Perspective Transformations - v8.0
© 2006-10 Martin Vicanek. 
First Release date: 19.03.2007 (Version 6)
Updates: 24.03.2008 (Version 7) 
	 17.04.2008 (Version 7.5) 
	 01.06.2008 (Version 7.6)
	 02.03.2009 (Version 7.8)
	 30.07.2009 (Version 7.9)
         13.05.2010 (Version 8.0)


DESCRIPTION:

This filter performs perspective transformations. Flat images can be tilted e.g. to create 3D compositions. Similarly, images taken at an angle can be rectified (e.g. tall buildings).


INSTALLATION:

Simply unzip "perspective.zip" and copy "perspective.8bf" to your "\Photoshop\Plug-Ins\" folder, or whichever plugin folder your host program uses. Load your program, open an image, go to the plugins menu and select the plugin.


64-BIT SYSTEMS:

If you are using Photoshop CS4 or CS5 on a 64-bit edition of Windows (XP, Vista or 7), then there are two editions of Photoshop installed on your computer: a 32-bit edition and a 64-bit edition. Perspective Transformations will run on the 32-bit Photoshop edition.

Please copy "perspective.8bf" to the 32-bit Plug-ins folder. Its default location is:
C:\Program Files (x86)\Adobe\Adobe Photoshop CS5 or CS4\Plug-Ins. 
The (x86) part is important!

To use Perspective Transformations, make sure you are running the 32-bit version of Photoshop! The default location is:
C:\Program Files (x86)\Adobe\Adobe Photoshop CS5 or CS4\Photoshop.exe.
Again, the (x86) part is important.


USAGE:

Image preview area: 
- Left-click and drag to set or move control points when Set control points is pressed. Use shift key to magnify region of interest for accurate positioning.
- Left-click and drag to set or move crop frame when set crop is pressed.
- Left-click and drag to tilt or pan the image otherwise.
- Right-click and drag to move the image.

Zoom control: 
Use + and - to zoom in and out.

"Preprocess" Section
--------------------
De-barrel:
Slider to compensate barrel or pincushion lens distortion before transforming the perspective.


"Control Points" Section
------------------------
Set control points to assist in rectifying perspective distortion.

Colored square: (new in Version 7.8)
Click to choose control points/lines color.

Vertical Lines/Parallelogram/Rectangle combobox:
Select compensation mode.

Vertical lines - draw two lines which are supposed to be vertical. 
The plugin will determine the values for the Rotate and the Tilt sliders. 
You can modify the Focal Length and Pan. 

Parallelogram - draw quadrilateral which will be transformed to a parallelogram.
The plugin will determine the Rotate, Pan and Tilt values.
You can modify the Focal Length.

Rectangle - draw quadrilateral which the plugin attempts to transform to a rectangle.
The plugin will determine the Focal Length, Rotate, Pan and Tilt values if possible,
otherwise it will switch to Parallelogram mode.

Set:
Set 4 control points in the image preview area. When done you can click and drag the points for fine adjustment. Use shift key to magnify region of interest for accurate positioning.

Snap: (new in Version 7.8)
When enabled control points set by the user will snap to the nearest high-contrast line. In rare cases, when the plugin fails to find a distinct straight line nearby, a yellow warning sign will be displayed below the Snap button. 

Apply:
Use control points to determine slider values for pesrpective compensation. Affected sliders will be highlighted.

Show:
Display or hide control points.

Reset:
Delete control points.


"Perspective" Section
---------------------
With this group of controls you specify a new viewing angle.

Modify/Rectify:
Radio buttons to choose between active (Modify) or passive (Rectify) transformations.

Display Reference Grid:
Tick to display a rectangular grid on the output image. This may be helpful for alignment.

Display Warped Grid:
Tick to display a rectangular grid on the input image. The grid will be warped along with the input image. Tick again to see only the grid without the input image.

Focal Length:
Set the focal length in mm, assuming the short side of the input image to be 24mm. 

Rotate:
Use this slider to rotate the image within its own plane.

Pan:
Rotate the image abut the vertical axis.

Tilt:
Rotate the image about the horizontal axis.

Reset:
Reset sliders to default positions.


"Crop" Section
--------------
In this section you can crop the warped image. Initially the warped image will be positioned automatically so no part will be cropped. However, as the warped image is no loger rectangular there will be black regions outside the image which you may want to remove.

Auto:
If pressed the plugin will find the largest possible rectangle while removing all black outside areas.

Set:
Use the mouse to define a rectangular crop region in the preview image. 

Apply:
Apply crop according to the selection.

Reset:
Discard the crop selection.


General Controls
----------------

Track:
Activate for instant preview update when moving sliders. Depending on your computer's performance you may want to disable this feature.

Cancel:
Exit the plugin without applying any effect.

OK:
Apply transformation and exit the plugin.

Reset All:
Reset all controls.

Dialog Size Grip (lower right corner):
Click and drag to resize the dialog window. 


-----------------------------

KNOWN BUGS:
none


FIXES AND IMPROVEMENTS:

Version 8.0
- Support for 16 bit/channel images 
- Support for grayscale images 

Version 7.9 
- Support for left-handed mouse settings

Version 7.8 
- Snap function for easier positioning of control lines
- Selectable control lines color
- Resizeable dialog
- An appropriate cursor is displayed when setting the Crop area

Version 7.6 
- Transparent background when the filter is applied to a layer (as in V6.0, thanks Elisa!) 

Version 7.5 
- New user-friendly Crop section replaces previous Positioning section
- Use shift key to magnify region of interest for accurate placement of control points
  (thanks to Dennie Kirtley for proposing this feature).

Version 7 
- Set control points in the preview image. The plugin evaluates these 
  control points and sets the slider values accordingly to rectify the image.
- Choose between various rectification modes
- De-barrel slider to compensate barrel or pincushion lens distortions. 
- Larger GUI and image preview
- Finer slider increments for higher precision
- Track option to enable/disable instant preview
- Automatic positioning works even with non-zero rotation
- Various minor bugs fixed


HOMEPAGE:
http://www.vicanek.de
