Rotate Color (a filter plug-in for Adobe Photoshop™ 3.0)
Free 68k version 1.0.0. Copyright 1996 Hugh Kawahara. All rights reserved.
§ 0. Quick Start (This section should be enough for most people.)
0.1 Distribution Policy (Yes, it's free!)
This 68k version is a freeware. Please read § 1 for the detail.
0.2 System Requirement
Any Macintosh computer running Adobe Photoshop™ 3.0.0 or later.
0.3 Installation
Move the entire "Rotate_Color" folder into the "Plug-ins" folder in your "Adobe Photoshop™"
folder. (Re)Start Photoshop. It will appear under the menu "Filter->colleen".
0.4 What It Does (Or just try it!)
It works on RGB images only. It rotates the color in the (3D) RGB space about the red, green,
blue, and hue axis. The origin of the rotation is the medium gray color. It also inverts the red,
green, and blue channels separately.
0.5 Usage
The usage of the four sliders for the rotations and three check boxes for the inversions
should be obvious. The plug-in creates a small thumb nail in the dialog box for quick preview
and a full size preview window over the original image window. Both previews are zoomable
and scrollable and the full size preview is resizable. The original image window still exists
behind the full size window. Use the "Glass" and "Hand" tools in the dialog box to zoom in/out
or scroll the previews. Double click to the toolbox fits/zoom-in the thumb nail preview.
Double click while holding down the option key fits/zoom-in the full size preview.
Hold down the option key and click on the "Cancel" button to reset all parameters.
0.6 How to Reach the Author
Please send comments, bug reports, etc. to <kawahara@leland.stanford.edu>.
Visit <http://www.stanford.edu/~kawahara> for updates.
User's Guide
This part is provided for completeness.
Some part may be too technical for some people.
Contents
1. Distribution Policy and Legal Stuff
2. System Requirement
3. Installation
4. What It Does
5. Usage
6. Misc. Notes
7. How to Reach the Author
8. Acknowledgment
§ 1. Distribution Policy and Legal Stuff
This particular version (the version is specified at the top of this document) is a freeware.
Other versions may not be.
You may distribute this software freely as far as no parts of the contents of the folder
"Rotate_Color", which includes this memo "Rotate_Color.doc" and the plug-in
"Rotate_Color.68k", are deleted or modified.
The author retains the copyright.
This software is provided "as is".
The author shall not be liable for any damages or losses caused by this software in any way.
§ 2. System Requirement
Hardware:
Macintosh computer with MC68020 processor or greater, including Power PC.
Math co-processor (FPU) is NOT required.
Software:
System 7.0 or greater.
Adobe Photoshop™ 3.0.0 or greater.
Since Photoshop 3.0 requires MC68020 and System 7.0, any Macintosh computers running Photoshop 3.0.0 or greater should be sufficient to run this plug-in.
It will not work with prior versions of Photoshop.
§ 3. Installation
Simply move, copy, or drag the entire "Rotate_Color" folder containing the plug-in and
this memo into the "Plug-ins" folder in your "Adobe Photoshop™" folder.
Quit Photoshop if it is running. Then (re)start Photoshop.
It will appear under the menu "Filter->colleen".
§ 4. What It Does
4.1 Image Mode
RGB images only.
4.2 What It Really Does
In the RGB model, colors are points in a three dimensional RGB space.
The plug-in arbitrary rotates this space about the mid-gray point (R = G = B = 50%).
To specify the rotation, the plug-in uses rotation angle about hue, red, green, and blue axis.
The hue axis starts at black (R = G = B = 0%) and ends at white (R = G = B = 100%).
The red axis starts at (R = 0%, G = B = 50%) and ends at (R = 100%, G = B = 50%), etc..
The rotations are counterclockwise assuming the RGB space is a right-handed coordinate.
In addition to the rotations, the plug-in inverts each color channel separately.
It applies the inversions first, then rotate the color about the axis in order of
hue, red, green, and blue.
Since the RGB space is cubic, it won't fit in the RGB space after the rotation.
The plug-in performs any contraction/expansion to/from the mid-gray point
necessary to fit into the final RGB space.
It preserves the mid-gray at any operation.
(Note: Rotation in a 3-D space only requires three rotations. Therefore, one of the four angles is superfluous.
However, if you use only three angles and requires completeness (such as Euler angles), they won't be symmetric,
i.e. the angles won't be directly connected to the color anymore. Also, two of the three inversions are superfluous.)
§ 5. Usage
5.1 Invocation
Simply choose "Rotate Color…" from the menu "Filter->colleen".
5.2 Adjusting the Rotation Angles
Use the sliders in the dialog window to adjust the rotation angles.
5.3 Inverting the Channels
Use the check-boxes in the dialog window. You can invert the channels separately.
5.4 Resetting the Rotation Angles and Inversions
Clicking the "Cancel" button while pressing the option key resets all parameters.
It sets all rotation angles to zero and un-checks all invert check boxes.
5.5 Previews
The plug-in creates two previews. One is a small thumb nail in the dialog box
and other one is a full size preview over the original image window.
The full size preview window is a separate window from the original image window.
To view the original image, just drag the preview window.
Both previews are zoomable and scrollable. The full size preview is resizable too.
Use the "Glass" tool to zoom-in/out the preview. Use the "Hand" tool or the scroll bars
to scroll the preview. Press the option key to zoom out. Press the command key to zoom in.
The maximum zoom-in ration is 1:1 at this moment.
To choose a tool, click the toolbox in the dialog window.
Double click the "Hand" tool to fit the thumb nail preview to the preview area.
Press the option key while double clicking to fit the full size preview to the window.
Double click the "Glass" tool to zoom in the thumb nail preview to 1:1 ratio.
Press the option key while double clicking to zoom in the full size preview.
The double clicks do not resize the window .
(Note: The thumb nail preview is "buffered" for quick refresh.
Any zooming or scrolling may take some time to re-buffer the data from Photoshop, if the image is large.)
§ 6. Misc. Notes
The following are special cases.
6.1 Swapping the Red and Green Channels
Rotate +90° about the blue axis and invert the red channel.
6.2 Swapping the Green and Blue Channels
Rotate +90° about the red axis and invert the green channel.
6.3 Swapping the Blue and Green Channels
This is your home work :-).
§ 7. How to Reach the Author
Please send comments, bug reports, etc. to <kawahara@leland.stanford.edu>.
Visit <http://www.stanford.edu/~kawahara> for updates.
§ 8. Acknowledgment
This software was developed using
Metrowerks CodeWarrior Academic 7 and
Adobe Photoshop 3.0.4 SDK.
Adobe Photoshop is a trademark of Adobe Systems, Inc..
Macintosh is a trademark of Apple Computer, Inc..
Metrowerks CodeWarrior is a trademark of Metrowerks, Inc..
