program product comprising a set of one or more samples. 12. The product according to claim 10, wherein the control element comprises the display device.
Occupying a substantially square area of the device and consisting of two adjacent pixels;
A computer program product, wherein each of the pixels has three pixel sub-components. 13. The product according to claim 10, wherein the control element comprises the display device.
Occupying a substantially square area of the device and consisting of three adjacent pixels;
A computer program product, wherein each of the pixels has three pixel sub-components. 14. The product of claim 10, wherein the step of generating the control signal comprises the act of generating a data structure for each of at least two pixels included in the control element. Compressing said data structure into said control signal, said act each having a length equal to a specified number of bits and indicating a desired light intensity value for said pixel subcomponent of said particular pixel. A computer program product comprising: an act, wherein the control signal also has a length equal to the specified number of bits. 15. The computer program according to claim 14, wherein the act of compressing the data structure comprises selecting the control signal from a look-up table based on the data structure. Product. 16. A computer system for displaying an image at an increased resolution, comprising: a processing unit; and a display device controllable by the processing unit, the computer system comprising a plurality of pixels, each of which is a pixel. A display device having a plurality of separately controllable different color pixel sub-components, each of said plurality of pixels having a shape other than square. 17. The computer system of claim 16, wherein the plurality of separately controllable pixel subcomponents comprises: a red pixel subcomponent;
A green pixel subcomponent and a blue pixel subcomponent, wherein the positions of the red pixel subcomponent and the blue pixel subcomponent are located in every other pixel row on the display device. A computer system, wherein the pixel has been exchanged. 18. The computer system of claim 16, wherein said pixel sub-component has an aspect ratio of approximately 1.5: 1. 19. The computer system according to claim 16, wherein said pixel sub-component has an aspect ratio of approximately 1: 1. 20. The computer system according to claim 16, wherein said display device is a liquid crystal display device.
system. 21. The computer system of claim 16, further comprising computer-readable media carrying computer-executable instructions for displaying an image on the display device, wherein the computer-executable instructions comprise: Obtaining, when executed by the processing unit, image data representing the image; displaying a different portion of the image on each of the pixel sub-components of a particular pixel; Not displaying a single portion of said image over a particular pixel. 22. The computer system of claim 21, wherein the computer-executable instructions, when executed by the processing unit, further apply to a control element of the display device based on the image data. Generating a control signal to be performed, wherein said control element comprises:
Including at least two pixels, wherein the control signal is one light intensity value for each of the different colors and whether the light intensity value is to be applied differently to a particular one of the at least two pixels; Said step comprising applying a bias value indicating how much to apply, if any, to said image component on said display device by applying said light intensity value and said bias value to said pixel subcomponent. Displaying a computer program; and performing a computer program. 23. A display device for displaying an image at an increased resolution, comprising a plurality of pixels, each pixel comprising a plurality of individually controllable pixels.
A pixel sub-component, the pixel sub-component comprising: a red pixel sub-component, a green pixel sub-component, and a blue pixel sub-component; Aligned with the scan line, either in the top row or column, and swapped the positions of the red and blue pixel subcomponents within the pixel in every other scan line A display device. 24. The display device of claim 23, wherein the scan line is a row, and the pixels and the pixel sub-components are arranged on the display device to form green pixels of the same color. A display device, characterized by forming vertical stripes of sub-components and vertical stripes of alternating red and blue pixel sub-components; 25. The display device of claim 23, wherein the scan lines are columns,
The pixels and the pixel sub-components are arranged on the display device such that horizontal stripes of green pixel sub-components of the same color and red and blue pixel sub-components alternate. And a horizontal stripe formed. 26. The display device of claim 23, wherein the pixel sub-component has an aspect ratio of approximately 3: 1 and the pixels have an aspect ratio of approximately 1: 1. A display device. 27. The display device of claim 23, wherein said pixel sub-component has an aspect ratio of approximately 1.5: 1 such that two adjacent pixels have an aspect ratio of approximately 1: 1. A display device occupying one area of the display device having a ratio. 28. The display device of claim 23, wherein the pixel sub-component has an aspect ratio of approximately 1: 1 so that three adjacent pixels have an aspect ratio of approximately 1: 1. One of the display devices having
Display device, which occupies three areas. 29. A computer system having a display device, wherein the display device has a plurality of pixels, each having a plurality of pixel sub-components of different colors.・
A method of displaying an image at an increased resolution on the display device in a system, comprising mapping samples of image data representing the image to individual pixel sub-components of a pixel. , Each of the pixel sub-components of the pixel has a spatially distinct set of one or more of the samples mapped thereto to arrange the pixel sub-components of the plurality of pixels. Forming a stripe of green pixel sub-components of the same color and stripes of alternating red and blue pixel sub-components on the display device; and Each pixel of the pixel Generating, for the component, distinct light intensity values based on the different set of one or more samples mapped to the pixels; and using the distinct light intensity values to display the image on the display device. Displaying, so that each of the pixel sub-components of the pixel, rather than an entire pixel, represents a different portion of the image. Method. 30. The method of claim 29, further comprising, after the step of generating the distinct intensity values for each pixel subcomponent, compressing the distinct intensity values to provide at least two pixels. Generating a control signal used to control a control element of the display device, the control signal comprising at least a single red light intensity value, a single green light intensity value, and a single light intensity value. A blue light intensity value and a bias value indicating whether the light intensity value should be applied differently to a particular one of the at least two pixels, and if so, how much. A display method. 31. The method of claim 30, wherein the pixel sub-component has an aspect ratio of approximately 1.5: 1, such that the control element has a substantially square shape on the display device. A display method occupying an area and comprising two adjacent pixel sub-components. 32. The method according to claim 30, wherein the pixel sub-component has an aspect ratio of approximately 1: 1 so that the control element divides a substantially square area on the display device. Occupy and three adjacent pixels
A display method, comprising a sub-component.