CogSci 3 Assignment 2b
Due Saturday, October 17th (11:59pm!)
Goals
You are going to continue your work with Photoshop CS3. In this assignment you will learn how to color and transform parts of an image independently from the rest of the image.- For this Photoshop CS assignment
you will:
- learn how to make a seletion,
- apply a color gradient,
- and then work with filters.
You may print a copy
of this assignment if you wish. However, we recommend that you access the assignment online as
there may be links on this document to other related
information, and the online version is always the most recent one, in case changes need to be made.
These instructions presume that you work on
this assignment on a Windows XP computer.
Note: Photoshop CS is available on a limited number of machines on campus.
We strongly recommend that you work on the computers in class lab(s).
Log In
If you are already logged in, you can skip ahead. Otherwise, review the instructions in a previous assignment on how to log in. Then log into your class file server.
Create your homework folder
Once you are logged in:
- You should already have the hw2 folder in the "Class Resources" folder on the PC file server from the previous photoshop assignment
- And save your work to that hw2 folder.
Get your tomatoes!!
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Using the Magnetic Lasso Tool
- You can create oddly shaped selections with the Lasso toolset. There are three options: Lasso tool, Polygonal Lasso tool, and Magnetic Lasso tool. Once you make a selection, you can then move, delete, or stylize the selected area using other Photoshop tools.
- In this assignment we will use the Magnetic Lasso tool as this image has well-defined edges (the tomatoes have well defined edges!)
- To select the Magnetic Lasso, click and hold the Lasso tool and select the Magnetic Lasso
from the list that appears.
- Click the edge of the tomato that appears closest. This creates a beginning anchor point.
- Drag your cursor along the edge of the object. The Magnetic Lasso's path snaps to the edge of the element as your drag.
- To help guide the lasso, you can click to add anchor points as you go along the path.
- To erase recently drawn segments and anchor points, press the Delete key until you've erased the anchor points for the desired segment.
- Click the beginning anchor point to finish your selection.
- You will get an animated line when Photoshop recognizes you have closed the outline
Adjusting the Magnetic Lasso Tool
You can use the Options bar to adjust the Magnetic Lasso tool's precision.
- Width: The number of nearby pixels the lasso considers when creating a selection. If you magnify the edge you are slecting, you can typically decrease the width.
- Edge Contrast: How much contrast is required for the lasso to consider something an edge. You can decrease the edge contrast to select fuzzier edges.
- Frequencey:The frequency of the anchor points. You can increase the frequency for better precision when selecting poorly defined edges.
Make a new Layer
Photoshop will allow you to add splashes, streaks, or solid areas of color to your image. For this part of the assignment you will apply a color gradient to one tomato, fill another tomato with different color, and apply a filter to the third one.
A gradient is a transition from one color to another. This can give objects or area in your image a shaded or 3D look.
- Select your tomato. (It's probably still selected, if not see previous step.)
- Make a new layer. (See previous assignment for New Layer instructions.)Select that layer. It should look like you have the tomato selected, however you have the area just "above" on Layer 1.
Apply a color gradient to your selection.
- Click the Gradient tool.
- Click the gradient swatch. (The Gradient Editor will appear.)
- Select a preset gradient type from the top list box.
