Due: 10:00 a.m., Tuesday, 11 September 2007
Summary: In this assignment, you will use the color manipulation operations you learned in the lab on RGB colors to blend colors together.
Purposes: To get you comfortable working with the basic color operations in the GIMP. To help you think about colors.
Expected Time: About one hour.
Collaboration: I would prefer that you work in groups of size three. However, you may work alone, in a group of size two, or a group of size four. You may discuss this assignment and possible solutions with anyone you wish. If you discuss this assignment with people other than group members, make sure to include a citation (e.g.,
I consulted this person, who helped me do this).
Submitting: Email me your answer. More details below.
Warning: So that this assignment is a learning experience for everyone, I may spend class time publicly critiquing your work.
A common effect in digital graphics is a color blend, in which colors range more or less smoothly from one color to another. For example, this image shows a blend from blue to red: . Isn't it beautiful?
What tools does one need to construct blends like the above? You must
know how to manipulate the red, green, and blue components of colors used
in digital images. ANd you know that. In particular, you can extract
the red, green, and blue components of a color using rgb.red, rgb.green,
and rgb.blue, and you can construct an RGB color using rgb.new. Along
with basic mathematical operations and the
operation, this is enough to let you construct blends images.
(a) For your first blend, create definitions to assign the names
color1 to two of your favorite colors from the lab on raster graphics. Then write Scheme instructions to create an image 11 pixels wide and 1 pixel high that is a blend from
How should you blend the colors? That's up to you. As a hint, you might want the middle pixel to be the average of
You might also note that there are ten transitions we make in going from
(b) For your second blend, assign the names
color1 to one of your favorite colors and a pseudo-complement of that color. Use the Scheme instructions you wrote in (a) to generate a blend from
color1. What do you notice about the colors in the middle? Why does this happen?
Create a 5 x 5 image with a different color in each of the four corners. Then, fill in the edges with a blend of the two corner colors. Finally, fill in the middle with a blend as well. How should you blend the colors in the middle? Again, it's up to you.
I intend to evaluate your assignment on the correctness and elegance of your solution. That is, is what you've done something that could be reasonably considered a blend, and have you chosen a technique that is clear and easy to understand.
Please submit this work via email. The email should be titled CSC151.02 Assignment 04 and should contain your answers to all parts of this assignment.
Please send your work as the body of an email message. I don't like attachments, and prefer not to receive them when they can be avoided.
Thursday, 6 September 2007 [Janet Davis]
Thursday, 6 September 2007 [Samuel A. Rebelsky]
Friday, 7 September 2007 [Samuel A. Rebelsky]
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