Rio de Janeiro State University | E-Foto ProjectInterior Orientation Module Tutorial for E-Foto Project Integrated VersionAuthor: Patrícia Farias Reolon Coordination: Jorge Luís Nunes e Silva Brito. Revision: Jorge Luís Nunes e Silva Brito and João Araújo Ribeiro.

Interior Orientation Module TutorialE-Foto Free Software

Preface

The Interior Orientation is the process whereby one can recover the digital image’s

coordinate system reference back to photogrammetric camera’s metric coordinate system.

This is possible through measuring the image’s fiducial marks, generally available in those

taken with film cameras (analog cameras). For a digitized image, the fiducial marks

measurement allows to correlate the pixels’ position (column and line) in such image with

the millimeters in the camera’s Cartesian system, where axes cross over the optic axe

projection on the image plane (principal point).

This tutorial aims helping on the Interior Orientation (I.O.) photogrammetric project stage,

guiding its execution in a step-by-step way from a project previously saved in the projects

management module.

Introduction

Starting the E-Foto Free Software the start screen is shown (Picture 1). On main menu there are the options Project, Execute and Help. To do the Interior Orientation, we must its module with an already saved set of data (the projects’ management module – new project setup stage, which was fed with the photogrammetric camera calibration certificate). If you do not know how to create a photogrammetric project in this integrated version of E-Foto, we strongly suggest the specific tutorial reading.

Beginning the example on how to get the Interior Orientation from previously saved data set, select Project menu item as seen in Picture 1.

Picture 1 – E-Foto integrated version start screen

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Starting the Interior Orientation

Step 1: On Project menu select the option Load File and a saved projects’ list will take place. If the desired project is not listed you can browse the computer to find and select it.

Select then the Project as in Picture 2.

Picture 2 –Project Header window to load a saved project.

Step 2: After clicking Button “Open” the window as in Picture 3 will be shown. For starting I. O. for first image, select item Execute and then Interior Orientation. A smaller window allows selecting the image for which the fiducial marks measurement will be done. After selecting the image, click OK as shows Picture 4.

Note: If there is a warning message informing that image’s reference is lost, it’s necessary to point to image file’s path for them to get referenced again. For so, click Project Header on the tree structure in Open Project, and right Bellow an image list will appear. Click an image once a time and go to workspace Image. Click button Edit then button Select Image will be enabled. It makes possible to navigate by directories and point each image’s correct path. Remember to select “OK” to finish the setting.

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Picture 3 – Interior Orientation starting screen.

Picture 4 – Starting Interior Orientation to image 1 (image 016).

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Step 3: Now we need to identify the fiducial marks on the image according to the coordinates contained on the “Fiducial Marks Coordinates” table, as in Picture 5.

Picture 5 – Image fiducial marks identification screen.

Step 4: To identify the image fiducial marks, remember to consider that point (0,0) corresponds to the image center. We start from the first mark, in this example, located at the right side of image. To do the measurement, we must use the Zoom tool, as in Picture 6.

Note: Observe that on the first line of Fiducial Marks Coordinates table, the values are registered and cursor jumps to the immediate lower line. If measurement needs to be redone, simply get back to the corresponding line and click image in the correct position. The mark will be measured once again and table will be updated.

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Picture 6 – First fiducial mark zoom in image 016.

Step 5: Now click button Set Mark and then over the first fiducial mark as shows Picture 7.

Picture 7 – Zoom on the image 016 first fiducial mark already measured.

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Step 6: Repeat the process for the second image. To get the image back to its original view size, click button FitView. Zoom in the second mark to better view it. From the information on the table, the second mark is that in image’s central left side. Clicking button Set Mark then on the mark, it will be measured and updated on the table. Cursor jumps to third line, as shown in Picture 8.

Picture 8 – Zoom on the image 016 second mark after being measured.

Step 7: Repeat the process described in steps 4 to 6 to third mark. To get the image back to its original view size click button FitView. Zoom in the third mark to better view it. From the information on the Fiducial Marks Coordinates table, the third mark is that located on the image’s upper center side. Clicking button Set Mark and then on the mark it will be measured and updated on the table. Cursor jumps to fourth line – the last one – as shown in Picture 9.

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Picture 9 – Zoom on the image 016 third mark after being measured.

Step 8: We have finished then the process for the fourth mark. Next step is to return the image to its original view size. Click button FitView. Zoom in the fourth mark to better view it. From the information on the Fiducial Marks Coordinates table, the fourth mark is that located on the image’s lower center side. Clicking button Set Mark and then on the mark it will be measured and updated on the table as shown in Picture 10.

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Picture 10 – Zoom on the image 016 fourth mark after being measured.

Step 9: We will now execute Interior Orientation parameters calculation for this image. Select menu item Execute and option Interior Orientation or directly click button Interior Orientation, as show the following Pictures 11, 12 and 13.

Picture 11 – Interior Orientation results screen (adjusted transformation parameters Xa matrix).

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Picture 12 – Interior Orientation results screen (observations La matrix).

Picture 13 – Interior Orientation results screen (accuracy V matrix) and a posteriori unit weight variance (squared zero sigma).

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Step 10: After checking the results, in order to I. O. to be registered on the photogrammetric project we must confirm clicking button Accept. Executing such operation we can close the I. O. module and return to main workspace. On main workspace select item Project then option Save File. Doing so, we save this process results on the project. As the process for one image is finished we must repeat it to the other images contained on the photogrammetric project. In this example, repeat steps 2 to 8 for image 017 and to image 018 as well. Remember to save the file, preferably for each image you do the Interior Orientation, or at the end of whole process if you prefer to save it at once. Once saved, go to workspace region that shows the Open Project tree structure, click on Images and just beside the information on which images the Interior Orientation were done will

appear, signed with the check mark as in Picture 14.

Picture 14 – Operation history on the photogrammetric Project images.

Step 11 If you want to view the results again, select item Execute, Interior Orientation and click button View Report and the results’ table will be shown once again, as shown in Pictures 11, 12 e 13 early presented.

- End of tutorial -

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Rio de Janeiro State University | E-Foto ProjectInterior Orientation Module TutorialE-Foto Free SoftwarePrefaceIntroductionStarting the E-Foto Free Software the start screen is shown (Picture 1). On main menu there are the options Project, Execute and Help. To do the Interior Orientation, we must its module with an already saved set of data (the projects’ management module – new project setup stage, which was fed with the photogrammetric camera calibration certificate). If you do not know how to create a photogrammetric project in this integrated version of E-Foto, we strongly suggest the specific tutorial reading.Beginning the example on how to get the Interior Orientation from previously saved data set, select Project menu item as seen in Picture 1.Step 1: On Project menu select the option Load File and a saved projects’ list will take place. If the desired project is not listed you can browse the computer to find and select it.Select then the Project as in Picture 2.Step 2: After clicking Button “Open” the window as in Picture 3 will be shown. For starting I. O. for first image, select item Execute and then Interior Orientation. A smaller window allows selecting the image for which the fiducial marks measurement will be done. After selecting the image, click OK as shows Picture 4.