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March 8, 2010

Graphics.drawPath()

Filed under: Flash — ctyeung @ 9:21 pm

I came across a really good article by Trevor McCauley on a number of new Graphics methods for Flash 10.

Thought I tried 2 of his examples here, drawPath & winding.  Pretty impressive for finding overlapped area.

March 6, 2010

Dashline with pixelbender

Filed under: Flash — ctyeung @ 5:56 pm

There are already many dashline classes written in actionscript.  But thought it will be fun to try it with pixelbender.  I must admit that the product is not so-so.  But here is it, PBDashline.

February 16, 2010

Convolution filters for interpolation

Filed under: Flash — ctyeung @ 10:02 pm

By default, Flash and Flex offers bilinear interpolation.  A number of articles offer cubic spline interpolation to achieve better result for enlargement.  The major draw back is performance.  Here I am “experimenting” with cubic spline, pyramid and rect filters for 2X enlargement.  The implementation is done in pixelbender for speed and simplicity.  However, I sacrifice the flexibility of arbitrary enlargement size.

Consider my demo and source.

Reference: Digital Image Processing (second edition) by William K. Pratt pages 441 – 445.

January 16, 2010

AIR 2.0 feature – launch default application

Filed under: Flash — ctyeung @ 9:31 pm

Wow, awesome feature.  Lesson, thanks to MNSWF and our very own Dustin of Easel Training.  Example here will detect a USB jump drive plugging in and launch the default application when you click on the file.

source-code, installer

December 4, 2009

Boolean image operators

Filed under: Flash — ctyeung @ 11:29 pm

I really appreciate Flex BlendMode features.  To complement, here are some primitive boolean operators in pixel bender for 2 images.

Gates: AND, OR, NAND, NOR, XOR.

For demo and source code, try this Flash builder demo.

November 29, 2009

Adjust HSV

Filed under: Color, Flash — ctyeung @ 2:06 pm

Thought I would try applying HSV in pixelbender as well.  The  algorithm I am using maybe referenced from University of Haifa, Israel.  Please consider my Flex app. demo and pixelbender source (pbk).

November 27, 2009

Adjust CIE L*a*b*

Filed under: Color, Flash — ctyeung @ 11:41 pm

Thought I exercise on a pixelbender filter for adjusting brightness (L*), red<->green(a*), and yellow<->blue(b*) in CIE L*a*b* color space.  I am generalizing the sRGB to Tristimulus (XYZ) formulation and assuming D50 light source.

PixelBender source (pbk)Flex App. demo

Reference(s):

1) Principles of Color Technology, 2nd edition by Billmeyer & Saltzman.

2) http://en.wikipedia.org/wiki/SRGB

November 16, 2009

3×3 Matrix transform

Filed under: Color, Mathematica — ctyeung @ 7:58 pm

A few months ago a friend from FlashMN asked about finding a coordinate transform from one volume (3D space) to another.  Well, here is one of the simplest method, solving for a 3×3 matrix (assuming linear, non-distorted transform on a plane).  This is written in Mathematica 7 notebook.  Reference: Measuring Color 2nd Edition by R. W. Hunt, pg. 204-5.

October 21, 2009

BobbleHead

Filed under: Flash — ctyeung @ 10:45 pm

Happy Halloween!  Topic for FlashMN this month was BobbleHead.  Here is the result with a few refinement after the meeting.  Mouse out, click or drag to repeat the bobble.

Bang Bang!

October 11, 2009

VolumeHistogram

Filed under: Flash — ctyeung @ 10:21 pm

Color pixel coordinates are three dimensional and therefore best visualized and manipulated in a volume.  The first time I experienced this was through a statistic analysis tool, JMP (SAS software) in my color theory class at Rochester Institute of Technology (RIT).  Later, I have used similar color visualization and manipulation tools as ColorBlind and Candela by Bruce Lindbloom.

This volume histogram was first written in C# and later migrated to Flex. Added this evening was onEnterFrame() for the rotation control so as to have “spin” animation.  This tool was developed for visualization and count only.  Hope to have manipulation capability in the next version.

Download Flex and C# demo source from GoogleCode.

Learn more about the C# demo here.

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