PanGazer logo PanGazer – image geography

Introduction

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Getting started

General settings

Saving views

Show location

Image geography

Overlays

Enhancements


Making panoramic images

Command line options

The gnomonic projection

Thanks

Image files can include ‘metadata’ (extra information, such as camera settings and location) as well as the image itself. PanGazer emphasises and simplifies the viewing and editing of geographical metadata values, including:

  • the location (latitude and longitude) of the camera
  • the elevation (metres or feet above sea level) of the camera
  • the compass bearing of the camera (the azimuth of the centre of the image, from True North)
  • the tilt of the camera (the pitch of the centre of the image, relative to the horizon).

If available, these values are shown as ‘static’ status at bottom-right of the view; see the General settings page for details.

In addition, if the bearing is known then compass points can be overlaid on the image to help give a sense of direction, and, similarly, if the tilt is known then tilt angles can be overlaid. See the Overlays page for details.

The geographical values can be edited by selecting Image → Image geography (or pressing the ‘g’ key) which will open a dialog box (described in detail below) that lets you view, modify, add, or delete relevant values for any image. In addition, the bearing can be set quickly for 360 images or spherical panoramas by using the Set North option on the pop-up menu (again, see the Overlays page for details) and Set horizon can be used to set the horizon for non-spherical images.

The geographical values for an image are held in the Exchangeable image file (Exif) data associated with an image; if you make any changes to the values you will be prompted to save the image before it is replaced or PanGazer is closed.

Image geography dialog

The Image geography dialog is used to view, modify, add, or delete any of the geographical values for any image. It is especially useful for adding missing values or adjusting existing values.  GPS location values can be inaccurate in rugged terrain or in urban situations, elevations are usually far less accurate than location data, and the camera bearing and tilt are often not available.

To open the geography dialog, select the Image → Image geography menu item or press the ‘g’ key. This will open the dialog and present the geographical values, for example:

PanGazer screenshot showing geography dialog

PanGazer screenshot showing geography dialog

You can edit any of the values directly; to delete a value clear the entry field (delete all the characters in it).

If you change or delete any value the Apply and Done buttons will be enabled (if all the values are good); the image will not be affected until you click one of those. To leave the dialog without applying changes, close it using its system menu or clicking the ‘X’.  If any change has been made you can also reset the values to the initial values (the values when the dialog was opened) by clicking on the Reset button.

The geographical values shown are:

Location: The image latitude and longitude. If the image location is known it will be shown here, formatted using the Coordinates format setting in effect when the dialog was opened. You can then modify the location as required. Many input formats are accepted; for details, see the Coordinate formats page.

Elevation: The elevation of of the camera in metres or feet above or below mean sea level. The units used in the dialog box are those first listed under Settings → Measurement settings (see the General settings page for details) when the dialog was opened; both metres and feet will be displayed in a view’s status if requested.

Bearing: The bearing (azimuth) of the image; that is, the true compass direction of the centre of the image. You can enter values from −360 through +360 degrees; PanGazer will normalize these to the range 0 through +360 degrees when displaying or saving.

As an aid while adjusting the bearing of an image, compass points are overlaid on the image when the Image geography dialog box is active and the bearing is valid, even if not normally shown (i.e., Settings → Overlays → Show compass points is unchecked).

Tilt: The tilt of the image; that is the vertical angle (pitch) of the centre of the image relative to the horizon (positive is above the horizon). You can enter values from −90 through +90 degrees. The tilt value is neither shown nor editable for spherical images because they always have a calculated horizon with the bottom edge of the image being at −90 degrees.

As an aid while adjusting the tilt of an image, tilt angles are overlaid on the image when the Image geography dialog box is active and the tilt value is valid, even if not normally shown (i.e., Settings → Overlays → Show tilt angles is unchecked).

PanGazer and these web pages were written by Mike Cowlishaw; Please send me any corrections, suggestions, etc.
All content © Mike Cowlishaw, 2014–2018, except where marked otherwise. All rights reserved. The pages here, and the PanGazer program, are for non-commercial use only.
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This page was last updated on 2018-12-12 by mfc.