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PanGazer – getting started


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Getting started

General settings

Setting North

Saving views

Saving images

Sharing images

Image geography

Show image location


Spherical fills


Aspect ratio

Making panoramic images

The gnomonic projection

Coordinate formats

Keyboard shortcuts

Command line options

Saved metadata


Working with images

When you first start PanGazer a ‘starter’ panorama should be displayed; if you see a blank window, or wish to view a different image, try one of the following options.

  • select the Image → Open image menu item (or press the ‘p’ or ‘Ctrl-o’ key); this will open a dialog which will allow you to choose a panorama or other image file to be shown
  • drag one or more new images from File Explorer to a PanGazer window or icon (each new image will be opened in a new view window)
  • press the ‘PageDown’ or ‘PageUp’ key to show the next or prior image in the same directory as the current image, or press ‘Ctrl-PageDown’ or ‘Ctrl-PageUp’ to show the last or first image in that directory; the order in which images are shown is determined by Windows
  • select the Image → Open image in new window menu item to open an image without replacing the current image.

PanGazer will automatically detect if an image is a 360° or spherical panorama (even it it has no metadata – Exif, etc.) and will display it with the appropriate projection.  If available, metadata are used to set the initial viewpoint, etc., and in all cases the image will be centred and adjusted if necessary to fill the window.

PanGazer can load many types of images (JPEG, PNG, GIF, BMP, TIFF, etc.).  Note that, in general, JPEG images are often smaller (and therefore load faster) and also often include metadata such as the time of image capture and its location.

PanGazer can load very large images (up to the 65K×65K limit of JPEG images), provided that sufficient RAM memory is available. In most cases a progress bar will be shown if loading a JPEG image will take more than a second.

To save an image (e.g., after changing its geographical data) select the Image → Save image or the Image → Save image as ... menu item, or select the Image → Resize image and save as ... menu item; the latter opens a dialog that lets you change the size of the image before saving.  Saving will preserve metadata as possible, and also, if the image is spherical, will also save the current view parameters (bearing, tilt, etc.) in the saved file.

You can also save a part-spherical panorama (such as the starter image) as a full-sphere panorama for use in social media applications, etc.  For details, see the Saving images page and the Sharing images page

Alternatively you can fill a part-spherical panorama to make it full-sphere without saving it, to see how it looks, using the Image → Expand image to full sphere menu selection.  Similarly, nadir fill (or zenith fill) can be applied, e.g., to hide a tripod or person holding a 360° camera.  For more details, see the Spherical fill page.  Whenever a fill is applied, only data from your image are used (unlike “AI” fillers that use data from others’ images).

If the image is geotagged you can show its location on a map using Show location on satellite map (from the Image main menu or the right-click pop-up menu).  From the Image menu you can also show the location on a regular map, show it using an application such as MapGazer or Google Earth, or save it.  For details, see the Show location page.

To change the projection of a spherical or 360° image (to flat, so you can see the original image, or back to 360°), click the View → View image as a flat rectangle menu item or press underscore (if the image could not be 360° the menu item will be greyed).  When viewing as a flat rectangle you can treat it as a non-360° image (fit height, etc., see below).

To set or edit image geography (location, elevation, bearing, and tilt), select the Image → Image geography menu item (or press the ‘g’ key); see the Image Geography page for details.  Setting North is especially useful for spherical images.  If bearing or tilt are known, compass points and/or tilt angles can be overlaid on the image (see Overlays).

To make your own panorama image, see the Making panoramic images page for a couple of suggestions; there are also many other options.

Viewing images

When an image is opened it is shown as a view of the image in a window.

To change the viewpoint (when the image does not fill the window):

  • left click on the image (the cursor will change to a ‘hand’) and drag the image (dragging also works if you have a touch screen)
  • use the keyboard arrow keys.

To change the zoom (the magnification of the image):

  • move the cursor over the image and spin the mouse scroll wheel forward (to zoom in) or back (to zoom out); this will keep the point under the cursor at the same position in the window (press Ctrl while scrolling for a slower zoom in or out)
  • if you have a touch screen, the ‘pinch’ and ‘expand’ gestures should also zoom in or zoom out, centred on a point between your fingertips
  • right-click on the image and choose Zoom in or Zoom out on the pop-up menu, which will keep the clicked-on point static while zooming
  • use the ‘i’ or ‘o’ keys to zoom in or out while keeping the centre of the view fixed, or use the View → Zoom in or View → Zoom out menu items, which have the same effect; zooming out gives an increasingly wide-angle view but will also distort the view, especially in the corners
  • use ‘Shift-i’ or ‘Shift-o’ to zoom to the maximum or minimum zoom available.
  • select Zoom to 100% ratio from the View or pop-up menu; this will set the zoom so that a pel (pixel) of the image is sized to match a pel in the window (if possible; if the image is smaller than the window then it will be enlarged to fill the window).

See also the zoom level page for more detail about zoom levels.

To overlay compass points on a view to give a sense of direction, you may need to select Set North from the pop-up menu or use the Image Geography dialog – see the Setting North page for more details.  This is not necessary for images where North is known. 

Similarly, you can overlay a tilt and heading grid (or just angles) on any image.  See the Overlays page for details of these and other overlays.  Once you have set North or the horizon for an image, you may wish to use Image → Save image (or press the Ctrl-s key) to save the image so that next time it is loaded you will not need to re-do the settings.

You can toggle all overlays on and off (along with any status information shown) with the space bar.

To create an image from the current view, select the Save current view ... menu item from the View menu or from the pop-up menu (or press the ‘s’ key).  This will display a save dialog which lets you select the folder and enter the name for the new image. Unlike a screenshot, the new image will include the location, tilt, bearing, and focal length of the view, if available, as well as other data.  For more details, see Saving views.

Saved views do not include overlaid status information or overlays (they will be shown as appropriate if the saved image is opened later using PanGazer), and are saved in JPEG format.  After the image is saved it will be opened in a new window so you can check it.

To change the aspect ratio of the view, select View → Change view (window) aspect ratio (or press ‘a’); for more details, see the Aspect Ratio page.

To enhance the view of the image (change brightness, contrast, etc.), select the Enhance view menu item from the View or pop-up menus, or press the ‘e’ key; this will open the enhancements dialog.  For more details, see the Enhancements page.

To rotate or mirror an image that is not a 360° image, select Rotate/mirror image from the Image menu or from the pop-up menu, and then select the desired rotation or mirror operation. Necessarily this will change the image itself (so that status and metadata will be correct) but does not save it automatically.

To reset and centre the displayed image, select the Reset viewpoint menu item from the View menu or from the pop-up menu, or use the ‘r’ key.  This will position the centre of the image in the centre of the window at default zoom, or if the image is spherical and has a saved initial viewpoint, it will reset the viewpoint to that. 

For spherical images you can also select View → Change viewpoint to nadir (or press ‘n’) to centre the image at the nadir (−90°) view, select View → Change viewpoint to horizon (or press ‘h’) for a ‘level’ horizon (0°) view, or select View → Change viewpoint to zenith (or press ‘z’) for the zenith (+90°) view, as possible.

To use the Windows default viewer to view the image file, select View → View image with external (default) viewer (or press ‘x’).  This lets you use your preferred viewer to save the image in a different format, print it, etc.

Windows and window options

A PanGazer view is a window on the screen which displays an image. You can have more than one window open and each window can display a different (or the same) image with an independent viewpoint and/or zoom.

To add a new view window, select the View → Open new view or Window → Open new window menu item, or press the ‘v’ key. This shows the same view initially; in the new window you can then change the viewpoint or image (as described above).  You can add multiple windows and close (delete) them in any order; PanGazer will keep running until you close all open windows.  When you next start PanGazer the last view closed will be shown.

If an image is not a 360° panorama (or is being viewed as a flat image), you can fit the window to the image aspect ratio by selecting the Window → Fit window to aspect ratio menu item (or press ‘Ctrl-f’); PanGazer will attempt to change the window shape (keeping the same window area and staying within the bounds of the screen) to match the aspect ratio of the image.  Fit window to aspect ratio is also available on the pop-up menu.

You can also fit the image to the window (that is, make the image fill the height or width of the window, if possible) using Window → Fit height to window (‘Ctrl-h’) or Window → Fit width to window (‘Ctrl-w’), respectively.  These are also available on the pop-up menu.

To set a specific window aspect ratio, select Window → Change window aspect ratio (or press ‘a’); for more details, see the Aspect Ratio page.

The window options (under the Window menu item, with key options also on the pop-up menu) let you change the appearance of the window.  For example, to increase the amount of the window used for the image you can choose not to show the menu bar and/or title bar (the menu bar can be turned back on by right-clicking on the image to get the pop-up menu).

You can also ‘toggle’ a view window between Full screen and the view in a window by simply pressing the ‘Esc’ (Escape) key or the ‘F11’ key.  As usual, you can also maximize or minimize the window from the menu, or request that it be made ‘full-screen’.  When full-screen, only the image is shown (to then restore it to a normal window press the Esc (Escape) key or right-click on the image for the pop-up menu and choose Restore).

Settings, help, etc.

The Settings main menu lets you change settings that apply to all windows, including the status information to be displayed, direction and tilt overlays, measurement units, coordinate formats, initial load options, and diagnostic settings.  For details, please see the General settings page.

The Help main menu item lets you view these help pages locally (without using the Internet) or browse the PanGazer web pages (these are the same as the local pages if you are using the latest release).  In addition, the About PanGazer menu item confirms the version, origin, and .exe type of the application.

PanGazer may be started from the command line, or a script, with options to load one or more specified image files, etc.  It can also be started by clicking on an image type that has been associated with PanGazer.  For more details, please see the Command line help page.

PanGazer and these web pages were written by Mike Cowlishaw; Please send me any corrections, suggestions, etc.
All content Copyright © Mike Cowlishaw, 2014–2024, 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 2024-04-20 by mfc.