Picture Lab

Manipulating Pictures

• Discussion and activities with java.awt.Color introduce students to megapixels, pixels, the RGB color model, binary numbers, bit, and byte.

• Processing individual pixels involves 2D array concepts: row-major order, column-major order, array of arrays, and nested loops.

• And more…

Intro to digital pictures and color

• 20 minutes – 1 hour

Picking a color

• Students practice making different colors using combinations of red, green, and blue light using a JColorChooser.

• 20 minutes – 1 hour

Exploring a picture

• PictureExplorer tool • Pixelation• 20 minutes

– 1 hour

Two-dimensional arrays in Java (Optional activity)

• Students write methods for 2D array of integers. – Declare 2D array– Create 2D array– Get or set elements– Get number of rows/columns

0 1 2 0 1 2 3

1 4 5 6

– Traverse in row-major and column-major order• 30 minutes – 1 hour

Modifying a picture • OOP Concepts • 1 – 2 hours

Mirroring

• Loop through a range of rows and columns. • 1 – 2 hours

0 1 2 3 4

0

1

2

Mirroring part of a picture

• Loop through a range of rows and columns. • 1 hour

Creating a collage

• Overload copy method • Modifying • Mirror the resulting collage. • 1 – 3 hours

Collage with vertical mirror

Simple edge detection

• Calculate color difference with distance formula

• 1 – 3 hours

Extensions – in Teacher Guide

• Steganography

• Chroma key