Nowadays, many types of electronic devices are being used as you can see people around you may hold a nomadic at least and some of them may transport more than one of these appliances ; nomadic phone, laptop, MP3 participant, PDA, etc. Therefore, we might hold to accept the truth that these equipments significantly influence on our daily activities. Ocular applications of the electronic tool are extremely important every bit good as the others because we can state that about houses will hold at least one of ocular electronic device such as Television ( Television Set ) , Personal computer ( Personal Computer ) , etc. The family contraption will hold a monitor/screen and it can be watched really frequently every twenty-four hours therefore we can attach some equipment to them and do them more utile than they have been utilizing. The extra tools need to supply more functionality to the bing one.
Picture-in-picture is another interesting engineering to unify into this application because we can expose another beginning of image or picture on the same show unit. The engineering is fundamentally used in Television to expose another channel ( s ) in inset screen ( s ) at the same clip as another full Television screen exposing.
Figure 1 – Picture-in-picture in Television sets.
To understand the design procedure, we need to make the experiment over and over until we obtained the most effectual consequence before execution of the existent production. Thus this demand of fast and flexible solution is critical, if we have to do the concluding merchandise every clip we have tested. It would non be appropriate in footings of cost and clip cachexia ; hence, field-programmable gate array ( FPGA ) can be another solution for the designing. We can plan, debug, verify and imitate the paradigm with many alterations or algorithms utilizing complex operations once more and once more within short period of clip which can salvage the development clip.
Figure 2 – Altera FPGA DE2-70 Development Board Layout and Peripherals
Altera FPGA DE2-70 Development Board is an option for this undertaking design because the device has many peripherals which can supply about equal resources of undertaking demand.
Cyclone II EP2C70 FPGA
250 M4K RAM blocks
150 embedded multipliers
622 user I/O pins
Two 32-Mbyte Single Data Rate Synchronous Dynamic RAM memory french friess
Organized as 4M x 16 spots x 4 Bankss
Accessible as memory for the Nios II processor and by the DE2-70 Control Panel
Uses the ADV7123 240-MHz ternary 10-bit high-velocity picture DAC
With 15-pin high-density D-sub connection
Supports up to 1600 ten 1200 at 100-Hz refresh rate
NTSC/PAL/ SECAM Television DECODER
Uses two ADV7180 Multi-format SDTV Video Decoders
Supports worldwide NTSC/PAL/SECAM colour demodulation
One 10-bit ADC, 4X over-sampling for CVBS
Supports Composite Video ( CVBS ) RCA doodly-squat input
Supports digital end product formats: 8-bit ITU-R BT.656 YCrCb 4:2:2 end product + HS, VS, and FIELD
The design would be based on digital signal processing ( DSP ) which besides be involved with arithmetic computation, memory direction, analog-to-digital convertor and digital-to-analog convertor.
One of Hardware Description Language ( HDL ) will be used to command FPGA and Verilog is one of the most normally used in the hierarchal design, confirmation and execution of digital logic french friess at the registry transportation degree ( RTL ) . Verilog HDL has some similarity of C programming linguistic communication which can be an advantage for interior decorators who has experienced from the scheduling linguistic communication. Verilog HDL allows interior decorators to implement switches, RTL, Gatess and custom behavioural codification within the same design.
REVIEW OF THE LITERATURE
2.1 COMPOSITE VIDEO TO DIGITAL VIDEO CONVERTER
In composite picture system, the luminosity and chrominance signal can be multiplexed within the same channel. The signal can be received by both of monochrome and coloring material receiving systems. The National Television Systems Committee ( NTSC ) systems take the advantage of the fact that the sensitiveness of human eyes is the most at the green visible radiation, less at the ruddy one and least at the bluish one by utilizing lower bandwidth for the chrominance ( coloring material ) signals compare to the luminosity ( brightness ) signal. This solution can cut down the bandwidth of the transmittal without losing the color signal quality.
In general, there are four common stairss to change over parallel signals to digital 1s. The system consists of filter, sampling station, quantiser and encoder. The picture signals are Y, Cr and Cb which can be discovered from these stairss.
Figure 3 Conversion of constituent parallel Television signals to digital Television signals
The definition of NTSC color infinite is known as YIQ which consist of these constituents: luminosity ( Y ) , hue ( I ) and impregnation ( Q ) . YIQ can be converted to RGB constituents or YUV constituents by the followers:
I? = 0.299R + 0.587G + 0.114B
?† = 0.596R – 0.274G – 0.322B
= – ( transgress 33A° ) U + ( cos 33A° ) Volt
Q = 0.211R – 0.523G + 0.311B
= ( cos 33A° ) U + ( transgress 33A° ) Volt
From the above expression, it has clearly seen that I? is being used for the strength of the luminosity in the color infinite therefore we can utilize the signal for grayscale image transition.
There is another coloring material infinite called YCbCr which has been the grading and offsetting of YUV color infinite. The color infinite is related to 8-bit RGB constituents as described below:
Y = 0.257R + 0.504G + 0.098B + 16
Cr = 0.439R – 0.368G – 0.071B + 128
Cb = -0.148R – 0.291G + 0.439B + 128
YCbCr could be more precise and it can be fitted in unsigned whole number 8-bit informations but Y is allowed to hold the scope of value from 16 to 235 and both of Cb and Cr can hold value between 16 and 240. The trying rate of the luminosity is 13.5 MHz and the chrominance is 6.75 MHz. NTSC ( 30 frames/second ) will hold 720 active pixels per line and 480 active lines per one frame.
Due to the sensitiveness of homo to the luminosity or the brightness, we can salvage the bandwidth of signals which are being transmitted by compacting the chrominance or coloring material signals. The trying rate of 13.5MHz is being used for Y signal therefore YCbCr can be designated as 4: N: n. The bandwidth of Cb and Cr should be less than 13.5 MHz or equal.
THE 4:2:2 FORMAT
This technique can cut down the bandwidth of the chrominance signals by half which means if a luminosity sampling frequence is 13.5 MHz hence chrominance 1s would be 6.75 MHz. The method perform by trying Cb and Cr one-half of the figure of luminosity frequence. The chrominance declaration will be vertically sampled as figure below.
Figure 4: The YCbCr 4:2:2 Format
THE 4:4:4 FORMAT
This method will non try to cut down the use of bandwidth and the extra bandwidth could non be clearly seen the difference nevertheless it is being widely used in color infinite transition. For case, when we want to change over video format from one coloring material infinite to another, the signals need to be resampled in 4:4:4 format foremost. The luminosity and the chrominance signals will be transmitted at the same frequence. “ The 4:4:4 format is utile chiefly in computing machine artworks applications, where full chrominance declaration is required non merely in the perpendicular but besides in the horizontal way. “ ( Haskell, Puri, and Netravali, 2000, p. 94 )
Figure 5: The YCbCr 4:2:2 Format
INTERLACED AND NON-INTERLACED VIDEO
Interlaced picture is represented by utilizing 2 distinguishable images per frame on the same screen. One image be on odd-numbered raster lines and another image is on even-numbered raster lines nevertheless both will be combined to exhibit a same image at the same frame.
Figure 6: Interlaced Video Scaning
Non-interlaced picture is a type of raster scanning which consecutive scans raster lines from top to bottom within each frame. The whole screen has merely one peculiar image per frame. Therefore, all the vertically next scan lines are besides temporally next every bit good as gesture images. The picture system is besides known as ‘Progressive picture ‘ .
Figure 7: Interlaced and Non-Interlaced Video Scanning
2.2 VIDEO GRAPHICS ARRAY ( VGA )
VGA connection is 3-row of 5 pins DE-15 connection which is besides known as D-SUB 15 RGB connection. The connection is widely used in many computing machine proctor, picture in writing cards and high definition telecasting sets. Although the connection consists of 15 pins but there are merely 5 of import pins used to convey picture signals to the show devices.
Figure 8: DE-15 or D-SUB 15 Connection
VGA VIDEO SIGNAL
There are 5 active parallel signals will be transmitted through pin 1, 2, 3, 13 and 14 of DE-15 connection. The first two signals are horizontal and perpendicular synchronism signals which are compatible with TTL logic degrees. The other three signals are R ( ruddy ) , G ( green ) and B ( blue ) and they have 0.7 to 1.0 Volt peak-to-peak degree. Each signal will stand for primary base coloring material ; nevertheless, the difference and combination of the parallel signals level will command the coevals of video coloring material on VGA end product devices.
Figure 9: RGB Signals and Colours
VIDEO DISPLAY, REFRESH AND Timing
VGA computing machine proctor is a progressive scan system therefore an image on the screen will be generated from a sequence of horizontal lines. For illustration, the screen declaration 640 by 480 image elements ( pels ) . The screen should be able to redraw the whole screen 60 times per second for an image and to cut down spark. The period is well-known as “ Refresh Rate ” .
The spark can be noticed by human eyes when the refresh rate is less than 30 – 60 Hz. Personal computer proctors sometimes use 70 Hz of refresh rate instead than 60 Hz to cut down spark from fluorescent light beginning intervention. Every scanned pel will be generated by the value of RGB signal. For 640×480 declaration and 60 Hz ( 16.67 MS ) refresh rate, one pel needs about 40 Ns ( 25 MHz ) therefore 640 pels will necessitate ~25.60 Aµs the refresh rate will necessitate to be increased for higher declaration by higher clock rate.
Figure 10: VGA Signals and Clocking
Table 1: VGA Signals and Clocking
A frame of image on proctor will be started from top left of the screen and one pel at a peculiar clip will be plotted on the screen from left to compensate one time the last pel of the row has been created. The row reference will be increased and the column reference will besides be reset to the fist left column once more. The row reference has been controlled by the horizontal sync signal ( HSYNC ) . The procedure continues until the row reference come to the last row of the screen. At this clip an full frame of image has been successfully generated and both of column and row reference will be reset to the top left place or pel [ 0 ] [ 0 ] once more by confer withing the perpendicular sync signal ( VSYNC ) .
Figure 11: VGA HSYNC and VSYNC Signals
Resolution ( HxV )
Pixel clock ( MHz )
( 60Hz )
25 ( 640/c )
( 85Hz )
36 ( 640/c )
( 60Hz )
40 ( 800/c )
( 75Hz )
49 ( 800/c )
( 85Hz )
56 ( 800/c )
( 60Hz )
65 ( 1024/c )
( 70Hz )
75 ( 1024/c )
( 85Hz )
95 ( 1024/c )
( 60Hz )
108 ( 1280/c )
Table 2: VGA Mode, Resolution, Refresh Rate and Pixel Clock Rate
Computer proctor will observe the synchronal signals automatically and will non active if sync signals are non right. Active manner of the screen can be indicated by detecting the coloring material of an LED of the proctor. The LED coloring material will turn into green if the sync signals are right but it will be orange when the sync signals are out of scope.
2.3 DIGITAL IMAGE Processing
A digital image can be represented as a planar map or M x N mathematic array. The M is the figure of row and N is the figure of column of an image frame. The map can besides be described as degree Fahrenheit ( x, y ) when ten is the column figure start from top-left and Y is the row figure start from top of an image.
The coordination between x and y can be called pel every bit good as the value at a peculiar pel is well-known as strength in monochromatic image nevertheless the value will be formed by a combination of primary coloring materials: ruddy, green and bluish in color image.
Figure 12: Digital Image Coordination as Array
Mode of coloring material can be categorized by the deepness of pixel value. The followers are some illustrations.
1-bit monochromatic image: the value of each pel will be either ‘0 ‘ or ‘1 ‘ merely therefore the image will hold black and white coloring material. It is besides known as bi-level, two-level, binary or black-and-white image.
Figure 13: Binary Image
8-bit grayscale image: the value of each pel can be any value from the scope of 0 – 255. The weakest strength will be considered as 0 or black and the strongest one will hold a value of 255 or white.
Figure 14: Grayscale Image
24-bit RGB image: each pel will hold values of three 8-bit RGB colour The combination will supply 24 spots of informations per pel which means each pel will hold an unsigned whole number value 0 – 255.
32-bit RGB image: the image has 24-bit RGB value per pel including an extra 8-bit for transparence. The image can cover on another image on the screen.
Figure 14: 24-bit RGB Image
2.3.1 RGB TO GRAYSCALE CONVERSION
The strength of each grayscale image ‘s pel can be converted from RGB value by utilizing the equation below:
Grayscale = 0.299R + 0.587G + 0.114B
2.3.2 GRAYSCALE TO BINARY CONVERSION
Binary image would be utilizing in applications of image cleavage but we need to see the strength of the image which pel should be judged as black or white pel. To get the better of the job, thresholding will be consulted. There are two ways to find threshold: planetary thresholding and local thresholding.
Figure 15: Thresholding of Image Histogram
The strength histogram of an image can be used to separate objects from background. Pixels of object and background will hold two different groups of strength degrees. To do a determination, a threshold ( T ) of an image needs to be selected and used to compare every pel of the image.
AUTOMATIC GLOBAL THRESHOLDING
A threshold value ( T ) between the lower limit and maximal strength degrees will be ab initio chosen and it will be able to section the image into two groups
G1: The strength value is more than or equal Thymine
G2: The strength value is less than Thymine
Average strength values of pels in scopes G1 and G2 will be calculated and known as Aµ1 and Aµ2. The mean strength values will be used in the new threshold computation and continues the above process until predefined threshold value is met.
One histogram-based method called “ Otsu ‘s Algorithm ” is being widely used to take an optimal threshold value automatically. The algorithm believes that there are two different part values within an image ( e.g. background and foreground image ) and can be recognized by foremost get downing looking for a distinct chance strength degree.
= Total figure of pels in the image.
= Number of pels that have strength degree
L = Total figure of possible strength degrees in the image
A threshold K will be selected for a set of strengths [ 0, 1, aˆ¦ , k-1 ] or C0 and C1 will stand for a set of pixel strength [ K, k+1, aˆ¦ , L-1 ] . The algorithm will take the upper limit threshold value K from the between-class discrepancy ? 2B.
MANUAL GLOBAL THRESHOLDING
Threshold values can be chosen by test and mistake until an appropriate value is observed. This procedure is usually done by perceivers and the method is good for synergistic operation. However, indexs will necessitate to be provided for the operators.
We can hold an wrong threshold value from the planetary thresholding method when the background light is non even. We need to work out the light job by compensation or preprocessing the image before utilizing the planetary thresholding method to cipher the threshold value of the image.
Figure 16: Grayscale and Binary Image
2.3.3 EDGE DETECTION