Utilização De Alvos Codificados Do Tipo Aruco Na Automação Do Processo De Calibração De Câmaras

Silva, Sérgio Leandro Alves Da; Tommaselli, Antônio Maria Garcia; Artero, Almir Olivette

doi:10.1590/s1982-21702014000300036

Cited by 15 publications

(15 citation statements)

References 13 publications

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“…With this scheme, 1024 values can be encoded. A Public software developed by Muñoz-Salinas (2012) was adapted to automatically perform the location, identification and accurate measurement of the four corners of the external crown of targets of the calibration field (Silva et al, 2012). With this software, most of the existing coded targets are automatically extracted.…”

Section: Experiments and Resultsmentioning

confidence: 99%

Using Vertical Panoramic Images to Record a Historic Cemetery

Tommaselli

Polidori

Hasegawa

et al. 2013

Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci.

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ABSTRACT:In 1919, during colonization of the West Region of São Paulo State, Brazil, the Ogassawara family built a cemetery and a school with donations received from the newspaper Osaka Mainichi Shimbum, in Osaka, Japan. The cemetery was closed by President Getúlio Vargas in 1942, during the Second World War. The architecture of the Japanese cemetery is a unique feature in Latin America. Even considering its historical and cultural relevance, there is a lack of geometric documentation about the location and features of the tombs and other buildings within the cemetery. As an alternative to provide detailed and fast georeferenced information about the a rea, it is proposed to use near vertical panoramic images taken with a digital camera with fisheye lens as the primary data followed by bundle adjustment and photogrammetric restitution. The aim of this paper is to present a feasibility study on the proposed technique with the assessment of the results with a strip of five panoramic images, taken over some graves in the Japanese cemetery. The results showed that a plant in a scale of 1:200 can be produced with photogrammetric restitution at a very low cost, when compared to topographic surveying or laser scanning. The paper will address the main advantages of this technique as well as its drawbacks, with quantitative analysis of the results achieved in this experiment.

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Section: Experiments and Resultsmentioning

confidence: 99%

Using Vertical Panoramic Images to Record a Historic Cemetery

Tommaselli

Polidori

Hasegawa

et al. 2013

Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci.

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“…These targets were automatically located in the images using a software adapted by Silva et al (2014) that identifies each target image coordinate with its respective ground coordinate.…”

Section: Performing Terrestrial Camera Self-calibrationmentioning

confidence: 99%

Exterior Orientation of Hyperspectral Frame Images Collected With Uav for Forest Applications

Berveglieri¹,

Tommaselli²

2016

Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci.

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ABSTRACT:This paper describes a preliminary study on the image orientation acquired by a hyperspectral frame camera for applications in small tropical forest areas with dense vegetation. Since access to the interior of forests is complicated and Ground Control Points (GCPs) are not available, this study conducts an assessment of the altimetry accuracy provided by control targets installed on one border of an image block, simulating it outside a forest. A lightweight Unmanned Aerial Vehicle (UAV) was equipped with a hyperspectral camera and a dual-frequency GNSS receiver to collect images at two flying strips covering a vegetation area. The assessment experiments were based on Bundle Block Adjustment (BBA) with images of two spectral bands (from two sensors) using several weighted constraints in the camera position. Trials with GCPs (presignalized targets) positioned only on one side of the image block were compared with trials using GCPs in the corners. Analyses were performed on altimetry discrepancies obtained from altimetry checkpoints. The results showed a discrepancy in Z coordinate of approximately 40 cm using the proposed technique, which is sufficient for applications in forests.

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“…Further specifications of the camera are shown in The fisheye camera was firstly calibrated in a 3D terrestrial calibration field composed of coded targets with Aruco format (Garrido-Jurado et al 2014), which were automatically located in the images using a software adapted by Silva et al (2014) to identify the targets in the field. Figure 4 shows an example of fisheye image with Aruco target corners extracted.…”

Section: Camera Calibrationmentioning

confidence: 99%

Tree Stem Reconstruction Using Vertical Fisheye Images: A Preliminary Study

Berveglieri

Tommaselli

2016

Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci.

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Commission V, WG V/4KEY WORDS : Dense Reconstruction, Fisheye, Image Rectification, Photogrammetry ABS TRACT:A preliminary study was conducted to assess a tree stem reconstruction technique with panoramic images taken with fisheye lenses. The concept is similar to the Structure from M otion (SfM ) technique, but the acquisition and data preparation rely on fisheye cameras to generate a vertical image sequence with height variations of the camera station. Each vertical image is rectified to four vertical planes, producing horizontal lateral views. The stems in the lateral view are rectified to the same scale in the image sequence to facilitate image matching. Using bundle adjustment, the stems are reconstructed, enabling later measurement and extraction of several attributes. The 3D reconstruction was performed with the proposed technique and compared with SfM . The preliminary results showed that the stems were correctly reconstructed by using the lateral virtual images generated from the vertical fisheye images and with the advantage of using fewer images and taken from one single station.

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Utilização De Alvos Codificados Do Tipo Aruco Na Automação Do Processo De Calibração De Câmaras

Cited by 15 publications

References 13 publications

Using Vertical Panoramic Images to Record a Historic Cemetery

Using Vertical Panoramic Images to Record a Historic Cemetery

Exterior Orientation of Hyperspectral Frame Images Collected With Uav for Forest Applications

Tree Stem Reconstruction Using Vertical Fisheye Images: A Preliminary Study

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