Focusing the Tilt Shift Lens
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Visual Tilt Estimation for Planar-Motion Methods in Indoor Mobile Robots
robotics Article Visual Tilt Estimation for Planar-Motion Methods in Indoor Mobile Robots David Fleer Computer Engineering Group, Faculty of Technology, Bielefeld University, D-33594 Bielefeld, Germany; dfl[email protected]; Tel.: +49-521-106-5279 Received: 22 September 2017; Accepted: 28 October 2017; Published: date Abstract: Visual methods have many applications in mobile robotics problems, such as localization, navigation, and mapping. Some methods require that the robot moves in a plane without tilting. This planar-motion assumption simplifies the problem, and can lead to improved results. However, tilting the robot violates this assumption, and may cause planar-motion methods to fail. Such a tilt should therefore be corrected. In this work, we estimate a robot’s tilt relative to a ground plane from individual panoramic images. This estimate is based on the vanishing point of vertical elements, which commonly occur in indoor environments. We test the quality of two methods on images from several environments: An image-space method exploits several approximations to detect the vanishing point in a panoramic fisheye image. The vector-consensus method uses a calibrated camera model to solve the tilt-estimation problem in 3D space. In addition, we measure the time required on desktop and embedded systems. We previously studied visual pose-estimation for a domestic robot, including the effect of tilts. We use these earlier results to establish meaningful standards for the estimation error and time. Overall, we find the methods to be accurate and fast enough for real-time use on embedded systems. However, the tilt-estimation error increases markedly in environments containing relatively few vertical edges. -
Estimation and Correction of the Distortion in Forensic Image Due to Rotation of the Photo Camera
Master Thesis Electrical Engineering February 2018 Master Thesis Electrical Engineering with emphasis on Signal Processing February 2018 Estimation and Correction of the Distortion in Forensic Image due to Rotation of the Photo Camera Sathwika Bavikadi Venkata Bharath Botta Department of Applied Signal Processing Blekinge Institute of Technology SE–371 79 Karlskrona, Sweden This thesis is submitted to the Department of Applied Signal Processing at Blekinge Institute of Technology in partial fulfillment of the requirements for the degree of Master of Science in Electrical Engineering with Emphasis on Signal Processing. Contact Information: Author(s): Sathwika Bavikadi E-mail: [email protected] Venkata Bharath Botta E-mail: [email protected] Supervisor: Irina Gertsovich University Examiner: Dr. Sven Johansson Department of Applied Signal Processing Internet : www.bth.se Blekinge Institute of Technology Phone : +46 455 38 50 00 SE–371 79 Karlskrona, Sweden Fax : +46 455 38 50 57 Abstract Images, unlike text, represent an effective and natural communica- tion media for humans, due to their immediacy and the easy way to understand the image content. Shape recognition and pattern recog- nition are one of the most important tasks in the image processing. Crime scene photographs should always be in focus and there should be always be a ruler be present, this will allow the investigators the ability to resize the image to accurately reconstruct the scene. There- fore, the camera must be on a grounded platform such as tripod. Due to the rotation of the camera around the camera center there exist the distortion in the image which must be minimized. -
Video Tripod Head
thank you for choosing magnus. One (1) year limited warranty Congratulations on your purchase of the VPH-20 This MAGNUS product is warranted to the original purchaser Video Pan Head by Magnus. to be free from defects in materials and workmanship All Magnus Video Heads are designed to balance under normal consumer use for a period of one (1) year features professionals want with the affordability they from the original purchase date or thirty (30) days after need. They’re durable enough to provide many years replacement, whichever occurs later. The warranty provider’s of trouble-free service and enjoyment. Please carefully responsibility with respect to this limited warranty shall be read these instructions before setting up and using limited solely to repair or replacement, at the provider’s your Video Pan Head. discretion, of any product that fails during normal use of this product in its intended manner and in its intended VPH-20 Box Contents environment. Inoperability of the product or part(s) shall be determined by the warranty provider. If the product has • VPH-20 Video Pan Head Owner’s been discontinued, the warranty provider reserves the right • 3/8” and ¼”-20 reducing bushing to replace it with a model of equivalent quality and function. manual This warranty does not cover damage or defect caused by misuse, • Quick-release plate neglect, accident, alteration, abuse, improper installation or maintenance. EXCEPT AS PROVIDED HEREIN, THE WARRANTY Key Features PROVIDER MAKES NEITHER ANY EXPRESS WARRANTIES NOR ANY IMPLIED WARRANTIES, INCLUDING BUT NOT LIMITED Tilt-Tension Adjustment Knob TO ANY IMPLIED WARRANTY OF MERCHANTABILITY Tilt Lock OR FITNESS FOR A PARTICULAR PURPOSE. -
Shooting the Stars: an Intro to Astrophotography
Temperatures are dropping and fall has fallen, bringing with it colorful leaves changing hues, football season and an anticipation of the holidays ahead. This month’s issue includes what you’ll need to photograph fall sporting events as well as tips for shooting the stars. We know scary season is coming so we’ve included some of our favorite Halloween picture-taking tips. We also let you know the one thing you should check before entering a photo contest. Want to know about the legal suit that focused on a monkey taking a selfie? And how it ended? It’s in here! Remember that we’re here for you, so please call, email or visit us on Facebook. We’re happy to answer any photography questions and we'll make sure that you get the best camera or accessory for your particular needs and budget. Shooting the Stars: An Intro to Astrophotography Do you enjoy getting lost in thought the stars, so feel free to adjust your settings while staring at the nighttime sky? Turns accordingly. You will want to shoot at out that you aren’t alone. Not only is different settings and using auto mode won’t an evening enjoying nature’s light work well in this situation. Also, check the show a wonderful hobby, it has also weather as clouds and overcast skies will fostered an interest in photographing keep the nighttime jewels hidden from sight. shooting star trails and other Need a couple of basics to get started evening star shows. in Astrophotography? The term ‘astrophotography’ simply means photographing Our quality ProMaster remotes anything not on Earth, but rather, in space. -
The General Idea Behind Editing in Narrative Film Is the Coordination of One Shot with Another in Order to Create a Coherent, Artistically Pleasing, Meaningful Whole
Chapter 4: Editing Film 125: The Textbook © Lynne Lerych The general idea behind editing in narrative film is the coordination of one shot with another in order to create a coherent, artistically pleasing, meaningful whole. The system of editing employed in narrative film is called continuity editing – its purpose is to create and provide efficient, functional transitions. Sounds simple enough, right?1 Yeah, no. It’s not really that simple. These three desired qualities of narrative film editing – coherence, artistry, and meaning – are not easy to achieve, especially when you consider what the film editor begins with. The typical shooting phase of a typical two-hour narrative feature film lasts about eight weeks. During that time, the cinematography team may record anywhere from 20 or 30 hours of film on the relatively low end – up to the 240 hours of film that James Cameron and his cinematographer, Russell Carpenter, shot for Titanic – which eventually weighed in at 3 hours and 14 minutes by the time it reached theatres. Most filmmakers will shoot somewhere in between these extremes. No matter how you look at it, though, the editor knows from the outset that in all likelihood less than ten percent of the film shot will make its way into the final product. As if the sheer weight of the available footage weren’t enough, there is the reality that most scenes in feature films are shot out of sequence – in other words, they are typically shot in neither the chronological order of the story nor the temporal order of the film. -
Macro Photography Camera Richard J
Evaluating A Macro Photography Camera Richard J. Nelson Introduction My company, AMF, purchased a general-purpose digital camera five years ago, the Sony Mavica, model MVC-FD83. The digital capability and floppy disc drive media proved very practical for general documentation purposes. The floppy discs made it convenient for any employee to work with the images. After about 20,000+ images the floppy drive wore out and a new camera was needed. Meanwhile I had personally purchased a Nikon Coolpix 995 camera with a 3.3 Megapixel resolution (a big improvement over the Sony Mavica 0.9 megapixel resolution) and close focus (2 cm) capability. This became a consideration for an AMF camera and we ordered one on eBay, which was lost by the USPS - it was insured. Earlier in 2005 I purchased a Sony T1 with a Magnify mode that featured a very close focus (1 cm) and 5- megapixel resolution. This camera has provided many of the images used on posters, reports, fundraiser book, procedures, and power point presentations, especially for the BPB project. The ability to produce a large image of a very small object has proved very useful for our engineering and publicity projects. The Sony T1 works especially well as a general documentation camera for me because I always have it with me, I have extra memory cards, 1 GB total for about 500 images, and 2 extra batteries for any photo shoot requirements. All of this fits in my shirt pocket and is with me 24/7. The T1 has two serious limitations. The first is sharpness with magnification, and the second is working distance for lighting. -
Depth of Field PDF Only
Depth of Field for Digital Images Robin D. Myers Better Light, Inc. In the days before digital images, before the advent of roll film, photography was accomplished with photosensitive emulsions spread on glass plates. After processing and drying the glass negative, it was contact printed onto photosensitive paper to produce the final print. The size of the final print was the same size as the negative. During this period some of the foundational work into the science of photography was performed. One of the concepts developed was the circle of confusion. Contact prints are usually small enough that they are normally viewed at a distance of approximately 250 millimeters (about 10 inches). At this distance the human eye can resolve a detail that occupies an angle of about 1 arc minute. The eye cannot see a difference between a blurred circle and a sharp edged circle that just fills this small angle at this viewing distance. The diameter of this circle is called the circle of confusion. Converting the diameter of this circle into a size measurement, we get about 0.1 millimeters. If we assume a standard print size of 8 by 10 inches (about 200 mm by 250 mm) and divide this by the circle of confusion then an 8x10 print would represent about 2000x2500 smallest discernible points. If these points are equated to their equivalence in digital pixels, then the resolution of a 8x10 print would be about 2000x2500 pixels or about 250 pixels per inch (100 pixels per centimeter). The circle of confusion used for 4x5 film has traditionally been that of a contact print viewed at the standard 250 mm viewing distance. -
Photography Tripod
Photography tripod Why do I Need a Tripod? http://www.bhphotovideo.com/explora/video/buying-guides/what-look-when-you-are-looking-video- tripod Tripod Tricks? http://vimeo.com/videoschool/lesson/110/tripod-tricks Extending and Locking the Tripod Legs When you have arrived at you location or on the set and are ready to set up your tripod I feel it best to extend the legs before you spread them into position. By doing it in this way you will get the legs into roughly the same length much easier than trying to eyeball the leg length. To extend the legs un-lock the first section of the tripod and extend the leg to the desired position and secure the lock into the closed position (figures 4, 5, and 6). Figure 4 Figure 5 Figure 6 Then press the locking tab back into the closed position (figure 6). Repeat these steps for the remaining legs. Would be good to point out that "proper" way of opening tripods is top down, so that the thinnest leg section is the last to be used Fine tuning the camera height can be done with the center column, once you have established the desired height Loosen the locking knob on the center column and lift the camera into position (figures 7 and 8). Figure 7 Figure 8 With the camera in the position you want re-tighten the locking knob to secure the column into position (figure 9). Bear in mind that the center column is the part of the tripod most subject to torsion and vibration - many professional photographers choose never to use it at all. -
Depth of Focus (DOF)
Erect Image Depth of Focus (DOF) unit: mm Also known as ‘depth of field’, this is the distance (measured in the An image in which the orientations of left, right, top, bottom and direction of the optical axis) between the two planes which define the moving directions are the same as those of a workpiece on the limits of acceptable image sharpness when the microscope is focused workstage. PG on an object. As the numerical aperture (NA) increases, the depth of 46 focus becomes shallower, as shown by the expression below: λ DOF = λ = 0.55µm is often used as the reference wavelength 2·(NA)2 Field number (FN), real field of view, and monitor display magnification unit: mm Example: For an M Plan Apo 100X lens (NA = 0.7) The depth of focus of this objective is The observation range of the sample surface is determined by the diameter of the eyepiece’s field stop. The value of this diameter in 0.55µm = 0.6µm 2 x 0.72 millimeters is called the field number (FN). In contrast, the real field of view is the range on the workpiece surface when actually magnified and observed with the objective lens. Bright-field Illumination and Dark-field Illumination The real field of view can be calculated with the following formula: In brightfield illumination a full cone of light is focused by the objective on the specimen surface. This is the normal mode of viewing with an (1) The range of the workpiece that can be observed with the optical microscope. With darkfield illumination, the inner area of the microscope (diameter) light cone is blocked so that the surface is only illuminated by light FN of eyepiece Real field of view = from an oblique angle. -
Surface Tilt (The Direction of Slant): a Neglected Psychophysical Variable
Perception & Psychophysics 1983,33 (3),241-250 Surface tilt (the direction of slant): A neglected psychophysical variable KENT A. STEVENS Massachusetts InstituteofTechnology, Cambridge, Massachusetts Surface slant (the angle between the line of sight and the surface normal) is an important psy chophysical variable. However, slant angle captures only one of the two degrees of freedom of surface orientation, the other being the direction of slant. Slant direction, measured in the image plane, coincides with the direction of the gradient of distance from viewer to surface and, equivalently, with the direction the surface normal would point if projected onto the image plane. Since slant direction may be quantified by the tilt of the projected normal (which ranges over 360 deg in the frontal plane), it is referred to here as surfacetilt. (Note that slant angle is mea sured perpendicular to the image plane, whereas tilt angle is measured in the image plane.) Com pared with slant angle's popularity as a psychophysical variable, the attention paid to surface tilt seems undeservedly scant. Experiments that demonstrate a technique for measuring ap parent surface tilt are reported. The experimental stimuli were oblique crosses and parallelo grams, which suggest oriented planes in SoD. The apparent tilt of the plane might beprobed by orienting a needle in SoD so as to appear normal, projecting the normal onto the image plane, and measuring its direction (e.g., relative to the horizontal). It is shown to be preferable, how ever, to merely rotate a line segment in 2-D, superimposed on the display, until it appears nor mal to the perceived surface. -
Macro Photography
MACRO PHOTOGRAPHY Dave Bremner February 21,2019 What is it? It is extreme close- up photography, usually of very small subjects and living organisms like insects, in which the size of the subject in the photograph is greater than life size (though macrophotography technic ally refers to the art of making very large photographs) (Wikipedia) Think small. Size matters in reverse! You want to make something that is small, larger than life size if you can. What is needed for Macro: The following is a list of gear, ideas, and means of achieving MACRO 1) Camera (obvious) DSLR, mirrorless ILC, or compact camera, or cell phone 2) Macro lens 1:1 magnification if you have one, or compact camera with macro setting, or a lens with macro setting depicted usually with a flower either on the camera or on the lens. The lower the ratio the better ie 1:2,1:3,1:4 etc. 3) Tripod and remote or knowledge of using the timer mode on your camera to prevent camera shake during the exposure. 4) You want to get as close to the subject/object that you want to shoot and achieve optimal focus and DOF (depth of field for the articles in the image that you want to display to your taste.) 5) Do you want abstract , or accurate recognizable depiction? Most mundane everyday things (insects, snowflakes , water drops can be almost unrecognizable the larger the final image can be made). Try shooting something like a cheese grater, or cutlery close up to obtain something abstract. Cheese Grater Cutlery and lens ball 6) PATIENCE: This is something I do not have a lot of and you may find yourself expending yours trying to obtain the shot you want in the proper light and composition. -
Wide Shot (Or Establishing Shot) Medium Shot Close-Up Extreme
Definitions: Wide Shot (or Establishing Shot) Medium Shot Close-up Extreme Close-up Pan –Right or left movement of the camera Tilt –Up or down movement of the camera Zoom –Change in focal length (magnification) of the lens V/O –Voice-over, narration not synchronized with video SOT –Sound on Tape, Interview audio synchronized with video B-Roll -Refers to the earlier days of film when you had two rolls of film – A and B – and you had to edit them together. A-roll is the main subject of your shot, with audio such as an interview with someone or SOT (Sound on Tape synchronized with the video). B-roll is the background video for your film, often just video over which you’ll lay an audio track (such as the person talking in the A-roll). Nat Sound (Wild Sound) –Natural sound recorded with B-Roll This is video that has some natural background noise – traffic on a street, birds chirping in a park, etc. This audio can add depth and impact to a two-dimensional video tape. 2-Shot –Shot of the interview subject and the person asking the questions Reverse Angle –Straight-on shot of the person asking the questions Use a Tripod Use a tripod to get a steady shot, particularly if you’re shooting something that is not moving or a formal interview. Shaky video, especially in close-ups, can cause the viewer to become dizzy, even nauseous. If you don’t have a tripod or you’re doing a shot where you’ll have to move quickly, then find something to steady your camera – i.e.