CN1965568A - Method and apparatus for vertically scaling pixel data - Google Patents

Abstract

The invention provides an image processing apparatus that includes a red, green and blue (RGB) color space to luminance color, blue color difference and red color difference (YCbCr) color space converter module for converting a line of pixels from the RGB color space to the YCbCr color space. The line of pixels has a first sampling rate. The image processing apparatus further comprises a chrominance decimator module coupled to the RGB to YCbCr color space converter module. The chrominance decimator module is configured to generate an intermediate representation of the line of pixels having a second sampling rate that is less than the first sampling rate. The amount of data representing the intermediate representation is less than the amount of data representing the line of pixels. The image processing apparatus further comprises a line store memory coupled to the chrominance decimator module. The line store memory is configured to store the intermediate representation. The image processing apparatus further comprises a vertical scaler module coupled to the line store memory. The vertical scaler module is configured to generate a scaled version of the intermediate representation. The image processing apparatus further comprises a chrominance interpolator module coupled to the vertical scaler module. The chrominance interpolator module is configured to convert the scaled version of the intermediate representation having the second sampling rate to a scaled version of the line of pixels having the first sampling rate. The image processing apparatus further comprises a YCbCr to RGB color space converter module coupled to the chrominance interpolator module. The YCbCr to RGB color space converter module is configured to convert the scaled version of the line of pixels from the YCbCr color space to the RGB color space.

Description

Method and device for vertically scaling pixel data

Related Application Cross Reference

This application is a continuation-in-part of co-pending U.S. Patent Application No. 10/825,259, Attorney Docket NVDA/P000715, filed April 15, 2004 by W. Young The application was filed on the 1st and is entitled "MINIMALIST COLOR SPACE CONVERTERS FOR OPTIMIZING IMAGE PROCESSING OPERATIONS" and is incorporated herein by reference.

technical field

Embodiments of the invention generally relate to a method and apparatus for vertically scaling pixel data.

Background technique

Vertical scalers are generally designed to change the number of input lines to a different number of output lines in the output video signal. The vertical scaler scales up or down proportionally. A line usually refers to a video horizontal scanning line. The vertical scaling process can be complicated especially because the input pixel data is in row format. Vertical scaling typically requires comparisons and calculations between many contiguous rows of pixel data. Due to the nature of input pixel data in rasterized format, previous and current rows must be stored until the next row is available. The rows are typically stored in a row store memory consisting of one or more random access memories (RAM). The size of each RAM depends on the number of rows to be stored and the length of each row. Since each line corresponding to the entire width of the image may need to be stored in the line store memory in preparation for vertical scaling, the size of the line store memory can become quite large, making vertical scaling an expensive operation. the process of.

Therefore, there is a need in the art for a more cost-effective method and apparatus for vertically scaling pixel data.

Contents of the invention

It is an object of embodiments of the present invention to reduce the amount of pixel data that needs to be stored in a line store memory associated with vertically scaling pixel data.

Embodiments of the present invention generally relate to an image processing device comprising a red, green and blue (RGB) color space-luminance color, blue difference and red difference (YCbCr) color space converter module, to convert a row of pixels from the RGB color space to the YCbCr color space. The row of pixels has a first sampling rate. The image processing device further includes a chroma decimator module coupled to the RGB-YCbCr color space converter module. The chroma decimator module is configured to generate an intermediate representation of the row of pixels having a second sampling rate lower than the first sampling rate. The amount of data representing the intermediate representation is less than the amount of data representing the row of pixels. The image processing apparatus further includes a line storage memory coupled to the chrominance decimator module. The line store memory is configured to store the intermediate representation. The image processing apparatus further includes a vertical scaler module coupled to the line store memory. The vertical scaler module is configured to generate a scaled version of the intermediate representation.

In one embodiment, the image processing apparatus further includes a chroma interpolator module coupled to the vertical scaler module. The chroma interpolator module is configured to convert the scaled version of the intermediate representation at the second sampling rate into a scaled version of the row of pixels at the first sampling rate Scaled form.

In another embodiment, the image processing device further includes a YCbCr-RGB color space converter module coupled to the chroma interpolator module. The YCbCr-RGB color space converter module is configured to convert the scaled version of the row of pixels to an RGB color space.

In yet another embodiment, the RGB-YCbCr color space converter module determines a luminance color component (Y) of the pixel data in the following manner: a quarter of a red (R) component of the pixel data One is added to one half of a green (G) component of the pixel data and one quarter of a blue (B) component of the pixel data. The RGB-YCbCr color space converter module further determines a green difference component (Cb) of the pixel data by subtracting the luminance color component (Y ) and divide the resulting result by 2. The RGB-YCbCr color space converter module further determines a red difference component (Cr) of the pixel data by subtracting the red (Cr) component of the pixel data from the red (R) component of the pixel data The above-mentioned chromatic difference (Y) and divide the obtained result by 2.

In yet another embodiment, the YCbCr-RGB color space converter module determines the red (R) component of the pixel data by adding the luminance color component (Y) to the pixel data Twice the amount of red difference (Cr). The YCbCr-RGB color space converter module further determines the green (G) component of the pixel by subtracting the red difference component of the pixel data from the brightness color component (Y) of the pixel data (Cr) and blue difference (Cb). The YCbCr-RGB color space converter module further determines the blue (B) component of the pixel data by adding the brightness color component (Y) of the pixel data to the Twice the amount of blue difference (Cb).

Description of drawings

For a greater understanding of the above recited features of the invention, the more detailed description of the invention summarized above may be read by reference to various embodiments, some of which are illustrated in the accompanying drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

Figure 1 illustrates a simplified block diagram of a computer system according to an embodiment of the present invention.

FIG. 2 is a flowchart of a method for converting pixel data from an RGB space to a YCbCr space according to an embodiment of the present invention.

Figure 3A illustrates a logic diagram for determining the luma color component (Y) of pixel data according to one embodiment of the present invention.

Figure 3B illustrates a logic diagram for determining the blue difference component (Cb) of pixel data according to one embodiment of the present invention.

FIG. 3C illustrates a logic diagram for determining a red difference component (Cr) of pixel data according to an embodiment of the present invention.

FIG. 4 illustrates a flowchart of a method for vertically scaling pixel data according to an embodiment of the invention.

5 illustrates a flowchart of a method for converting pixel data from YCbCr space to RGB space according to an embodiment of the present invention.

Figure 6A illustrates a logic diagram for determining the red component (R) of pixel data according to one embodiment of the present invention.

Figure 6B illustrates a logic diagram for determining the green component (G) of pixel data according to one embodiment of the present invention.

Figure 6C illustrates a logic diagram for determining the blue component (B) of pixel data according to one embodiment of the invention.

Detailed ways

FIG. 1 illustrates a simplified block diagram of a computer system 100 according to an embodiment of the invention. Computer system 100 includes a central processing unit (CPU) 102 and a system (main) memory 104 that communicate through a system bus 106 . User input is received from one or more user input devices 108 (eg, keyboard, mouse) coupled to the system bus 106 . Video output is provided on a pixel-based display device 110 (such as a conventional CRT, TV, or LCD-based monitor, projector, etc.) operating under the control of a graphics processing unit (GPU) 112 coupled to bus 106 . Other components, such as one or more storage devices 128 such as a fixed or removable disk drive, compact disk (CD) drive, and/or DVD drive, may also be coupled to the system bus 106 . In one embodiment, computer system 100 operates in a red, green and blue (RGB) color space. Although embodiments of the invention are described herein with reference to computer systems 100 operating in the RGB color space, the invention also encompasses computer systems 100 operating in other color spaces, such as YCbCr.

System memory 104 stores various programs or applications, such as operating system programs for generating pixel data to be processed by GPU 112 . Examples of operating system programs 130 include the graphics device interface (GDI) component of the Microsoft Windows operating system. System memory 104 may further store a graphics driver for enabling communication with GPU 112. The graphics driver may employ one or more standard application programming interfaces (APIs) for communicating with GPU 112, such as Open GL and Microsoft DirectX. By calling appropriate API function calls, the operating system program can instruct the graphics driver to transfer the pixel data to GPU 112 via system bus 106 and invoke various rendering functions of GPU 112. Such pixel data is usually stored and represented in binary form. Data transfer operations may be implemented using conventional DMA (Direct Memory Access) or other operations. In one embodiment, the system memory 104 can store pixel data in RGB color space.

Computer system 100 further includes a local memory or frame buffer 114 in communication with GPU 112. Frame buffer 114 stores pixel data to be read by a scan-out control logic and transmitted to display device 110 for display as an image. In one embodiment, the frame buffer 114 stores pixel data in RGB color space. Although frame buffer 114 is shown as distinct and separate from system memory 104, in some implementations, such as in a Unified Memory Architecture (Unified Memory Architecture), frame buffer 114 and system memory 104 will share the same physical storage device .

GPU 112 includes various components for receiving and processing graphics system commands received over bus 106. GPU 112 includes a memory management unit 120 and a display pipeline 130 . Memory management unit 120 reads pixel data from frame buffer 114 or memory 104 , arranges the pixel data in order, and transfers the pixel data to display pipeline 130 for processing.

The display pipeline 130 is generally used for processing images. Display pipeline 130 may include various processing modules configured to convert pixel data into pixel data suitable for display on a display device. In an embodiment in which computer system 100 operates in an RGB color space, display pipeline 130 may include a module 142 that processes pixel data in a red-green-blue (RGB) color space. Examples of processing modules operating in the RGB color space include brightness control, contrast control, and gamma correction.

In one embodiment, the display pipeline 130 further includes an RGB-YCbCr color space converter module 144 configured to convert pixel data from RGB color space to YCbCr space. A detailed description of the operation of the RGB-YCbCr color space converter module 144 is provided in the following paragraphs with reference to FIGS. 2-3.

Once the pixel data has been converted to the YCbCr color space, the pixel data can be processed in the YCbCr color space. Therefore, the display pipeline 130 may further include a chroma decimator 145 , a vertical scaler 146 and a chroma interpolator 147 . The chroma decimator 145 is configured to downsample the blue difference component (Cb) and the red difference component (Cr) of the pixel data. Chroma decimator 145 may also be referred to as a chroma downsampler. Chroma extractor 145 may also include components generally known to those skilled in the art. For example, chroma decimator 145 may include a low pass filter configured to reduce the bandwidth of the blue difference component (Cb) and the red difference component (Cr) of pixel data. Vertical scaler 146 is configured to vertically scale pixel data stored in line store memory 170 . Vertical scaler 146 may be any vertical scaler generally known to those skilled in the art. The chroma interpolator 147 is configured to increase the sampling rate of the blue difference component (Cb) and the red difference component (Cr) of pixel data. Chroma interpolator 147 may also be referred to as a chroma upsampler. Chroma interpolator 147 may also include components generally known to those skilled in the art. For example, chroma interpolator 147 may include a finite impulse response (FIR) filter. The chroma decimator 145 , vertical scaler 146 and chroma interpolator 147 will be explained in more detail with reference to FIG. 4 in the following paragraphs.

Display pipeline 130 may further include a line store memory 170 in communication with vertical scaler 146 . Line store memory 170 stores pixel data configured to be vertically scaled by vertical scaler 146 . Line store memory 170 may include one or more random access memories (RAM). Although line store memory 170 is shown as distinct and separate from system memory 104 and frame buffer 114 , in some implementations line store memory 170 , system memory 104 and frame buffer 114 may share the same physical storage device.

According to an embodiment of the present invention, the display pipeline 130 further includes a YCbCr-RGB color space converter module 148 configured to convert the pixel data from the YCbCr space to the RGB space. In this way, once the pixel data has been processed in YCbCr space, it can be converted back to RGB space. In one embodiment, once the pixel data has been vertically scaled, the YCbCr-RGB color space converter module 148 converts the pixel data to the RGB space. A detailed description of the operation of the YCbCr-RGB color space converter module 148 will be provided in the following paragraphs with reference to FIGS. 5-6.

Although the display pipeline 130 has been described above in terms of including an RGB-YCbCr color space converter module 144 followed by a YCbCr-RGB color space converter module 148, embodiments of the invention may also contemplate, In the computer system in space, the display pipeline 130 has a YCbCr-RGB color space converter module 148 followed by an RGB-YCbCr color space converter module 144 . Embodiments of the present invention may also cover the display pipeline 130 having any number of RGB-YCbCr color space converter modules 144 and any number of YCbCr-RGB color space converter modules 148 .

In an embodiment in which the pixel data is displayed on a television screen, the display pipeline 130 further includes an industry standard RGB-YCbCr color space converter module 150 to convert the pixel data to the YCbCr space. The industry standard RGB-YCbCr color space converter module 150 operates with a digital-to-analog converter (DAC) 162 to display pixel data on a television screen.

In an embodiment in which the pixel data is displayed on a CRT, the display pipeline 130 further includes a digital-to-analog converter (DAC) 161 to convert the pixel data from digital to analog form prior to display on the CRT. .

It should be understood that the computer system 100 is exemplary and that various changes and modifications are possible. Computer system 100 may be a desktop computer, server, laptop computer, palmtop computer, tablet computer, game console, set-top box, personal digital appliance, tethered Internet appliance, portable gaming system, cellular/mobile phone, based A computer emulator, or similar device. Display device 100 may be any pixel-based display, such as a CRT or LCD monitor, projector, printer, and the like. In some cases, multiple display devices (eg, an array of projectors or CRT monitors) may be supported, with each device displaying a portion of the image data. The display pipeline 130 and the GPU 112 can be located on separate chips. GPU 112 or any of its components may be implemented using one or more programmable processors programmed with appropriate software, application specific integrated circuits (ASICs), other integrated circuit technologies, or any combination thereof. Based on the present disclosure, those skilled in the art will appreciate that the present invention can be implemented in a wide variety of system configurations.

FIG. 2 is a flowchart of a method 200 for converting pixel data from an RGB space to a YCbCr space according to an embodiment of the present invention. At step 210, a luminance color component (Y) of the pixel data is determined using the following equation:

Y=R/4+G/2+B/4, (1)

Where R is the red component of the pixel data, G is the green component of the pixel data, and B is the blue component of the pixel data. The color space factor of the red component is one quarter or 0.25 - which is an approximation of the color space factor of 0.299 for the red component according to industry standard color space converters. The color space factor of the green component is one-half or 0.5 - which is also an approximation of the color space factor of 0.587 for the green component according to industry standard color space converters. The color space factor of the blue component is one-quarter or 0.25 - which is also an approximation of the color space factor of 0.114 for the blue component according to industry standard color space converters. Therefore, the color space coefficients selected for calculating the luminance color component (Y) according to equation (1) are in binary form. Since the color space coefficients are in binary form, binary arithmetic can be used to calculate the luma color component (Y) and multiplication is avoided. In this way, the luminance color component (Y) of the pixel data can be determined in a relatively cheap way.

According to an embodiment of the present invention, the luminance component (Y) of the pixel data may be determined according to a logic diagram 310 illustrated in FIG. 3A . Thus, the luminance color component (Y) of the pixel data is determined by shifting the green component to the left by one bit (which is equivalent to multiplying by 2), adding the result obtained to the red component and the the blue component and shift the sum to the right by two bits (which is equivalent to dividing by 4). In one embodiment, logic diagram 310 may be improved by performing a digital rounding operation before shifting the sum to the right by two bits. This rounding of numbers can be implemented using conventional techniques, such as multiplying one equal to 2 to the power of the number of shifts minus 1 before shifting the sum right (that is, 2( ^s-1 ), where s is the number of shifts ) is added to the sum. From a cost and computing resource point of view, left and right shift operations can be freely performed. Thus, the luma color component (Y) of the pixel data can be determined in a relatively inexpensive manner using the shift left and shift right operations described in logic diagram 310 .

At step 220, a blue difference component (Cb) of the pixel data is determined using the following equation:

Cb=(B-Y)/2, (2)

where B is the blue component of the pixel data and Y is the luminance color component (Y) of the pixel data determined at step 210 . Similar to the color coefficients used in Equation (1), the color space coefficients used in Equation (2) to determine the blue difference component (Cb) are obtained after determining the blue difference component according to an industry standard color space converter An approximation of the color space coefficients used in (Cb). In this way, the color space coefficients for determining the blue color difference component (Cb) according to equation (2) can be expressed in binary form. Since the color space coefficients are in binary form, binary arithmetic can be used to calculate the blue difference component (Cb) of the pixel data and avoid the use of multiplication. In this way, the blue difference component (Cb) of the pixel data can be determined in a relatively inexpensive manner.

According to an embodiment of the present invention, the blue difference component (Cb) of the pixel data can be determined according to a logic diagram 320 illustrated in FIG. 3B . Thus, the blue color difference component (Cb) of the pixel data can be determined by subtracting the brightness color component (Y) of the pixel data determined at step 210 from the blue component of the pixel data and Shift the sum right by one bit (which is equivalent to dividing by 2). In one embodiment, a digital rounding operation may be performed before right shifting the sum by one bit. As described above, since the right shift operation can be freely performed, the blue difference component (Cb) of the pixel data can be determined using the right shift operation described in logic diagram 320 in a relatively inexpensive manner.

At step 230, a red difference component (Cr) of the pixel data is determined using the following equation:

Cr=(R-Y)/2, (3)

Where R is the red component of the pixel data and Y is the luminance color component of the pixel data determined at step 210 . As in steps 210 and 220, the color space coefficients used to determine the red difference component (Cr) according to equation (3) are also an approximation of industry standard color coefficients so that the color space coefficients can be expressed as binary form. Since the color coefficients are in binary form, binary arithmetic can be used to calculate the red difference component (Cr) of the pixel data and avoid the use of multiplication. In this way, the red difference (Cr) of the pixel data can be determined in a relatively low-cost manner.

In an embodiment of the present invention, the red difference (Cr) of the pixel data can be determined according to a logic diagram 330 illustrated in FIG. 3C . Referring to FIG. 3C, the red difference component (Cr) of the pixel data is determined by subtracting the luminance color component (Y) of the pixel data from the red component of the pixel data, and dividing the obtained The result is right shifted by one bit (which is equivalent to dividing by 2). In one embodiment, a digital rounding operation may be performed before right shifting the result by one bit. As described above, since the right shift operation is free to perform, the red difference component (Cr) of the pixel data can be determined in a relatively inexpensive manner using the right shift operation illustrated in logic diagram 330 .

FIG. 4 is a flowchart of a method 400 for vertically scaling pixel data according to an embodiment of the present invention. At step 410, the chroma decimator 145 downsamples the blue differential component (Cb) and the red differential component (Cr) of the pixel data by a factor of two. In one embodiment, chroma decimator 145 reduces the sampling rate from a 4:4:4 sampling rate to a 4:2:2 sampling rate. In this way, the memory requirement for storing the pixel data is reduced by a third, and thus the size requirement for the line storage memory 170 is reduced. Although the sampling rate is reduced by a factor of two, embodiments of the invention contemplate that the sampling rate may be reduced by any factor.

Once the blue differential (Cb) and red differential (Cr) components of the pixel data have been sampled by a factor of two, the pixel data is stored in line store memory 170 (step 420). At step 430 , vertical scaler 146 vertically scales the pixel data stored in line store memory 170 . The pixel data may be vertically scaled by any vertical scaling technique known to those skilled in the art. For example, a new output row may be generated by interpolating between stored previous rows using a finite impulse response (FIR) interpolator. By changing the interpolation position relative to the input lines, a new image can be formed with a different number of lines than the input image.

Once the pixel data has been vertically scaled, chroma interpolator 147 increases the sampling rate by a factor of 2 for the blue difference component (Cb) and the red difference component (Cr) of the pixel data. In one embodiment, chroma decimator 147 increases the sampling rate from a 4:2:2 sampling rate to a 4:4:4 sampling rate. In this way, chroma interpolator 147 restores the original sampling rate of the blue (Cb) and red (Cr) differential components of the pixel data. In one embodiment, method 400 is programmable in that method 400 can only be invoked if the size of row store memory 170 divided by the number of rows in vertical scaler 146 is less than the row length.

Once the pixel data has been vertically scaled according to method 400, the pixel data may be converted from the YCbCr space to the RGB space. To this end, FIG. 5 illustrates a flowchart of a method 500 for converting pixel data from the YCbCr space to the RGB space according to an embodiment of the invention. At step 510, a red component (R) of the pixel data is determined using the following equation:

R=Y+2Cr, (4)

Where Y is the brightness color component of the pixel data and Cr is the red difference component of the pixel data. As in the steps described with reference to Figure 2, the color space coefficients used to determine the red component (R) according to equation (4) are also an approximation of the industry standard color coefficients so that the color The spatial coefficients are expressed in a binary form. Since the color coefficients are in binary form, binary arithmetic can be used to calculate the red component (R) of the pixel data and avoid the use of multiplication. In this way, the red component (R) of the pixel data can be determined in a relatively inexpensive way.

According to an embodiment of the present invention, the red component (R) of the pixel data may be determined according to a logic diagram 610 illustrated in FIG. 6A . Referring now to FIG. 6A, the red component (R) of the pixel data is determined by shifting the red difference component (Cr) of the pixel data to the left by one bit (which is equivalent to multiplying by 2), and multiplying the resulting The result of is added to the luma color component (Y) of the pixel data. As described above, the red component (R) of the pixel data can be determined using the left shift operation described in logic diagram 610 in a relatively inexpensive manner since the left shift operation is free to be performed.

At step 520, a green component (G) of the pixel data is determined using the following equation:

G=Y-Cb-Cr, (5)

Where Y is the luminance color component of the pixel data, Cb is the blue difference component of the pixel data and Cr is the red difference component of the pixel data. As in step 510, the color space coefficients used to determine the green component (G) according to equation (5) are also an approximation of the industry standard color coefficients so that the color space coefficients can be expressed as a binary form. Since the color coefficients are in a binary form, binary arithmetic can be used to calculate the green component (G) of the pixel data and multiplication is avoided. In this way, the green component (G) of the pixel data is determined in a relatively inexpensive manner.

According to an embodiment of the present invention, the green component (G) of the pixel data may be determined according to a logic diagram 620 illustrated in FIG. 6B . Referring now to FIG. 6B, the green component (G) of the pixel data is determined by subtracting the blue difference component (Cb) of the pixel data from the luminance color component Y of the pixel data, and further from The red difference Cr is subtracted from the result.

At step 530, a blue component (B) of the pixel data is determined using the following equation:

B=Y+2Cb, (6)

where Y is the luminance color component of the pixel data and Cb is the blue difference component of the pixel data. As in steps 510 and 520, the color space coefficients used to determine the blue component (B) according to equation (6) are also in a binary form. Thus, the blue component (B) of the pixel data can be calculated using a binary algorithm and avoiding the use of multiplication, thereby enabling a relatively inexpensive method of determining the blue component (B) of the pixel data.

According to an embodiment of the present invention, the blue component (B) of the pixel data may be determined according to a logic diagram 630 illustrated in FIG. 6C. Referring now to FIG. 6C, the blue component (B) of the pixel data is determined by shifting the blue difference Cr of the pixel data by one bit to the left (which is equivalent to multiplying by 2) and multiplying the resulting The result is added to the luminance color component Y of the pixel data. As described above, the blue component (B) of the pixel data can be determined using the left shift operation described in logic diagram 630 in a relatively inexpensive manner since the left shift operation is free to perform.

Although the above mainly discusses embodiments of the invention, other and further embodiments of the invention are also conceivable without departing from the basic scope of the invention, which is to be determined by the appended claims .

Claims (24)

1. An image processing device, comprising: a red, green and blue (RGB) color space-luminance color, blue difference and red difference (YCbCr) color space converter module for converting a row of pixels from said RGB color space to said YCbCr color space, wherein The row of pixels has a first sampling rate; a chroma decimator module coupled to the RGB-YCbCr color space converter module, wherein the chroma decimator module is configured to generate a color image with a sampling rate lower than the first sampling rate for the row of pixels an intermediate representation at a second sampling rate, wherein the amount of data representing the intermediate representation is less than the amount of data representing the row of pixels; a line store memory coupled to the chroma decimator module, wherein the line store memory is configured to store the intermediate representation; and A vertical scaler module coupled to the line store memory, wherein the vertical scaler module is configured to generate a scaled version of the intermediate representation. 2. The image processing apparatus of claim 1, further comprising a chroma interpolator module coupled to the vertical scaler module, wherein the chroma interpolator module is configured to convert the intermediate The scaled version of the representation at the second sampling rate is converted to a scaled version of the row of pixels at the first sampling rate. 3. The image processing device according to claim 2, further comprising a YCbCr-RGB color space converter module coupled to the chroma interpolator module, wherein the YCbCr-RGB color space converter module is passed configured to convert the scaled version of the row of pixels from the YCbCr color space to the RGB color space. 4. The image processing apparatus according to claim 1, wherein said second sampling rate is half of said first sampling rate. 5. The image processing apparatus of claim 1, wherein the first sampling rate is a 4:4:4 sampling rate and the second sampling rate is a 4:2:2 sampling rate. 6. The image processing apparatus of claim 1, wherein the RGB-YCbCr color space converter module converts the row of pixels using a binary algorithm. 7. The image processing device according to claim 1, wherein said RGB-YCbCr color space converter module determines a luminance color component (Y) of said row of pixels by: One quarter of the red (R) component is added to one half of a green (G) component of the row of pixels and one quarter of a blue (B) component of the row of pixels. 8. The image processing device as claimed in claim 1, wherein said RGB-YCbCr color space converter module determines a blue difference component (Cb) of said row of pixels by: from said blue color (B ) subtract the brightness color component (Y) of the row of pixels from the component; and divide the result by 2. 9. The image processing device according to claim 1, wherein said RGB-YCbCr color space converter module determines a red color difference (Cr) of said row of pixels by: subtracting the luminance color component (Y) of the row of pixels from the red (R) component; and dividing the result by 2. 10. The image processing device according to claim 3, wherein said YCbCr-RGB color space converter module determines said red (R) component of said row of pixels by converting said luminance color component ( Y) is added to twice the red difference amount (Cr) of the row of pixels. 11. The image processing apparatus according to claim 3, wherein said YCbCr-RGB color space converter module determines said green (G) component of said row of pixels by: Subtracting the red difference component (Cr) and the blue difference component (Cb) of the row of pixels from the brightness color component (Y). 12. The image processing device according to claim 3, wherein said YCbCr-RGB color space converter module determines said blue (B) component of said row of pixels by: The luminance color component (Y) is added to twice the blue difference component (Cb) of the row of pixels. 13. A method for vertically scaling a row of pixels, comprising: receiving the row of pixels in a red, blue, and green (RGB) color space, wherein the row of pixels includes a first sampling rate; converting the row of pixels from the RGB color space to a luminance, blue difference, and red difference (YCbCr) color space; generating an intermediate representation of the row of pixels having a second sampling rate lower than the first sampling rate; generating a scaled version of the intermediate representation; and converting the scaled version of the intermediate representation at the second sampling rate to a scaled version of the row of pixels at the first sampling rate. 14. The method of claim 13, further comprising storing the intermediate representation to a line store memory prior to generating the scaled version of the intermediate representation. 15. The method of claim 13, further comprising converting the scaled version of the row of pixels from the YCbCr color space to the RGB color space. 16. The method of claim 13, wherein the second sampling rate is half the first sampling rate. 17. The method of claim 13, wherein the first sampling rate is a 4:4:4 sampling rate and the second sampling rate is a 4:2:2 sampling rate. 18. The method of claim 13, wherein converting the row of pixels from the RGB color space to the YCbCr color space comprises converting the row of pixels using a binary algorithm. 19. The method of claim 13, wherein converting the row of pixels from the RGB color space to the YCbCr color space comprises generating a luminance color component (Y) by converting the row of pixels to One quarter of a red (R) component is added to one half of a green (G) component of the row of pixels and one quarter of a blue (B) component of the row of pixels. 20. The method of claim 13, wherein converting the row of pixels from the RGB color space to the YCbCr color space comprises generating the blue difference component (Cb) of the row of pixels by: subtracting the luma color component (Y) of the row of pixels from the blue (B) component; and dividing the result by two. 21. The method of claim 13, wherein converting the row of pixels from the RGB color space to the YCbCr color space comprises generating the red difference component (Cr) of the row of pixels by: subtracting the luma color component (Y) of the row of pixels from the red (R) component of the row of pixels; and dividing the result by two. 22. The method of claim 15, wherein converting said scaled version of said row of pixels from said YCbCr color space to said RGB color space comprises generating said Red (R) component: add the luminance color component (Y) of the row of pixels to twice the red difference component (Cr) of the row of pixels. 23. The method of claim 15, wherein converting said scaled version of said row of pixels from said YCbCr color space to said RGB color space comprises generating said Green (G) component: subtracting the red difference component (Cr) of the row of pixels and the blue difference component (Cb) of the row of pixels from the brightness color component (Y) of the row of pixels . 24. The method of claim 15, wherein converting said scaled version of said row of pixels from said YCbCr color space to said RGB color space comprises generating said Blue (B) component: Add the luminance color component (Y) of the row of pixels to twice the blue difference component (Cb) of the row of pixels.

Images