==============================   EXERCISE: reduce an image

> Picture p = new Picture( "/Users/wallingf/Desktop/ew-small.jpg" );
> p.show();
> p
Picture, filename /Users/wallingf/Desktop/ew-small.jpg height 72 width 55



* how can we make an image *larger*?
  - one simple approach: repeat pixels
* write a method to do it...


> p = p.scaleUp();
> p.show();
> p.write( "/Users/wallingf/Desktop/ew-bigger.jpg" );

> p = new Picture( "/Users/wallingf/Desktop/mountain.jpg" );
> p.show();
> p = p.scaleUp();
> p.show();
> p.write( "/Users/wallingf/Desktop/mountain-bigger.jpg" );

* how can we do this better?
  - one simple approach: fill in new slots with "average" pixels
* at home: write a method to do it...


==============================   EXERCISE: what does mysteryMethod() do?


==============================   TASK: change color of my shirt

> p = new Picture( "/Users/wallingf/Desktop/wallingf-250x328.jpg" );
> p.explore();

* try (79,246) - 175/138/156
* I'd like a Kelly green:

> ColorChooser.pickAColor();
* 0/102/0
* try to bring color close to this

> Picture p = new Picture( "/Users/wallingf/Desktop/wallingf-250x328.jpg" );
> p.explore();
> p.mysteryMethod();
> p.show();


* this makes the image greener
  - but I want to change only the shirt's color!
  - what is the color?

* use explorer to find ( 163, 124, 143 )
* try to change any pixel with this color
> p.explore()
  - actually, *close* to this color
  - aPixel.colorDistance()


==============================   SLIDES: Guarded Action


==============================   TASK: remove camera glare from glasses

> p = new Picture( "/Users/wallingf/Desktop/wallingf-250x328.jpg" );
> p.explore();

* (200,179,158) @ ( 97,92)   --   glare
* (182,122, 70) @ (142,93)   --   flesh

- look in small region (92,87)-(103,96) and replace glare...
* see code

> Picture p = new Picture( "/Users/wallingf/Desktop/wallingf-250x328.jpg" );
> p.show();
> p.eliminateGlareInGlasses();
> p.repaint();

* problem: one pixel was so white, it failed the test!
* try a large epsilon... 75, 100?
* working with media requires experimentation


==============================   TASK: remove red eye

* the text's removeRedEye method does just this
  - but takes as arguments the range and the color
  - still hardcodes color to replace (red) and distance (167)

> Picture p = new Picture( "/Users/wallingf/Desktop/sarah-headshot.jpg" );
> p.show();
> p.explore();


* on Sarah: find range (110,247)->(120,260) and use black

> import java.awt.Color;
> p.removeRedeye( 110, 247, 120, 260, Color.black );
> p.repaint();

* problem?   "pink eye"
* solution?  make the distance a parameter, too

> p.removeRedeye( 110, 247, 120, 260, 200, Color.black );
> p.repaint();


==============================   EXERCISE: how to remove only red *eye*?

> p.removeRedeye( 0, 0, p.getWidth(), p.getHeight(), 200, Color.black );
> p.repaint();







==============================   TASK: edge detection

* use explorer to walk boundaries on the mountain           * aPixel.getAverage()

> p = new Picture( "/Users/wallingf/Desktop/mountain.jpg" );
> p.detectEdges( 25 );
> p.show();

> p = new Picture( "/Users/wallingf/Desktop/wallingf-250x328.jpg" );
> p.detectEdges( 25 );
> p.repaint();
> p = new Picture( "/Users/wallingf/Desktop/wallingf-250x328.jpg" );
> p.detectEdges( 15 );
> p.repaint();

> p = new Picture( "/Users/wallingf/Desktop/sarah-headshot.jpg" );
> p.detectEdges( 15 );
> p.repaint();
> p = new Picture( "/Users/wallingf/Desktop/sarah-headshot.jpg" );
> p.detectEdges( 10 );
> p.repaint();
> p = new Picture( "/Users/wallingf/Desktop/sarah-headshot.jpg" );
> p.detectEdges( 5 );
> p.repaint();


==============================   SLIDES: Alternative Action, Computer Vision