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101-809: Edinburgh Place Ferry Pier , often referred to as the "Star Ferry" Pier , was a pier in Edinburgh Place , Central, Hong Kong , serving the Star Ferry . The pier, with its clock tower, was a prominent waterfront landmark. Built in 1957 at the height of the Modern Movement , it was the third generation of the Star Ferry Pier in Central, and was located near the City Hall and the General Post Office . The pier

202-408: A computer-aided design model, often as non-uniform rational B-spline surfaces. Hand-held laser scanners can combine this data with passive, visible-light sensors — which capture surface textures and colors — to build (or " reverse engineer ") a full 3D model. Structured-light 3D scanners project a pattern of light on the subject and look at the deformation of the pattern on the subject. The pattern

303-461: A 3D image through the triangulation mechanism described above: a laser dot or line is projected onto an object from a hand-held device and a sensor (typically a charge-coupled device or position sensitive device ) measures the distance to the surface. Data is collected in relation to an internal coordinate system and therefore to collect data where the scanner is in motion the position of the scanner must be determined. The position can be determined by

404-489: A 3D scan directly inside SolidWorks . Still other CAD applications are robust enough to manipulate limited points or polygon models within the CAD environment (e.g., CATIA , AutoCAD , Revit ). CT , industrial CT , MRI , or micro-CT scanners do not produce point clouds but a set of 2D slices (each termed a "tomogram") which are then 'stacked together' to produce a 3D representation. There are several ways to do this depending on

505-406: A 3D scanner describes the distance to a surface at each point in the picture. This allows the three dimensional position of each point in the picture to be identified. In some situations, a single scan will not produce a complete model of the subject. Multiple scans, from different directions are usually helpful to obtain information about all sides of the subject. These scans have to be brought into

606-618: A 60-metre (200 ft) high bungee jump over the North Sea waves. The present pier is a successor of an earlier pier, which was completed in 1901 but in 1943 destroyed by the German occupation forces. The first recorded pier in England was Ryde Pier , opened in 1814 on the Isle of Wight , as a landing stage to allow ferries to and from the mainland to berth. It is still used for this purpose today. It also had

707-512: A block of overlapped images is the primary approach for 3D mapping and object reconstruction using 2D images. Close-range photogrammetry has also matured to the level where cameras or digital cameras can be used to capture the close-look images of objects, e.g., buildings, and reconstruct them using the very same theory as the aerial photogrammetry. An example of software which could do this is Vexcel FotoG 5. This software has now been replaced by Vexcel GeoSynth . Another similar software program

808-657: A common reference system , a process that is usually called alignment or registration , and then merged to create a complete 3D model. This whole process, going from the single range map to the whole model, is usually known as the 3D scanning pipeline. There are a variety of technologies for digitally acquiring the shape of a 3D object. The techniques work with most or all sensor types including optical, acoustic, laser scanning, radar, thermal, and seismic. 3D-scan technologies can be split in 2 categories: contact and non-contact. Non-contact solutions can be further divided into two main categories, active and passive. There are

909-448: A complementary airborne model. The airborne modeling process generates a half-meter resolution model with a bird's-eye view of the entire area, containing terrain profile and building tops. Ground-based modeling process results in a detailed model of the building facades. Using the DSM obtained from airborne laser scans, they localize the acquisition vehicle and register the ground-based facades to

1010-747: A digital representation of an object and its interior, such as non destructive materials testing, reverse engineering , or studying biological and paleontological specimens. Passive 3D imaging solutions do not emit any kind of radiation themselves, but instead rely on detecting reflected ambient radiation. Most solutions of this type detect visible light because it is a readily available ambient radiation. Other types of radiation, such as infrared could also be used. Passive methods can be very cheap, because in most cases they do not need particular hardware but simple digital cameras. Photogrammetry provides reliable information about 3D shapes of physical objects based on analysis of photographic images. The resulting 3D data

1111-406: A given set of stereo points from images. Multi-spectral images are also used for 3D building detection. The first and last pulse data and the normalized difference vegetation index are used in the process. New measurement techniques are also employed to obtain measurements of and between objects from single images by using the projection, or the shadow as well as their combination. This technology

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1212-510: A human chain at the entrance of the construction site so as to try to stop the construction crew and machines from further demolishing the site. In addition to the public, Civic Party legislators, and Choy So-yuk , a councillor from the pro-government Democratic Alliance for the Betterment of Hong Kong , showed up to lend support. The demolition drew widespread condemnation from the public, legislators, and conservationists, all of whom claimed

1313-623: A leisure function in the past, with the pier head once containing a pavilion, and there are still refreshment facilities today. The oldest cast iron pier in the world is Town Pier, Gravesend , in Kent , which opened in 1834. However, it is not recognised by the National Piers Society as being a seaside pier. Following the building of the world's first seaside pier at Ryde, the pier became fashionable at seaside resorts in England and Wales during

1414-627: A lengthier trek to reach the new pier. By relocating the new piers 300 m away, it is estimated that the Star Ferry could lose perhaps 13 per cent or more of passengers due to its inconvenience. On the Tsim Sha Tsui side of the harbour, the proposed relocation of the bus terminus which acts as a feeder for the ferry is forecast to further reduce passenger numbers by one-fifth. This loss, totalling one-third of its passengers, would translate into revenue loss of some HK$ 17 million per annum for Star Ferry. Architects and conservationists argued that

1515-647: A linear littoral quayside, and such piers are usually much shorter. Typically each pier would carry a single transit shed the length of the pier, with ships berthing bow or stern in to the shore. Some major ports consisted of large numbers of such piers lining the foreshore, classic examples being the Hudson River frontage of New York , or the Embarcadero in San Francisco . The advent of container shipping , with its need for large container handling spaces adjacent to

1616-471: A new pier was built in 1933. It remained till the present day, but was partially transformed and modernized in 1999–2004. In Nieuwpoort, Belgium there is a pleasure pier on both sides of the river IJzer . Scheveningen , the coastal resort town of The Hague , boasts the largest pier in the Netherlands , completed in 1961. A crane, built on top of the pier's panorama tower, provides the opportunity to make

1717-554: A number of other historical sites threatened with a similar fate. At the end of 2006, in a testament to how the protests have struck a chord with the public, the Ferry protesters were voted "Person of the Year" by RTHK Radio 3 . Local Action, the group of rather young cultural and media activists which formed the core of the movement, were to later influence social movements, in Hong Kong as well as in

1818-556: A pier has two decks. Galveston Island Historic Pleasure Pier in Galveston , Texas has a roller coaster, 15 rides, carnival games and souvenir shops. Early pleasure piers were of complete timber construction, as was with Margate which opened in 1824. The first iron and timber built pleasure pier Margate Jetty , opened in 1855. Margate pier was wrecked by a storm in January 1978 and not repaired. The longest iron pleasure pier still remaining

1919-451: A pier presents a set of different circumstances to fishing from the shore or beach, as you do not need to cast out into the deeper water. This being the case there are specific fishing rigs that have been created specifically for pier fishing which allow for the direct access to deeper water. In Blankenberge a first pleasure pier was built in 1894. After its destruction in the World War I ,

2020-734: A real-world object or environment to collect three dimensional data of its shape and possibly its appearance (e.g. color). The collected data can then be used to construct digital 3D models . A 3D scanner can be based on many different technologies, each with its own limitations, advantages and costs. Many limitations in the kind of objects that can be digitised are still present. For example, optical technology may encounter many difficulties with dark, shiny, reflective or transparent objects. For example, industrial computed tomography scanning , structured-light 3D scanners , LiDAR and Time Of Flight 3D Scanners can be used to construct digital 3D models , without destructive testing . Collected 3D data

2121-489: A reconstruction project. An example of existing ground plan data usable in building reconstruction is the Digital Cadastral map , which provides information on the distribution of property, including the borders of all agricultural areas and the ground plans of existing buildings. Additionally information as street names and the usage of buildings (e.g. garage, residential building, office block, industrial building, church)

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2222-456: A second, but high resolution scans, requiring millions of samples, can take minutes for some time-of-flight scanners. The problem this creates is distortion from motion. Since each point is sampled at a different time, any motion in the subject or the scanner will distort the collected data. Thus, it is usually necessary to mount both the subject and the scanner on stable platforms and minimise vibration. Using these scanners to scan objects in motion

2323-452: A set of planar surfaces and straight lines. Further processing such as expressing building footprints as polygons is used for data storing in GIS databases. Using laser scans and images taken from ground level and a bird's-eye perspective, Fruh and Zakhor present an approach to automatically create textured 3D city models. This approach involves registering and merging the detailed facade models with

2424-522: A temporary road through the Edinburgh Place and that the Government has never consulted the public regarding demolition of the pier, or the adjacent Queen's Pier. After the demolition of the pier, the government said that it would consider the memories of the citizens and not the historic value of the building/structure before demolishing it. Conservationists vowed to take the fight to Queen's Pier, and

2525-412: A topographical information system has been developed by Franz Rottensteiner. His approach was based on the integration of building parameter estimations into the photogrammetry process applying a hybrid modeling scheme. Buildings are decomposed into a set of simple primitives that are reconstructed individually and are then combined by Boolean operators. The internal data structure of both the primitives and

2626-402: A triangle. The length of one side of the triangle, the distance between the camera and the laser emitter is known. The angle of the laser emitter corner is also known. The angle of the camera corner can be determined by looking at the location of the laser dot in the camera's field of view. These three pieces of information fully determine the shape and size of the triangle and give the location of

2727-650: A variety of technologies that fall under each of these categories. Contact 3D scanners work by physically probing (touching) the part and recording the position of the sensor as the probe moves around the part. There are two main types of contact 3D scanners: Both modern CMMs and Articulated Arms can also be fitted with non-contact laser scanners instead of touch probes. Active scanners emit some kind of radiation or light and detect its reflection or radiation passing through object in order to probe an object or environment. Possible types of emissions used include light, ultrasound or x-ray. The time-of-flight 3D laser scanner

2828-438: Is Microsoft Photosynth . A semi-automatic method for acquiring 3D topologically structured data from 2D aerial stereo images has been presented by Sisi Zlatanova . The process involves the manual digitizing of a number of points necessary for automatically reconstructing the 3D objects. Each reconstructed object is validated by superimposition of its wire frame graphics in the stereo model. The topologically structured 3D data

2929-542: Is a must on their itinerary. No other ferry pier along the harbour could possibly perform such a symbolic function as this clocktower pier. The removal of the Star Ferry Pier to Piers 4–7 leading to its destruction would likely raise public objection and dismay. However, the Government had maintained that the Pier and its tower was not old enough to be classified as "historical" and that people were not necessarily "concerned about

3030-414: Is also a possibility. Again, this approach allows modelling without physically moving towards the location or object. From airborne lidar data, digital surface model (DSM) can be generated and then the objects higher than the ground are automatically detected from the DSM. Based on general knowledge about buildings, geometric characteristics such as size, height and shape information are then used to separate

3131-440: Is an active scanner that uses laser light to probe the subject. At the heart of this type of scanner is a time-of-flight laser range finder . The laser range finder finds the distance of a surface by timing the round-trip time of a pulse of light. A laser is used to emit a pulse of light and the amount of time before the reflected light is seen by a detector is measured. Since the speed of light c {\displaystyle c}

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3232-623: Is at Southend-on-Sea , Essex , and extends 1.3 miles (2.1 km) into the Thames Estuary . The longest pier on the West Coast of the US is the Santa Cruz Wharf , with a length of 2,745 feet (837 m). Providing a walkway out to sea, pleasure piers often include amusements and theatres as part of their attractions. Such a pier may be unroofed, closed, or partly open and partly closed. Sometimes

3333-439: Is known, the round-trip time determines the travel distance of the light, which is twice the distance between the scanner and the surface. If t {\displaystyle t} is the round-trip time, then distance is equal to c ⋅ t / 2 {\displaystyle \textstyle c\!\cdot \!t/2} . The accuracy of a time-of-flight 3D laser scanner depends on how precisely we can measure

3434-441: Is projected onto the subject using either an LCD projector or other stable light source. A camera, offset slightly from the pattern projector, looks at the shape of the pattern and calculates the distance of every point in the field of view. Structured-light scanning is still a very active area of research with many research papers published each year. Perfect maps have also been proven useful as structured light patterns that solve

3535-585: Is provided in the form of text symbols. At the moment the Digital Cadastral map is built up as a database covering an area, mainly composed by digitizing preexisting maps or plans. The point clouds produced by 3D scanners and 3D imaging can be used directly for measurement and visualisation in the architecture and construction world. Most applications, however, use instead polygonal 3D models, NURBS surface models, or editable feature-based CAD models (aka solid models ). These CAD models describe not simply

3636-412: Is set on a tripod and there is strong sunlight on one side of the scanner then that side of the tripod will expand and slowly distort the scan data from one side to another. Some laser scanners have level compensators built into them to counteract any movement of the scanner during the scan process. In a conoscopic system, a laser beam is projected onto the surface and then the immediate reflection along

3737-431: Is stored in a database and are also used for visualization of the objects. Notable software used for 3D data acquisition using 2D images include e.g. Agisoft Metashape , RealityCapture , and ENSAIS Engineering College TIPHON (Traitement d'Image et PHOtogrammétrie Numérique). A method for semi-automatic building extraction together with a concept for storing building models alongside terrain and other topographic data in

3838-485: Is that, due to the high speed of light, measuring the round-trip time is difficult and so the accuracy of the distance measurement is relatively low, on the order of millimetres. Triangulation range finders, on the other hand, have a range of usually limited to a few meters for reasonably sized devices, but their accuracy is relatively high. The accuracy of triangulation range finders is on the order of tens of micrometers . Time-of-flight scanners' accuracy can be lost when

3939-477: Is the one at Southend. First opened as a wooden pier in 1829, it was reconstructed in iron and completed in 1889. In a 2006 UK poll, the public voted the seaside pier onto the list of icons of England. Many piers are built for the purpose of providing boatless anglers access to fishing grounds that are otherwise inaccessible. Many "Free Piers" are available in larger harbors which differ from private piers. Free Piers are often primarily used for fishing. Fishing from

4040-655: Is typically provided as a 3D point cloud, 3D mesh or 3D points. Modern photogrammetry software applications automatically analyze a large number of digital images for 3D reconstruction, however manual interaction may be required if the software cannot automatically determine the 3D positions of the camera in the images which is an essential step in the reconstruction pipeline. Various software packages are available including PhotoModeler , Geodetic Systems , Autodesk ReCap , RealityCapture and Agisoft Metashape (see comparison of photogrammetry software ). Semi-automatic building extraction from lidar data and high-resolution images

4141-450: Is useful for a wide variety of applications. These devices are used extensively by the entertainment industry in the production of movies and video games, including virtual reality . Other common applications of this technology include augmented reality , motion capture , gesture recognition , robotic mapping , industrial design , orthotics and prosthetics , reverse engineering and prototyping , quality control /inspection and

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4242-407: Is very difficult. Recently, there has been research on compensating for distortion from small amounts of vibration and distortions due to motion and/or rotation. Short-range laser scanners can not usually encompass a depth of field more than 1 meter. When scanning in one position for any length of time slight movement can occur in the scanner position due to changes in temperature. If the scanner

4343-448: The t {\displaystyle t} time: 3.3 picoseconds (approx.) is the time taken for light to travel 1 millimetre. The laser range finder only detects the distance of one point in its direction of view. Thus, the scanner scans its entire field of view one point at a time by changing the range finder's direction of view to scan different points. The view direction of the laser range finder can be changed either by rotating

4444-681: The Architectural Office (AO) of the Hong Kong Government from 1952 to 1957 as an assistant architect. He designed the façade of the pier, and the Chief Architect, Michael Wright, added the Clock Tower to make the pier more balanced and practical. The chimes of the turret clock installed at the pier marked every quarter-hour since the pier's inauguration in 1957. The clock was a gift from John Keswick , who had in turn received it from

4545-561: The Central Ferry Piers dates back to July 1999, when proposed amendments to the draft Central District (Extension) Outline Zoning Plan covering the Central Reclamation III area were published. Both the third generation Star Ferry Pier and Queen's Pier would be demolished and 16 hectares of land directly in front of the fourth-generation pier reclaimed to make way for a six-lane road and a low-rise shopping centre. The cost

4646-613: The Victorian era , peaking in the 1860s with 22 being built in that decade. A symbol of the typical British seaside holiday, by 1914, more than 100 pleasure piers were located around the UK coast. Regarded as being among the finest Victorian architecture, there are still a significant number of seaside piers of architectural merit still standing, although some have been lost, including Margate , two at Brighton in East Sussex , one at New Brighton in

4747-561: The Wirral and three at Blackpool in Lancashire . Two piers, Brighton's now derelict West Pier and Clevedon Pier , were Grade 1 listed . The Birnbeck Pier in Weston-super-Mare is the only pier in the world linked to an island. The National Piers Society gives a figure of 55 surviving seaside piers in England and Wales. 3D scanning 3D scanning is the process of analyzing

4848-601: The correspondence problem and allow for error detection and error correction. The advantage of structured-light 3D scanners is speed and precision. Instead of scanning one point at a time, structured light scanners scan multiple points or the entire field of view at once. Scanning an entire field of view in a fraction of a second reduces or eliminates the problem of distortion from motion. Some existing systems are capable of scanning moving objects in real-time. A real-time scanner using digital fringe projection and phase-shifting technique (certain kinds of structured light methods)

4949-408: The digitization of cultural artifacts. The purpose of a 3D scanner is usually to create a 3D model . This 3D model consists of a polygon mesh or point cloud of geometric samples on the surface of the subject. These points can then be used to extrapolate the shape of the subject (a process called reconstruction ). If colour information is collected at each point, then the colours or textures on

5050-451: The health of sandy beaches and navigation channels . Pleasure piers were first built in Britain during the early 19th century. The earliest structures were Ryde Pier , built in 1813/4, Trinity Chain Pier near Leith, built in 1821, Brighton Chain Pier , built in 1823. and Margate Jetty 1823/24 originally a timber built pier. Only the oldest of these piers still remains. At that time,

5151-515: The "third generation" pier was situated was created in the late 1950s following a major land reclamation . The shoreline was shifted from its position at the time, level to the Mandarin Hotel . The pier was built in 1957 in Edinburgh Place , at the height of the Modern Movement , near the City Hall complex which was being planned at the time. The Star Ferry Pier was designed by a local Chinese architect, Hung Yip Chan (born in 1921). He worked in

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5252-478: The Air , and Earth Care jointly met to urge the public to fight for the preservation of the pier. Over 1,000 signatures were collected on that one day alone, in a petition to be submitted to Chief Executive Donald Tsang and other senior officials. In addition, a group of protesters began a peaceful sit-in that day. So Sau Chung , veteran campaigner (now a monk), whose hunger strike against Star Ferry fare increases triggered

5353-458: The Central reclamation noted the pier's significant role in Hong Kong's transport history. The Government was warned that a public backlash could be expected when the full implications of the reclamation were known. The Pier, especially its clock tower, is a visually important landmark in Hong Kong. It is an eye-catching icon within the beautiful Hong Kong Harbour particularly for tourists and locals crossing it via Star Ferries from Tsim Sha Tsui. It

5454-662: The Prince of Belgium. The mechanism was manufactured by British company Edward John Dent , which also provided the mechanical signature to " Big Ben " of London. There is a major bus terminus on the Kowloon side, which is conveniently situated close to the Tsim Sha Tsui Ferry Pier . Thousands of residents passed through this principal gateway to Hong Kong Island from the Kowloon Peninsula daily from 1957 until 2006. However,

5555-409: The airborne model by means of Monte Carlo localization (MCL). Finally, the two models are merged with different resolutions to obtain a 3D model. Using an airborne laser altimeter, Haala, Brenner and Anders combined height data with the existing ground plans of buildings. The ground plans of buildings had already been acquired either in analog form by maps and plans or digitally in a 2D GIS. The project

5656-442: The binary defocusing technique, speed breakthroughs have been made that could reach hundreds to thousands of frames per second. Modulated light 3D scanners shine a continually changing light at the subject. Usually the light source simply cycles its amplitude in a sinusoidal pattern. A camera detects the reflected light and the amount the pattern is shifted by determines the distance the light travelled. Modulated light also allows

5757-504: The body than computed tomography (CT) does, making it especially useful in neurological (brain), musculoskeletal, cardiovascular, and oncological (cancer) imaging. These techniques produce a discrete 3D volumetric representation that can be directly visualised , manipulated or converted to traditional 3D surface by mean of isosurface extraction algorithms . Although most common in medicine, industrial computed tomography , microtomography and MRI are also used in other fields for acquiring

5858-502: The building itself". To some extent, it was not wrong, since the activists were mainly fighting for the preservation of a public place and against the methods and urban planning policies of its government, perceived to favour business interests over the public interest. The struggle to preserve the Star Ferry and, later, the Queen's Pier, was the occasion to raise questions on Hong Kong's history,

5959-489: The buildings from other objects. The extracted building outlines are then simplified using an orthogonal algorithm to obtain better cartographic quality. Watershed analysis can be conducted to extract the ridgelines of building roofs. The ridgelines as well as slope information are used to classify the buildings per type. The buildings are then reconstructed using three parametric building models (flat, gabled, hipped). Lidar and other terrestrial laser scanning technology offers

6060-458: The clock tower, including moving the proposed six-lane road or relocating the clock tower to the front of the new pier as a memorial. One reason cited by the Government against the relocation of the turret clock and tower was that an expert feasibility study advised that there was "no guarantee the clock and chimes would continue to work after relocation, due to their age and obsolete components". However, Neil Brennon Wright of Thwaites & Reed ,

6161-399: The complete six degrees of freedom of the scanner. Both techniques tend to use infrared light-emitting diodes attached to the scanner which are seen by the camera(s) through filters providing resilience to ambient lighting. Data is collected by a computer and recorded as data points within three-dimensional space , with processing this can be converted into a triangulated mesh and then

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6262-514: The compound building models are based on the boundary representation methods Multiple images are used in Zhang's approach to surface reconstruction from multiple images. A central idea is to explore the integration of both 3D stereo data and 2D calibrated images. This approach is motivated by the fact that only robust and accurate feature points that survived the geometry scrutiny of multiple images are reconstructed in space. The density insufficiency and

6363-456: The envelope or shape of the object, but CAD models also embody the "design intent" (i.e., critical features and their relationship to other features). An example of design intent not evident in the shape alone might be a brake drum's lug bolts, which must be concentric with the hole in the centre of the drum. This knowledge would drive the sequence and method of creating the CAD model; a designer with an awareness of this relationship would not design

6464-411: The environment. With respect to time-of-flight 3D laser scanner the triangulation laser shines a laser on the subject and exploits a camera to look for the location of the laser dot. Depending on how far away the laser strikes a surface, the laser dot appears at different places in the camera's field of view. This technique is called triangulation because the laser dot, the camera and the laser emitter form

6565-577: The fastest, automated way to collect height or distance information. lidar or laser for height measurement of buildings is becoming very promising. Commercial applications of both airborne lidar and ground laser scanning technology have proven to be fast and accurate methods for building height extraction. The building extraction task is needed to determine building locations, ground elevation, orientations, building size, rooftop heights, etc. Most buildings are described to sufficient details in terms of general polyhedra, i.e., their boundaries can be represented by

6666-582: The fishing and cargo industries and serves as a port for large cruise ships in the area. Many other working piers have been demolished, or remain derelict, but some have been recycled as pleasure piers. The best known example of this is Pier 39 in San Francisco . At Southport and the Tweed River on the Gold Coast in Australia , there are piers that support equipment for a sand bypassing system that maintains

6767-522: The glare of publicity. Although the scale of the phase 3 reclamation in Central was cut back from 32 to 18 hectares, the fate of the piers was sealed by the reclamation. The pier became the centre of a bitter struggle between the Government and conservationists , who opposed either further destruction of the harbour or the further loss of historical buildings. Consultants who prepared the Environmental Impact Assessment report in 2001 for

6868-407: The government action was contrary to the wishes of the public. Legco members tabled motions to immediately halt the demolition, pending further consultation. The Government denied a last-minute reprieve, reiterating that there has been "adequate consultation", and forged ahead with demolition. The Conservancy Association claimed it made its objection known in 1996 when Government proposed to construct

6969-564: The image of a Victorian cast iron pleasure pier. However, the earliest piers pre-date the Victorian age . Piers can be categorized into different groupings according to the principal purpose. However, there is considerable overlap between these categories. For example, pleasure piers often also allow for the docking of pleasure steamers and other similar craft, while working piers have often been converted to leisure use after being rendered obsolete by advanced developments in cargo-handling technology. Many piers are floating piers, to ensure that

7070-590: The inauguration of the Cross-Harbour Tunnel in 1972 popularised vehicular travel across the harbour and reduced the flow of passengers. From 1972 to 2006, the ferry was still used by many as the shortest route from Tsim Sha Tsui (TST) to Central District, and a daily average of 74,000 passenger trips were made across the harbour in 2004. On the island side, various New World First Bus and Citybus bus routes as well as public light buses connected to many destinations on Hong Kong Island. The plan to relocate

7171-412: The inevitable holes in the stereo data should then be filled in by using information from multiple images. The idea is thus to first construct small surface patches from stereo points, then to progressively propagate only reliable patches in their neighborhood from images into the whole surface using a best-first strategy. The problem thus reduces to searching for an optimal local surface patch going through

7272-453: The introduction of steamships and railways for the first time permitted mass tourism to dedicated seaside resorts . The large tidal ranges at many such resorts meant that passengers arriving by pleasure steamer could use a pier to disembark safely. Also, for much of the day, the sea was not visible from the shore and the pleasure pier permitted holidaymakers to promenade over and alongside the sea at all times. The world's longest pleasure pier

7373-452: The laser dot corner of the triangle. In most cases a laser stripe, instead of a single laser dot, is swept across the object to speed up the acquisition process. The use of triangulation to measure distances dates to antiquity. Time-of-flight range finders are capable of operating over long distances on the order of kilometres. These scanners are thus suitable for scanning large structures like buildings or geographic features. A disadvantage

7474-440: The laser hits the edge of an object because the information that is sent back to the scanner is from two different locations for one laser pulse. The coordinate relative to the scanner's position for a point that has hit the edge of an object will be calculated based on an average and therefore will put the point in the wrong place. When using a high resolution scan on an object the chances of the beam hitting an edge are increased and

7575-457: The lug bolts referenced to the outside diameter, but instead, to the center. A modeler creating a CAD model will want to include both Shape and design intent in the complete CAD model. Vendors offer different approaches to getting to the parametric CAD model. Some export the NURBS surfaces and leave it to the CAD designer to complete the model in CAD (e.g., Geomagic , Imageware, Rhino 3D ). Others use

7676-731: The mainland: part of the more militant "post 80s" generation, they are critical of government business collusion, a one-sided development approach, Hong Kong's subordinate status within China and the perceived lack of democracy in the territory, and have been involved in the fight for real political reform in Hong Kong , and against the Express Rail link to Guangzhou . 22°17′1″N 114°9′37.5″E  /  22.28361°N 114.160417°E  / 22.28361; 114.160417 Pier Piers have been built for several purposes, and because these different purposes have distinct regional variances,

7777-454: The output required: Laser scanning describes the general method to sample or scan a surface using laser technology. Several areas of application exist that mainly differ in the power of the lasers that are used, and in the results of the scanning process. Low laser power is used when the scanned surface doesn't have to be influenced, e.g. when it only has to be digitised. Confocal or 3D laser scanning are methods to get information about

7878-399: The pier and clock tower. The demolition crew took control of the site by erecting scaffolding on 6 December 2006, and demolition commenced on 12 December. Workers took down the clock mechanism and clock face, leaving a gaping hole, and then proceeded to lift the clock tower off in one piece. After the protesters had been dispersed, the remainder of the pier was completely dismantled, away from

7979-461: The pier stretching far enough off shore to reach deep water at low tide. Such piers provided an economical alternative to impounded docks where cargo volumes were low, or where specialist bulk cargo was handled, such as at coal piers . The other form of working pier, often called the finger pier, was built at ports with smaller tidal ranges. Here the principal advantage was to give a greater available quay length for ships to berth against compared to

8080-573: The pier was architecturally significant to Hong Kong as one of the last remaining examples of a Streamline Moderne public building (along with the Central Market and Wan Chai Market which have been earmarked for demolition); culturally the pier was widely recognised as a part of local collective memory. The Hong Kong Institute of Architects warned against the destruction of Hong Kong's heritage, saying it would be an irreversible mistake. Public opinion has resulted in alternatives put forward to preserve

8181-603: The piers raise and lower with the tide along with the boats tied to them. This prevents a situation where lines become overly taut or loose by rising or lowering tides. An overly taut or loose tie-line can damage boats by pulling them out of the water or allowing them so much leeway that they bang forcefully against the sides of the pier. Working piers were built for the handling of passengers and cargo onto and off ships or (as at Wigan Pier ) canal boats. Working piers themselves fall into two different groups. Longer individual piers are often found at ports with large tidal ranges , with

8282-448: The question of colonialism, and that of democracy in the HKSAR. The Government had grossly underestimated the very strong public sentiment about this 49-year-old landmark in the " collective memory " of Hong Kong residents. By its own retrospective admission, it lacked legitimacy: a Government spokesman conceded that the it had failed to gain the moral high ground. Ferry passengers would face

8383-517: The range finder itself, or by using a system of rotating mirrors. The latter method is commonly used because mirrors are much lighter and can thus be rotated much faster and with greater accuracy. Typical time-of-flight 3D laser scanners can measure the distance of 10,000~100,000 points every second. Time-of-flight devices are also available in a 2D configuration. This is referred to as a time-of-flight camera . Triangulation based 3D laser scanners are also active scanners that use laser light to probe

8484-420: The resulting data will show noise just behind the edges of the object. Scanners with a smaller beam width will help to solve this problem but will be limited by range as the beam width will increase over distance. Software can also help by determining that the first object to be hit by the laser beam should cancel out the second. At a rate of 10,000 sample points per second, low resolution scans can take less than

8585-528: The riots in 1966, came by to lend his support. Further spurred by the start of demolition on the afternoon of 12 December 2006, more protesters started gathering spontaneously after workers removed the bell and the clock face from the tower, leaving a big hole. Activists, including "Long Hair" Leung Kwok-hung , rushed into and occupied part of the demolition site, chanting slogans from the roof of an excavator and demanded to meet Secretary for Housing, Planning and Lands , Michael Suen Ming-yeung . Protesters formed

8686-427: The same ray-path are put through a conoscopic crystal and projected onto a CCD. The result is a diffraction pattern , that can be frequency analyzed to determine the distance to the measured surface. The main advantage with conoscopic holography is that only a single ray-path is needed for measuring, thus giving an opportunity to measure for instance the depth of a finely drilled hole. Hand-held laser scanners create

8787-403: The scan data to create an editable and verifiable feature based model that is imported into CAD with full feature tree intact, yielding a complete, native CAD model, capturing both shape and design intent (e.g. Geomagic , Rapidform). For instance, the market offers various plug-ins for established CAD-programs, such as SolidWorks. Xtract3D, DezignWorks and Geomagic for SolidWorks allow manipulating

8888-531: The scanned surface. Another low-power application uses structured light projection systems for solar cell flatness metrology, enabling stress calculation throughout in excess of 2000 wafers per hour. The laser power used for laser scanning equipment in industrial applications is typically less than 1W. The power level is usually on the order of 200 mW or less but sometimes more. 3D data acquisition and object reconstruction can be performed using stereo image pairs. Stereo photogrammetry or photogrammetry based on

8989-418: The scanner to ignore light from sources other than a laser, so there is no interference. Computed tomography (CT) is a medical imaging method which generates a three-dimensional image of the inside of an object from a large series of two-dimensional X-ray images, similarly magnetic resonance imaging is another medical imaging technique that provides much greater contrast between the different soft tissues of

9090-432: The scanner using reference features on the surface being scanned (typically adhesive reflective tabs, but natural features have been also used in research work) or by using an external tracking method. External tracking often takes the form of a laser tracker (to provide the sensor position) with integrated camera (to determine the orientation of the scanner) or a photogrammetric solution using 3 or more cameras providing

9191-495: The shipping berths, has made working piers obsolete for the handling of general cargo, although some still survive for the handling of passenger ships or bulk cargos. One example, is in use in Progreso, Yucatán , where a pier extends more than 4 miles into the Gulf of Mexico , making it the longest pier in the world. The Progreso Pier supplies much of the peninsula with transportation for

9292-539: The special occasion, Star Ferry hosted a "last ride" before the pier was closed-down, with the last four ferries leaving this pier on the stroke of midnight. Eighteen hundred Hongkongers willingly paid up $ 88 (40 times the normal fare) for the last ride, whose proceeds were designated for charity. On 19 November 2006, the Civic Party , Democratic Party , Harbour-front Enhancement Committee, Hong Kong Institute of Architects , People's Sustainable Development Committee, Clear

9393-443: The surface of the subject can also be determined. 3D scanners share several traits with cameras. Like most cameras, they have a cone-like field of view , and like cameras, they can only collect information about surfaces that are not obscured. While a camera collects colour information about surfaces within its field of view , a 3D scanner collects distance information about surfaces within its field of view. The "picture" produced by

9494-510: The term pier tends to have different nuances of meaning in different parts of the world. Thus in North America and Australia , where many ports were, until recently, built on the multiple pier model, the term tends to imply a current or former cargo-handling facility. In contrast, in Europe , where ports more often use basins and river-side quays than piers, the term is principally associated with

9595-485: The world's longest operating clockmaking firm, who arrived from England on 18 December 2006 to examine the clock, said that his firm had restored far worse. The Government promised that it would "rebuild" the chimes of the clock, complete with the restitution of the original clock faces and mechanism at some nearby location. The public outcry, anticipated by the consultancy report for the Antiquities and Monuments Office ,

9696-551: Was applied to capture three-dimensional images of the pier before the demolition. Following the pier's decommissioning on 12 November 2006, demolition work started amidst protests. The demolition was originally scheduled for the early part of 2007, but demolition was brought forward by 3 months, to 12 December 2006. The government ignored a nonbinding motion in September in the Legislative Council of Hong Kong urging it to retain

9797-421: Was developed, to capture, reconstruct, and render high-density details of dynamically deformable objects (such as facial expressions) at 40 frames per second. Recently, another scanner has been developed. Different patterns can be applied to this system, and the frame rate for capturing and data processing achieves 120 frames per second. It can also scan isolated surfaces, for example two moving hands. By utilising

9898-668: Was done in order to enable an automatic data capture by the integration of these different types of information. Afterwards virtual reality city models are generated in the project by texture processing, e.g. by mapping of terrestrial images. The project demonstrated the feasibility of rapid acquisition of 3D urban GIS. Ground plans proved are another very important source of information for 3D building reconstruction. Compared to results of automatic procedures, these ground plans proved more reliable since they contain aggregated information which has been made explicit by human interpretation. For this reason, ground plans, can considerably reduce costs in

9999-576: Was estimated at HK$ 3.5 billion. The Government said that the historical significance of the third-generation pier would be recognised and promised to recreate the landmark on the new waterfront. In 2001, an impact assessment for the Central Reclamation recommended the relocation of the Star Ferry Pier, and this was approved by the Antiquities Advisory Board in 2002. 3D Laser Scanning Technology in digital recording of structures

10100-489: Was the central flashpoint of the Hong Kong riots in 1966 , and 40 years later became the focus of a confrontation between conservationists and the government, which wanted to demolish the pier to allow for reclamation . The ferry service from the pier was suspended on 11 November 2006, and moved to piers 7 and 8 of Central Piers . Demolition commenced on 12 December, and was completed in early 2007. The entire waterfront where

10201-422: Was to become reality. With the imminent threat of demolition, the local community rallied to save pier, to widespread media coverage. In the weeks running up to the cessation of service from the pier, thousands of Hong Kong residents arrived to post banners and other messages in support of retention. There were some 150,000 nostalgic visitors to the Pier and harbour crossing on the night of 11 November 2006. To mark

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