Held: Friday, 19 February 2016

Back to Outline 15 - Homogeneous Lists: Making and Manipulating Groups of Drawings . On to Outline 17 - Boolean Values and Predicate Procedures.

Summary

We continue our synthesis of algorithms and image making as we explore techniques for programming with the basic GIMP tools.

Related Pages

• Reading: The GNU Image Manipulation Program
• Reading: Programming the GIMP Tools
• Lab: Scripting the GIMP Tools
• EBoard 16 (Source 16)

Overview

• A new model of images making.
• Coding algorithms for drawing.
• Other useful techniques.

Administrivia

• Continue partners!

Reminders

• Office hours: MTWF 10-11, Tu 1-2.
  • Sign up at http://rebelsky.youcanbook.me.
  • Also feel free to stop by when my door is open.
  • Or to email me for an appointment.
  • Probably no office hours on Friday b/c of swim meet.
• Tutor hours
  • Sunday, 3-5 p.m.
  • Sunday-Thursday, 7-10 p.m.
• Weekly review sessions:
  • Wednesday at 8pm in the CS Commons with
  • Thursday at 10am in this room with
  • Thursday at 8pm in the CS Commons with

Upcoming Work:

• Reading for Monday:
  • Boolean Values and Predicate Procedures
• Assignment 4 due next Tuesday at 10:30 p.m.
• Lab Writeup: Exercise _
  • Send email titled CSC 151 Lab Writeup 15 (Your Names)
  • Do not include the underscores.
  • Send to CSC151-02-grader@grinnell.edu
  • Due before class on Tuesday.

Extra Credit

• Send your reports to rebelsky@grinnell.edu with subject "CSC 151 Extra Credit".
• Send opportunities to me before class with subject "CSC 151 EXTRA CREDIT OPPORTUNITY!"

Academic

• Monday's Data on Students Presentation, noon, JRC 101, with lunch

Peer

• Swim Meet, Friday, Saturday, and Sunday, Osgood Pool. (30 min.)
  • "Daniel is really awesome." (1pm Sat for prelims; ? for finals)
• Lunar New Year Festival, Saturday 5:40 pm until 7:30 pm in Harris.
• Pun Club Tournament Friday the 26th in the evening.
• Contra Dance Friday the 26th in the evening.
• Improv Show the 27th in the evening in Loose Lounge.

Regular Peer

• Social Dance Workshop Tuesdays 7:00-8:00 in Bucksbaum Dance Studio
• Pun club Saturdays at 4pm in Younker (max 2)
• Electronic Potpourri on KDIC Fridays at Five (TONIGHT)
• Space Odyssey KDIC Fridays at Six

No Extra Credit, But Still Good

Models of Images

• As we've seen in our early discussions, there are many ways to think about an image.
• In our first explorations with the GIMP, we looked at an imperative, tool-based model of drawing.
  • The model is imperative in that it consists of a sequence of commands (do this, then this, then this).
  • The model is tool-based in that almost all operations involve selecting a tool and then applying that tool.
• Over the next few weeks, we'll see a variety of other models.

Encoding Drawing Cmmands

• Because there are only a limited number of basic actions one can perform in GIMP, it is possible to represent each of these actions as a procedure.
• These procedures are parameterized in that you can modify how they work by providing different input values.
• Many of these procedures change the state of the system. When procedures change things (as opposed to computing new values), we tend to suffix their name with an exclamation point.
• For clarity, we tend to prefix the name of a procedure with the kind of value it works on. For example,
  • procedures that modify and create images begin with image-,
  • procedures that modify the global context begin with context-,
  • procedures that modify and create colors begin with color-.
• The primary model we use is to repeatedly select and then stroke or fill regions.
• We do not expect you to remember all of these procedure names.
  • One of the flaws of the current strategy for teaching 151 is that there are way too many procedures to remember.
• There is (or should be) a convenient reference menu in MediaScheme.
  • There is also a convenient reference section on the Web site.
• If there's something that you want documented, bug me.

Lab

• Work on the labthe lab.
• Be prepared to reflect on some of the questions contained therein.