CHAPTER 1
INTRODUCTION Recent achievements in thermal acquisition systems have led to improvements in the capabilities of thermo-graphic methods for the non-destructive inspection of metallic and composite panels. In most cases pulsed transient thermography involves heating the surface of a target structure for a short period of time followed by the capture of the thermal decay using an infrared camera. Present-day systems enable the recording, storage, and processing of hundreds of digitized images at very fast rates. The thermal images are typically analysed for the presence of hot spots which may indicate the existence of subsurface noise/defects. Noise of subsurface is produced due to local temperature caused by the friction of the ball. Noise of multiple nature and optical distortions produce difficulties for the interpretation of the recorded data. Post-processing is a powerful tool for the determination of the shapes and sizes of subsurface noise/defects in inspected subjects. Any suspected snick or bat/pad event can be verified by examining the infrared image, which usually shows a bright spot where contact friction from the ball has elevated the local temperature. Regular video image analysis combined with special methods based on heat conduction theory can be applied to each scan stored in the computer memory. Several informative parameters of thermal response after heating realizing amplitude, temporal, and phase methods are currently used for enhancement of flaw images. The physical limitations of the informative parameters can be found by conducting analytical and numerical simulations of thermal flow propagation through a material. In the present work, how do Infra-red camera works? Thermal infrared imagers are detector and lens combinations that give a visual representation of infrared energy emitted by objects. Thermal infrared images let you see heat and how it is distributed. A thermal infrared camera detects infrared energy and converts it into an electronic signal, which is then processed to produce a thermal image and perform temperature calculations. Thermal imaging cameras have lenses, just like visible light cameras. But in this case the lens focuses waves from infrared energy onto an infrared sensor array. Thousands of sensors on the array convert the infrared energy into electrical signals, which are then converted into an image.
1.1 Literature survey Thermo-graphic cameras have become all the rage lately in the world of cricket. When properly used, these can reduce the room for error with LBW or out-caught/caughtbehind decisions and can accurately determine whether the ball had made contact with the batsman's bat, pad, glove or any other part of the body. Of course, the expense of setting up the two-camera solution at each match is very high (a thermo-graphic camera goes for roughly $30,000). The technology has been made available to the third umpire as part of the referral system on several occasions but the use of this technology is by no means mandatory. Several current and former players are in favour of making it mandatory. Michael Vaughan recently was quoted on BBC Sport as saying: "the ICC should pay for the Snicko and Hotspot at every Test match venue." TV audiences enjoy the application of this technology giving the broadcaster another avenue for advertising. In fact, spectators voted it the best piece of technology in cricket in a Cricket Australia poll in 2007. BBG's Hotspot thermo-graphic technology got 54 per cent of the vote followed by extreme slow-motion (22 per cent), Hawk-Eye (14 per cent), Snickometer (6 per cent) and 3-tracker (5 per cent). First invented by Nicholas Bion of France, the technology is now used for wideranging applications including security and defence. Nine Network of Australia adopted it for cricket and the technology is now offered by the Australian companyBBG Sports. First used in 2006-07 Ashes Test match at the Gabba in November of 2006, cricket constitutes the first sporting application currently for this technology. It is considered more accurate than the Snickometer, which relies on sound. This technology can be used to find: i) The correct LBW decision, so that any edge from the bat can be easily detected with the help of this technology. ii) When it comes to any keeper catch even the slight edge or nick can also be detected with the help of this technology. In recent years of cricket one of the major problem in cricket is the umpire's decision and if this umpire's decision goes wrong in the case of any main
batsman who is crucial for the team to win the match. This has happened many times and that too these LBW decisions. Well, this Hotspot technology is most often used in two important cases, i) Caught behind- Did the batsman Nick the ball?
The image below is good enough to explain the given situation. Well, when we consider this in ordinary images or videos, we might feel that the batsman must have nick it and with the deviation produced, the umpire would have given out and as a result of that the batsman would be the unluckiest man. But with the use of this technology we can help the batsman in knowing the truth that the ball had stuck the pad and not the bat, with the help of the white spot which is produced on the pad. Another issue which can be discussed from the image from the viewer‟s point is that the question of LBW, if the umpire had the idea of giving him LBW. And any cricket fan can easily guess with the help of this hot spot that the ball misses the off stump. And so this technology of hotspot made the job of umpire easier and in fact in future this can also be a danger for umpire, as they can replace them, which results in losing their job.
FIG 1.1
ii) LBW - inside edge or not?
FIG 1.2
The above image is a evidence to prove that a batsman is out LBW or not. The image is clear enough that the batsman didn't have any inside image as there is no white spot in the bat, rather the white spot is found in the pads and it is very clear that the batsman is out LBW. But this is given out most of the time LBW and the confusion arises when the umpires gives any batsman out LBW without knowing that, there was an inside edge. So all these controversies can be overcome with the help of these hotspot technologies
1.1.1 Umpires vs. Hotspot
Most often, the biggest mistake that the umpire commit is in these LBW decisions and that too many batsmen where given out LBW, in-spite of the inside edge and we should not blame umpires for this, because they are also humans "to err is human"......... So the main purpose why this technology was invented is to find whether the batsman has edge it or the ball has struck directly on the pad. This determination is enough to find whether a batsman is out or not, in the case of caught behind of LBW decision.
The introduction of this technology is not an ordinary step, because earlier this technology was used in the military to by the tanks and also by the jets so that they could trace any of their enemies, and these was used particularly in countries like Australia. Those who watch cricket regularly might have known which country started using this technology first. It is Australia and we might have seen these technologies were used during the Ashes when England team travelled Australia and also during the Indian matches that were played in Australia. But now this technology is used in every country and it was also accepted as the best technology as it gives the accurate decision, which was not in the case of Hawk Eye, which was used for LBW decision, and that too the hotspot technology used for finding caught behind, in the case of any slight edge, and in the LBW decision, whether to find the ball has struck directly on the pad or it has any inside edge, very accurate. This technology was first used in the 2006-2007 Ashes series on 23rd November 2006 at the Gabba, Brisbane cricket stadium by the Australian Nine network. Moreover this technology was first adapted for television by the BBG Sports, which is an Australian company who earlier introduced the technology called Snickometer, in conjunction with Sky Sports.
1.1.2 Know their technology -How Hot Spot is used?
When it comes to this technology we need the following requirements to ensure this technology is available i). The TV broadcasting channel who is involved in the Live telecasting of the matches, uses many cameras in the ground so that they could get the different angles. They must also spend money to use two infra-red cameras on the ground. ii). These two infra-red cameras are used at the either side of the ground, i.e. where they have the side screen, so that they could clearly have the view of the batsman when he faces the ball. The reason why we need to use 2 cameras at the either side is that in cricket, after every over it is the keeper who changes the side and so after each over the bowler will bowl from different end.
After installing the cameras, the hot spot images can be used whenever any controversial decision was made and we can get the accurate decision with the help of these hot spot images and especially for the LBW and when the batsman snick the ball. Well, the working of this technology can be very easily understood. Whenever the batsman is in contact with the ball, then the IR cameras which are set on the either side of the ground will send these images to the computer and in the next process all these images are converted into a negative image. Now the IR cameras which are fixed on the either side has a great function, because they have the capability to sense and measure any heat produced due to the friction generated by a collision, which includes i). Meeting of the ball to the bat. ii) When the ball strikes the pad or any other parts of the body. So when these images are processed into negative images and in case if the ball has struck the bat/pad, then we can see a white spot in those images, which are resulted due to the heat produced when the bat/pad and ball meets. 1.1.3 Practical Examples
In simple way we can express; while considering two simple examples, i). Whenever we slap a person, we are applying some force and then we strike them and at this instant, the heat is produced due the friction that occurs between the face and hands is captured using IR cameras then, we could easily detect the region of impact.
. FIG 1.3
An image is represented using a 3*4 pixel frame. The pixel values just before the slap is shown in Table-1.1 and the pixel values of the frame at the time of slap is shown in Table1.2. The pixel values in Table-1.1 are due to the body temperature and the values in Table-1.2 is due to rise in body temperature as a result of slap.
12
13
12
12
14
12
11
12
12
12
12
12
Table-1.1
13
15
15
16
13
140
14
15
15
16
16
16
Table-1.2
The pixel with the intensity value 140 is the pixel in which the slap has occurred. The brightest (warmest) parts of the image are customarily colored white, intermediate temperatures red and yellow, and the dimmest (coolest) parts blue.
1.2 Organization of the report The entire report has been categorized into 5 chapters Chapter 1 gives the introductory knowledge about how the hot-spot technology came in to
existence, technology detailing “A Picture is Worth a Thousand Words.” the objective of the project and the literature survey.
Chapter 2 technology used behind image-processing in hot-spot (region of interest), impact
of the technology described in terms of advantages/disadvantages & applications. Chapter 3 Chapter 4 Chapter 5 conclusion & future enhancement.
CHAPTER 2
TECHNOLOGY USED Hot spot technology is an infra-red imaging system which is most popularly used in sports especially in cricket to determine whether the ball has actually struck the player‟s bat/pad or even the ground. On any snick or bat-pad event occurs, the infrared camera sends an image through to a computer which then turns it into negative image showing us the outcome of the recent incident. The image shows us any heat been produced in the field of play, giving us a 100% accurate conclusion on the decision. The main aim of this technology is to successfully make a decision on whether the batsman is dismissed or granted „not out‟, or either the ball has hit the bat; pad and glove or it has hit something. Hotspot technology uses two infra-red cameras which are positioned at either end of ground above the field of play that are continuously recording an image that show the miniscule amount of heat generated from friction when two objects collide. Collision occurs when ball hits the pad, bat or ground. Infra-red sensors are electronic devices that sense and measure infra-red radiations emitting from objects in its field of view. Infra-red camera‟s records the event in form of video. Infra-red sensors assign intensity values to each pixel in the frame. These frames will be transmitted to the computer which is placed in-front of the third umpire. Now the third umpire uses subtraction technique to generate a series of black and white images and to locate a white spot and thus he can easily adjudicate whether the batsman is out or not.
FIG 2.1
The image above shows a white colored mark on the bat which can be viewed only with the help of the Hotspot technology, which uses the Infra-red cameras to detect it. From the above figure, most of the cricket fans might have recognized this is the image of Sachin Tendulkar, we can clearly see how the batsman clearly connects the ball with the bat and from the friction produced when the ball strikes the bat, these hotspots are developed. The image above is just to show you how the hot spot marks are used. The whole process can be divided into two phases. In the first phase an infra-red camera records the event in its field of view and the infra-red sensors will assign pixel intensity values to each pixel in the frame. When there is a collision, heat is produced as a result of friction. The pixels in which there is collision will be having much higher pixel intensity values than the other pixels in the frame. The software is so calibrated that a high intensity value pixel generates white color and lower intensity value pixels give a dark color. The subtraction technique used in the first phase is dark frame subtraction. It is done in-order to minimize image noise for pictures taken with long exposure times and to generate high contrast images. After performing dark frame subtraction the high contrast frames will be sent to the computer which is placed in front of the third umpire. The first phase ends here.
2.1 DARK FRAME SUBTRACTION In digital photography, dark frame subtraction is a way to minimize image noise for pictures taken with long exposure times. It takes advantage of the fact that a component of image noise, known as fixed-pattern noise, is the same from shot to shot: noise from the
sensor, dead or hot pixels. It works by taking a picture with the shutter closed. A dark frame is an image captured with the sensor in the dark, essentially just an image of noise in an image sensor. A dark frame, or an average of several dark frames, can then be subtracted from subsequent images to correct the fixed-pattern noise such as that caused by dark current. Dark frame subtraction has been done for some time in scientific imaging; some consumer digital cameras do it automatically. Visible fixed-pattern noise is often caused by hot pixels – pixel sensors with higher than normal dark current. On long exposure, they can appear as bright pixels. Sensors on the CCD that always appears as brighter pixels are called stuck pixels while sensors that only brighten up after long exposure are called hot pixels. The dark frame subtraction technique is also used in digital photogrammetry, to improve the contrast of satellite and air photograms. In the second phase the third umpire uses another subtraction technique known as digital subtraction angiography (DSA) to generate a series of negative images. Images in this case are usually taken at 2 - 3 frames per second, which allows to evaluate the trajectory of the ball on its way. This technique "subtracts" the other background images and contrast agent can be seen. Thus eventually we will be able to produce a white patch on the image where the ball that has actually struck the batsman‟s pad or bat or anything on its way
through.
2.2 DIGITAL SUBTRACTION ANGIOGRAPHY (DSA) TECHNIQUE In this technology images are produced using contrast medium by subtracting a 'precontrast image' or the mask from later images, once the contrast medium has been introduced into a structure. Hence the term 'digital subtraction angiography'. This is a technology which was developed for medical purposes. Digital Subtraction Angiography (DSA) is a type of fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment. This technology was later adopted for hotspot for locating white patches by subtracting a pre-contrast image or the mask image from later images. In our case, the precontrast image refers to the image that is taken just before there is a collision. The contrast medium is the collision, in which a ball striking the bat, pad, glove, ground or any other thing in the field of view is captured using infra-red camera. The latter image is the image that is obtained at the point of collision.
All the pixels in the frame will be having pixel intensity values. The frames in the pixels in which there is collision will be having much higher pixel intensity values. A high intensity value pixel generates white color and lower intensity value pixels give a dark color. The latter image will be having some pixels which are having much higher pixel intensity values than the pre-contrast image. These differences in the pixel intensity values of precontrast image and latter image help in locating a white patch in the new frame. This new frame is obtained by subtracting a pre-contrast image from a latter image. The software produces a series of negative frames. By observing these frame we will be able to reach a conclusion whether there is a contact within the region of interest in the field of view of the infra-red camera.
2.3 WHITE PATCH DEVELOPMENT In digital subtraction angiography a new image will be obtained by subtracting the pre-contrast image from a latter image. All the pixels in the frame will be assigned a pixel value. The latter image which is the image showing collision will be having some pixels with much higher pixel intensity value. This higher intensity value is due to the collision which produces heat. This heat causes a rise in pixel intensity value. So when the pre-contrast image is subtracted from a latter image so pixels will be higher values and those pixels in which there is no action will be having lesser intensity values. The higher intensity value pixel will be seen as white and the lower intensity value pixels will be seen as dark colors, mostly black. 10
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8
10
11
12
8
13
15
14
9
15
100
15
8
7
11
8
9
10
11
9
8
Table 1.1
Frame just before collision (Pre-contrast frame)
Table 1.2
Frame in which collision occurs (Latter frame)
0
0
0
0
2
85
1
1
3
0
1
1
Table 2.3 (Resultant frame)
Above there are three 3*4 frames shown. First frame is the pre-contrast frame. Second frame is the latter frame. Third frame is the resultant frame. Pixel intensity values are assigned to each pixel in the frames. In the latter frame there is one pixel which is having much higher intensity value than other pixels. That means that is the pixel in which there is a collision. The resultant frame is obtained by subtracting pre-contrast frame from the latter frame. In the new frame there is one pixel higher intensity value. That will appear white. All other pixels in the frame are having lesser intensity values so they will appear as dark probably black. The pixel which is showed as white is the pixel in which there is collision. Thus a white patch is obtained.
2.4 Advantages and Disadvantages Hot Spot has two main advantages over its competing technology, the Snickometer, which is a sound-detection based system. Snickometer often produces inconclusive results indicating contact (potentially any combination of bat, pad and ball) only, whereas the Hot Spot clearly shows exactly what the ball strikes. Applying Vaseline on the edge of the cricket- bat doesn‟t affect the technology. Hotspot technology, even though claimed to be extremely accurate, is not used in many matches. The main reason for this is its expense: $6000 per day for the use of two cameras and $10000 for the use of four cameras. However, In the recently held India-England ODI Series 2011, there were controversial decisions based on the hot spot technology going against India's Rahul Dravid on more than one occasion where hot spot replays proved inconclusive and yet Dravid was given out. On one occasion, there seemed to be a nick which hot spot wasn't able to detect. These incidents threw the role of hotspot technology into doubt once again. Hot Spot, had earlier said the device's accuracy was around 90-95 per cent and could be impacted by factors like bright sunshine and the speed of the bat in the shot.
2.5 Applications 1. Infra-red imaging technology that enhances the road safety.
Fig a.
Fig b.
As you can clearly see from the figures Fig a. and Fig b. the use of the technology magnificently increases the road safety. 2. It is used in the Security defence surveillance, military tankers & air-crafts. 3. It is also used in biological and medical applications. 4. Roof damage (including detection of broken PV panels), locating the source of a leak or hidden water damage, air infiltration around doors, windows, problems with HVAC units and hidden electrical problems. 5. Implemented in satellite-imaging and solar system tracking.
CHAPTER 5
CONCLUSION Hotspot is one of the most accepted and accurate technology which is used at present in most of the cricket matches. In spite of accuracy used in this technology, ICC hasn't made this technology to be used officially. With the use of this technology we can help the batsman in knowing the truth that the ball had stuck the pad and not the bat, with the help of the white spot which is produced on the pad. This technology of hotspot made the job of umpire easier and in fact in future this can also be a danger for umpire, as they can replace them, which results in losing their job. Anyone can easily guess with the help of this hot spot that the ball misses the off stump.
Hotspot has a particular advantage over its competing technology, the Snickometer, which is a sound-detection based system. Snickometer often produces inconclusive results indicating contact (potentially any combination of bat, pad and ball) only, whereas the Hot Spot clearly shows exactly what the ball strikes. Hotspot technology, even though it is extremely accurate, is not used in many matches. The main reason for this is its expense: $6000 per day for the use of two cameras and $10000 for the use of four cameras. Thus, some less wealthy countries do not use the technology so as to conserve money. Usage of hotspot technology in cricket also cost time. So there should be rules for asking hotspot referrals so that the game speed doesn‟t get compromised. The
challenge is to ensure the pace of the game is maintained and also it remains a fair deal.
5.1 FUTURE ENHANCEMENT Hotspot is one of the most accepted and accurate technology which is used at present in most of the cricket matches. In spite of accuracy used in this technology, ICC hasn't made this technology to be used officially. This technology is used in every country and it was also accepted as the best technology as it gives the accurate decision, which was not in the case of Hawk Eye, which was used for LBW decision, and that too the hotspot technology used for finding caught behind, in the case of any slight edge, and in the LBW decision, whether to find the ball has struck directly on the pad or it has any inside edge, very precise. Usage of advanced micro-lens in Infra-red imaging technology can greatly impact the enhanced feature of this technology. This technology is likely to be used in the upcoming ICC cricket world cup. Hotspot technology is having the backing of science to get 100% accurate conclusion on a decision. There are two main issues in implementing this technology. One is the cost in implementing this technology and other is; it actually slows the speed of the game. So there should be rules for asking hotspot referrals so that the game speed doesn‟t get compromised. And also use of improved technology improves the game-
play. The challenge is to ensure the pace of the game is maintained and also it remains a fair deal.
BIBLIOGRAPHY [1] http://en.wikipedia.org/wiki/Hot_Spot_(cricket) [2] http://www.itsonlycricket.com/entry/437 [3] http://www.cricinfo.com/ciicc/content/story/393605.htm [4] http://www.dreamcricket.com/community/blogs/cricgear/archive/2010/08/04/hot-spottechnology-gains-popularity.aspx
