Lossless Compression - a data compression algorithm that allows the original data to be perfectly reconstructed from the compressed data.
Lossy Compression - (or irreversible compression) a data compression method that uses inexact approximations, discarding some data to represent the content. Most commonly seen in image formats like .jpg.
Lesson 04 - Encoding COLOR Images
LESSON MATERIALS (YOU CAN ACCESS ONLY VIA @BERGEN.ORG ACCOUNT)
Objectives
Students will be able to:
Use the Pixelation Tool to encode small color images with varying bits-per-pixel settings.
Explain the color encoding scheme for digital images.
Use the Pixelation Tool to encode an image of the student’s design.
Hexadecimal - A base-16 number system that uses sixteen distinct symbols 0-9 and A-F to represent numbers from 0 to 15.
Pixel - short for "picture element", the fundamental unit of a digital image, typically a tiny square or dot that contains a single point of color of a larger image.
RGB - the RGB color model uses varying intensities of (R)ed, (G)reen, and (B)lue light are added together in to reproduce a broad array of colors.
Lesson 03 - Encoding B&W Images
LESSON MATERIALS (YOU CAN ACCESS ONLY VIA @BERGEN.ORG ACCOUNT)
Objectives
Students will be able to:
Explain how images are encoded with pixel data.
Describe a pixel as an element of a digital image.
Encode a B&W image in binary representing both the pixel data (intensity) and metadata (width, height).
Create the necessary metadata to represent the width and height of a digital image, using a computational tool.
Image - A type of data used for graphics or pictures.
metadata - is data that describes other data. For example, a digital image my include metadata that describe the size of the image, number of colors, or resolution.
Pixel - short for "picture element", the fundamental unit of a digital image, typically a tiny square or dot that contains a single point of color of a larger image.
Lesson 02 - TEXT COMPRESSION
LESSON MATERIALS (YOU CAN ACCESS ONLY VIA @BERGEN.ORG ACCOUNT)
Objectives
Students will be able to:
Collaborate with a peer to find a solution to a text compression problem using the Text Compression Widget (lossless compression scheme).
Explain why the optimal amount of compression is impossible or “hard” to identify.
Develop a strategy (heuristic algorithm) for compressing text.
Describe the purpose and rationale for lossless compression.
Heuristic - a problem solving approach (algorithm) to find a satisfactory solution where finding an optimal or exact solution is impractical or impossible.
Lossless Compression - a data compression algorithm that allows the original data to be perfectly reconstructed from the compressed data.