The orthophoto image which is generated using an aerial photo is used in river management, road design and the various fields since the orthophoto has ability to visualize land use with position information. However, the image distortion often occurs in the ortho rectification process. This image distortion is used to estimate manually by the evaluation person with great time. The image distortion should be automatically estimated from the view point of efficiency of the process. With this motive, formed angle V between view vector at exposure point and normal vector at center point of a patch area was focused in this paper. In order to evaluate the relation between image distortion and formed angle V, DMC image which were acquired 2000m height were used and formed angle V for 10m×10m patch was adopted for computing visibility restriction. It was confirmed that image distortion occurred for the patch which show rather than 69 degree of the formed angle V. Therefore, it is concluded that efficient orthophoto visibility restriction is able to perform using the formed angle V as visibility restriction in this paper.
Proc. SPIE. 8085, Videometrics, Range Imaging, and Applications XI
KEYWORDS: Image compression, Digital photography, Image segmentation, Digital cameras, Orthophoto maps, Photogrammetry, Printing, High dynamic range imaging, Associative arrays, Time multiplexed optical shutter
High dynamic range imagery is widely used in remote sensing. With the widespread use of aerial digital cameras such as
the DMC, ADS40, RMK-D, and UltraCamD, high dynamic range imaging is generally expected for generating
minuteness orthophotos in digital aerial photogrammetry. However, high dynamic range images (12-bit, 4,096 gray
levels) are generally compressed into an 8-bit depth digital image (256 gray levels) owing to huge amount of data and
interface with peripherals such as monitors and printers. This means that a great deal of image data is eliminated from
the original image, and this introduces a new shadow problem. In particular, the influence of shadows in urban areas
causes serious problems when generating minuteness orthophotos and performing house detection. Therefore, shadow
problems can be solved by addressing the image compression problems.
There is a large body of literature on image compression techniques such as logarithmic compression and tone mapping
algorithms. However, logarithmic compression tends to cause loss of details in dark and/or light areas. Furthermore, the
logarithmic method intends to operate on the full scene. This means that high-resolution luminance information can not
be obtained. Even though tone mapping algorithms have the ability to operate over both full scene and local scene,
background knowledge is required. To resolve the shadow problem in digital aerial photogrammetry, shadow areas
should be recognized and corrected automatically without the loss of luminance information.
To this end, a practical shadow correction method using 12-bit real data acquired by DMC is investigated in this paper.
Although zoom lens has been widely accepted in vision system, the use of zoom lens was not general in close range
photogrammetry from the view point of instability by zooming. However, with the spread of consumer grade digital
cameras with integrated zoom lens, in particular long range such as ×35, digital close range photogrammetry using the
camera is enormously expected in various application fields. There is a large body of literature on calibration of zoom
lens. However, there is still problem for effective digital photogrammetry using the camera. The problem is practical
calibration model for zoom lens, in particular correction of misalignment which is caused by zoom setting.
In order to resolve instability of zoom lens, and practical use of digital close range photogrammetry using zoom lens, a
new calibration model is proposed in this paper based on correction of zoom lens misalignment. Furthermore, in order to
evaluate the proposed calibration model for zoom lens, calibration tests were conducted using 5 kinds of consumer grade
digital camera with integrated zoom lens (×3~5), 3 kinds of long range consumer grade digital camera (×12~30) and
digital SLR camera with zoom lens (×11).
Recently, pixel numbers and functions of consumer grade digital camera are amazingly increasing by modern
semiconductor and digital technology, and there are many low-priced consumer grade digital cameras which have more
than 10 mega pixels on the market in Japan. In these circumstances, digital photogrammetry using consumer grade
cameras is enormously expected in various application fields.
There is a large body of literature on calibration of consumer grade digital cameras and circular target location. Target
location with subpixel accuracy had been investigated as a star tracker issue, and many target location algorithms have
been carried out. It is widely accepted that the least squares models with ellipse fitting is the most accurate algorithm.
However, there are still problems for efficient digital close range photogrammetry. These problems are reconfirmation of
the target location algorithms with subpixel accuracy for consumer grade digital cameras, relationship between number
of edge points along target boundary and accuracy, and an indicator for estimating the accuracy of normal digital close
range photogrammetry using consumer grade cameras. With this motive, an empirical testing of several algorithms for
target location with subpixel accuracy and an indicator for estimating the accuracy are investigated in this paper using
real data which were acquired indoors using 7 consumer grade digital cameras which have 7.2 mega pixels to 14.7 mega
Recently, the documentation and visualization of various cultural heritages have been receiving attention, and a small
Buddha such as less than 10 cm tall which was stored in the womb of Buddha is also included in cultural heritages.
Zoom lenses are generally used to document these small objects and thus conserve the cultural heritage. However, there
exist certain issues pertaining to the use of zoom lenses for such digital documentation. These issues include image
sharpness and distortions that occur with changes in focal length setting, and in particular, the depth of field is issue from
application standpoint such as documentation of the small cultural heritage. On the other hand, macro lenses can be used
to capture sharp images of small objects from the view point of working distance, and its depth of field is related to the
aperture of the camera.
In order to evaluate the effectiveness of macro lenses in digital close range photogrammetry, macro lens and zoom lens
were mounted on a digital single lens reflex camera (Canon EOS20D, 8.2 Mega pixels). This paper deals in a first part
with comparative evaluations for both lenses with respect to their lens distortion, imaging mode, and calibration aspects.
The results indicated that macro lenses were more suitable for digital close range photogrammetry. Calibration tests are
performed to demonstrate the effectiveness and practicability of macro lens in close range photogrammetic applications.
Airborne laser scanner is widely adopted for city modeling, DTM (Digital Terrain Model) generation, monitoring
electrical power lines and detection of forest areas. In generally, airborne laser scanning enables to acquire point cloud
3D data for surface of the ground or objects using multiple return pulses (first, last and other pulse). Filtering for
distinguish on- and off-terrain points from point cloud 3D data which are collected by airborne laser scanner was issue,
and various filtering methods have been developing for generating DTM using point cloud 3D data.
Waveform information (range, pulse amplitude, pulse width) which is corrected by resent laser scanner system has been
receiving more attention for improvement of classifying the point cloud data into on- and off-terrain points. Waveform
information has ability to classify the point cloud data, however, robust filtering for distinguish on- and off-terrain points
is still issue. The main problem is robust extraction of the deepest points which shows ground surface. As many filtering
and classifying methods for robust extraction of the deepest points were proposed including waveform information, the
problem reaches extraction of the last pulse since the last pulse show the deepest points.
With this motive, filtering and classifying approach for DTM generation in forested area using multiple return pulses
instead of waveform information are investigated in this paper.
The authors have been concentrating on developing convenient 3D measurement methods using consumer grade digital
cameras, and it was concluded that consumer grade digital cameras are expected to become a useful photogrammetric
device for the various close range application fields. On the other hand, mobile phone cameras which have 10 mega
pixels were appeared on the market in Japan. In these circumstances, we are faced with alternative epoch-making
problem whether mobile phone cameras are able to take the place of consumer grade digital cameras in close range
In order to evaluate potentials of mobile phone cameras in close range photogrammetry, comparative evaluation between
mobile phone cameras and consumer grade digital cameras are investigated in this paper with respect to lens distortion,
reliability, stability and robustness. The calibration tests for 16 mobile phone cameras and 50 consumer grade digital
cameras were conducted indoors using test target. Furthermore, practability of mobile phone camera for close range
photogrammetry was evaluated outdoors. This paper presents that mobile phone cameras have ability to take the place of
consumer grade digital cameras, and develop the market in digital photogrammetric fields.
Recently, a laser scanner has been receiving more attention as a useful tool for real-time 3D data acquisition, and various applications such as city modeling, DTM generation and 3D modeling of cultural heritage were proposed. However, robust filtering for distinguish on- and off-terrain points from point cloud 3D data collected by airborne laser scanner is still issues. In particular, filtering of point cloud 3D data collected by terrestrial laser scanner has more severe problems caused by many occlusion parts, windows, few the deepest points, wall of buildings and so on.
In order to perform 3D texture modeling of cultural heritage using terrestrial laser ranging data, texture modeling method are investigated in this paper, and proposed filtering method is based on flatness within 30*30cm. Flatness area (ground surface, wall of structures, etc.) and non-flatness area (trees, bushes, etc.) is classified using measurement result of many target., and non-flatness areas are interpolated using morphological procedure.
The filtering method shows very robust result, and the most remarkable point of this filtering method is its ability to obtain break-lines which give important information for 3D modeling since 3D model of historical structure are consists of flatness areas (e.g. roof, wall, pillar). Therefore, surface patch of 3D model is identified by extracting a flatness area which is surrounded by break-line, and 3D model for the patch is generated using point cloud 3D data along the frame of the patch.
Furthermore, curve points for surface patch are detected from break-line, and a surface patch is generated in automatically step-by-step, texture modeling will be done with the surface patch and digital image.
Therefore, automatic detection of the curve point, which is necessary for model making, is very difficult. Because, break-line includes a lot of small curve points.
In this paper, we particularly watched this problem and carried out promotion of efficiency of model making by developing a solution method.
With these processes, efficient 3D representation using textured model is performed without any processes.
This paper presents 3D textured modeling method for historical structure using terrestrial laser ranging data and break-line by flatness evaluation, detection method of curve point using break-line.
3D city modeling from airborne imagery includes mainly two parts: (1) image processing procedures and (2) 3D modeling for man-made objects such as buildings, roads and other objects. Line extraction and stereo matching are usually utilized as an image processing procedures. However, there are some issues for automatic man-made object modeling. In particular, spatial data acquisition of buildings are important for reliable city modeling.
In these circumstances, this paper focuses on more efficient line matching method using Least-Median of Squares (LMedS). The LMedS have ability to calculate the trifocal tensor more accurately than least squares method, and the LMedS is able to remove inaccurate matched lines during the line matching procedure. Therefore, more accurate line matching can be performed, and more efficient city modeling was realized. This paper describes more efficient line matching method using LMedS, and investigates an adaptability of this system to city modeling.
3D city modeling from airborne imagery includes mainly two parts: (1) image processing procedures and (2) 3D modeling for man-made objects such as buildings, roads and other objects. Line or feature extraction and stereo matching are usually utilized as an image processing procedures, and geometrical data acquisition for man-made objects are performed. However, there are some issues for automatic or semi-automatic man-made object modeling. These problems include uncertainty within matching, extraction of man-made objects and spatial data acquisition. In particular, spatial data acquisition of buildings are important for reliable city modeling.
With this objective, this paper focuses especially on efficient and robust line matching method using optical flow, which enable an automatic building extraction since line gives important information for building extraction and satisfied results are depend on rigorous line extraction and matching. Furthermore, building extraction using morphological opening and 3D modeling for urban area are also investigated in this paper.
Recently, the number of pixels for consumer digital still camera are amazingly increasing by modern semiconductor and digital technology. The biggest pixels as a consumer digital camera were 0.8 millions at the 1996, and transmission techniques of image to PC had been received attention. Only 4 years later, in the 2000, there are 25 kinds of consumer pixel cameras on the market which have more than 3 million pixels in Japan. The functionary for transmission of image of PC is standardized, and the price is less than 1000 US dollars. IN these circumstances, it is expected that 3 million consumer digital still cameras will become useful tool in various real-time imaging fields, e.g. industry, machine and robot vision, archeology, architecture, construction management, and so on. With this objective, performance evaluation of 3 million consumer pixel cameras for digital photogrammetry were investigated in this paper.
In the compilation of archival records for archeological artifacts, true ortho-graphic drawings of these artifacts have to be drawn by the archaeologists themselves or part- timers, taking a great deal of time, labor and skill. For saving the labor, the authors have developed ortho projection system using CCD camera. 3D measurement system using ortho projection system are described in this paper. Finally, it demonstrates wireframe model for jomon-pottery by using this system.
The effectiveness of the real-time ortho projection and drawing system using a CCD camera and line lasers developed by the authors has been indicated. However, 3D visualization for archeological artifacts, such as wireframe model, surface model or texture model should be added to this system. There are some methods for performing a digital 3D modeling such as the range finder method. The most remarkable point of this system is its ability to get a real-time ortho projection image and a 3D model with one CCD camera.
In the compilation of archival records for archeological artifacts, true orthographic drawings of these artifacts have to be drawn by the archeologists themselves or part-timer, expending a great deal of time, labor, and skills. This paper describes the real time orthographic drawing system using a CCD camera. Finally, it demonstrates real time orthographic drawing results for Jomon pottery by using this system instead of the manual method which requires 3-4 hours.