PhotoWarp accepts several different types of images and panoramic media as sources, which can be unwarped into any of PhotoWarp's output formats. In this chapter we will discuss the source formats supported by PhotoWarp 2.0.
Do not use PhotoWarp to decode copyrighted materials without the author's permission. Copyright infringement is illegal. Don't steal panos.
The most common source format for many users is the 360 One VR source. This is a standard image file (TIFF, JPEG, etc.) photographed with a 360 One VR optical attachment. These images are often referred to as "donuts" because of their circular panoramic appearance.
PhotoWarp assumes that images are 360 One VR sources if they have the aspect ratio (pixel width / pixel height) of a traditional picture. Images photographed with most digital and film cameras produce either a 4:3 or 3:2 aspect ratio. You can also manually select the 360 One VR format by selecting it from the source format popup menu.
A solid target line denotes the edge of the mirror. A colored mask shows the area of the image that will be cropped from the output.
Adjust the color of the mask by choosing "Source → Mask Color..." Use the color panel to select the color and opacity. Results are shown immediately.
PhotoWarp 2.0 uses a target detection technique to automatically center for the target. Target detection is performed automatically when 360 One VR source images are added to a job. While target detection is running on an image, the target line pulsates until the target has been detected. Once finished, the line will change to one of several colors depending upon the confidence of the match:
Target detetion works best on properly framed 360 One VR images with good lighting. Properly framed
images have the mirror fill the frame vertically, without cropping the mirror.
Images too far out, too far in, and properly cropped.
The target mask can be dragged around manually to indicate the proper location of the mirror in the image. Start dragging the mask at any time; it isn't necessary to wait for the target to be detected. The target line will turn black to indicate a custom selection. Dragging on the line itself will change its diameter.
A pan knob appears on the image which denotes the center of the view of any generated panorama files. Click and drag on this knob to change the initial viewing angle for generated panoramas.
Click on the Settings...
button to show additional settings for 360 One VR images.
Shooting Direction
provides for images where the camera is shot down onto the optic (e.g., when resting the optic on a table). This will flip the resulting panorama so it appears correctly.
Target Selection
reflects the use of target detection on this image. Automatic
uses the detected position for the target. Manual is used to override this value. The detected location can be restored after dragging the target by clicking "Automatic".
The Apply to All
button is useful mainly to apply the same manual target position to a series of images in a job at once. Position the target for any source image. Then click on "Apply to All". The remaining 360 One VR sources in the job will turn off target detection and set the same position as the current source.
PhotoWarp accepts panoramic images using cylindrical or spherical (equirectangular) projections as well. These might have been generated by another program (perhaps a stitching program, or an image generated by a rotating slit device), or by PhotoWarp itself as the result of a previously unwarped source.
Images that are very wide (greater than 3:2 aspect ratio) are assumed to have a cylindrical projection. If the aspect ratio is exactly 2:1, the image is assumed to be a full spherical panorama. Further, very tall images are assumed to be vertical cylinders, or cylindrical panoramas rotated 90 degrees to the left. Additionally, PhotoWarp identifies TIFF and JPEG images generated by PhotoWarp 2 automatically, along with the appropriate settings.
With either of these source formats, a horizon line appears over the image. This line denotes a tilt angle of 0 degrees in the image. This should properly appear just above the actual horizon of the image. Assuming the image is shot at eye level, drag the horizon line to align with an object at the same height as the camera in the original shot. This is important to ensure the resulting panorama will not be distorted when unwarping. With cylindrical or spherical images generated by PhotoWarp, the initial position is fixed and the proper position extracted from the file itself.
Like other sources, the pan knob will appear on top of the horizon line to indicate the initial view of resulting panoramas. Drag this knob left or right to choose an appropriate view.
Click on the Settings...
button to reveal numerical settings for the source.
Normally the pan range for a cylindrical or spherical input image is from 0 to 360 degrees. For partial panoramas, set these numbers appopriately.
Tilt settings allow the lower and upper tilt bounds to be specified explicitly. These are set graphically by dragging the horizon line, but for precise settings or for non-square pixels, values can be entered numerically.
Vertical cylinders are rotated for display in PhotoWarp to appear normally. If an image appears rotated, toggle the orientation setting so it appears correctly. The orientation setting appears only for cylindrical images, not spherical.
PhotoWarp also accepts cylindrical QuickTime VR movies as a source. These sources will appear similarly to a cylindrical image source, but all the parameters are encoded within the movie. PhotoWarp can read both horizontal and vertical VRs that use QTVR 2.0 encoding. Some very old panoramas that use the QTVR 1.0 encoding cannot be read.
QuickTime VR cylinder sources can be useful to convert a collection of QuickTime VR movies for other viewers; for instance, to provide a Java version of the panorama for display.
Whenever possible, use the original image as a source rather than a QuickTime VR. QuickTime VRs are typically compressed for delivery. Unwarping will degrade image quality further when re-compressed by PhotoWarp.
Like the cylindrical image source, a pan knob appears on top of the image to allow selection of the initial view for generated panoramas. Drag the knob to choose a suitable view.
No settings can be changed on a QuickTime VR panorama since all the important details are encoded within the movie. The Settings pane displays the pan and tilt constraints defined by the panorama for reference.