Lab 5: Image Manipulation
Introduction
In this lab we will use Photoshop to alter an image and make the alteration appear as
authentic as possible. Photoshop and similar programs have made it possible to
alter images in a wide variety of ways, while still appearing realistic. Photoshop has a
great deal of functionality in the area of graphics and image creation
and manipulation. Today's lab will focus on using certain tools to alter an image.
If you wish to use other functions of Photoshop as part of your
project, feel free to explore them on your own. There's lots to learn,
so blaze away!
Objectives
- To use Adobe Photoshop to select and manipulate areas of an image.
- Remove and add selections to an image.
- Through the manipulation of photos, create an awareness about issues of authenticity
and misinformation in photographic displays.
To Do
Get to know the Photoshop Application Environment
Open the program Adobe Photoshop from the Start Menu. When the program loads, you should see a screen similar to this one. The Tool Box (shown here on the left) contains a number of tools that can be used to work with images.
- Marquee Tools: The marquee tools let you select rectangular or elliptical
areas in an image.
- Crop Tool: This tool allows you to select an area of an image and crop it.
- Lasso Tools: The lasso and polygon lasso tools let you draw both straight-edged
and freehand segments of a selection border.
- Magic Wand Tool: The magic wand tool lets you select a consistently colored area
(for example, green grass) without having to trace its outline.
- Clone Stamp Tool: Takes a sample of the image, which you can then apply over another
image or part of the same image. Each stroke of the tool pains on more of the sampled
image. This tool is also called the Rubber stamp Tool.
- Eyedropper Tool: Sample color from an image to indicate a new foreground or
background color.
- Paint Bucket Tool: Fills adjacent pixels that are similar in color value to the
pixels that you click.
- Horizontal Type Tool: Allows you to add layers of text to your photo using different
fonts, sizes, and colors.
2. Make Copies of Images For the Lab
The first thing to do is get a copy of the images we'll work with and save them to a disk
or a local drive. Here are the images again: goose and
fence. Right click on each of the links and choose
Save Image As... Be sure to put the pictures on your desktop or some other
obvious location.
- Open the images in Photoshop using File > Open... They should be in the "obvious"
location you just saved them in.
- Since an unaltered copy will come in handy if you mess up or want to use these images
again for something else, create a copy of each one: File > Save As... and give them
the names goose_copy.jpg and fence_copy.jpg, respectively. Now you will be working on the copies while still keeping the originals.
3. Adjust Image Color
NOTE: Whenever you want to indicate that you are dealing with one image
versus another, make sure that the image is "selected." That is, click somewhere on the
image you want to work with to select it.
- To lighten or darken one of the images, adjust the RGB color levels
Image > Adjustments > Level... Using the slide bar on the right and left sides of the
Input Levels, decrease the amount of darkness in the image, without making it too bright.
When you are satisfied, click OK and go back to your image.
- Make sure to save your changes using File > Save
4. Crop an Image
Select the goose image. You're now going to use the crop tool to remove information around the edge of the image.
- Select the Crop Tool
- Starting with the top right corner, click and drag a box around the goose. Try and
fit it so the goose is in the center of the image.
- Right click on the area you have cropped and click on Crop to finish the action or hit Enter.
- Save your work!
5. Remove Objects from an Image
Now you'll remove a leaf from the goose image.
We'll do this by "painting over" the leaf using the color and texture of the nearby grass.
- Select the Clone Stamp Tool (also called the Rubber Stamping Tool). While
holding down the ALT key, use the mouse to click on an area of grass near the leaf to the
right of the goose. This is your "sample" location. It is important that you click near the leaf you
are removing so that you get the color grass that is closest to the color under the leaf.
- Look at the size of the leaf. Select the proper brush size to paint over the leaf. If the
Options box is not showing for Brushes, go to the menu bar and select Window > Brushes.
Select a brush that will cover the area. You will decide whether to use soft or hard edges.
- Move your mouse over the leaf while holding down the left mouse button. The area is replaced
with color/texture from the sample area!
NOTE:Any time a move or action is taken that you don't want to keep, use the
Edit > Undo button to remove the last step taken or use Ctrl+Z to undo only the last step.
6. Select an area of an Image by Color
Using the Magic Wand Tool, you can select whole areas by their similarity in color.
- Make sure that you are in the fence image. Go to the layers window and double click the
only layer there - Background. You will see the following:
- Click OK. This will be important later.
- Now select the Magic Wand and click on a gray area on the fence image. It will be outlined.
- To add to the area, hold down the Shift key as you click on other gray areas. The areas you click will become part of your selection
(To subtract selected areas one at a time, use the Alt key).
- Continue adding all of the gray areas, the "holes" in the fence until you have selected
them all (but don't worry too much about the very small ones).
- Don't deselect them just yet, will use this in the next step.
7. Remove a Color in an Image
In a few moments you are going to put the image of the goose into the image of the fence so it appears
that the goose is standing behind the fence. To that end we will create "empty" spaces in our
image where the fence holes are. When there is no color value for a given pixel we say that
it is transparent, beware that the color white is NOT transparent.
- Hit Delete. The checkerboard pattern means that those spaces are empty, e.g. there is no image data there.
8. Insert one Image into another using Layers
- In the fence image, go to the Layers window and right click on Layer 0.
- From the drop down menu choose Duplicate Layer...
- Choose to Save As: Layer 1 and in the box Destination for Document use the drop down menu to
choose goose.jpg. Click OK. Now you have a new layer in goose.jpg with all the information
form the fence layer.
- Go to the goose image. With the new layer selected, use the Move Tool and adjust the
fence so the goose "looks" through one of the holes. :)
9. Add Text to the Image
Use the Horizontal Type Tool (i.e. the Text Tool) to add a layer of text into you image.
- You can give a title and date to the fake image - Goose in Captivity, January 2006 -
or simply practice with different fonts.
- Use the menus at the top of Photoshop page to adjust font size and color for the layer of
text.
- When you have finished typing your text, use the move tool on that layer to place the text
in the best location on the image.
- Experiment with layer options: choose the text layer, then go to the menus
Layer>Layer Style>Drop Shadow, then choose ok and now your text layer has a shadow.
Flatten the Image
In order to save our new image as a .jpg or a .gif, we need to flatten the image. To do this
you will combine the multiple layers that currently make up the image into one. This reduces
the size of the file. Once an image is flattened, the layers can no longer be modified independently.
- Select the Layer > Flatten Image on the menu bar across the top. The image is now
a single layer, instead of three different layers.
- Save your image.
When you are done, create a lab5 folder under your fit100 folder on your Dante account, and save your finished product, goose_copy.jpg into the lab5 folder.
A Note on Copyright
One of the major issues associated with images (and music and movies) is the issue of
ownership. We need to be extremely careful in respecting the copyright
associated with the image, while at the same time recognizing that there are personal
use rights allowed under copyright law (although this is under significant pressure).
In this lab, we have provided you with two images taken by the staff of the class that you
have explicit permission to use. These images are goose and fence. For Project 1, you will need to produce your own set of images.
When you create images for the project, be sure to verify that you have permission to use any images that you choose.
Most US government agencies provide their images copyright free (because the
taxpayers have already paid for them). Many web sites and photo collections are being
provided using Creative Commons licenses (http://creativecommons.org/image/) that allow you to use the images as long as you
credit the original photographer and use a similar license on your resulting image.
Learning More
This lab is focused on the use of Adobe Photoshop for photo manipulation.
There is a great deal of functionality to the software that we didn't cover. Find out for
yourself different ways to use the tools in Photoshop. You could even try to do many of the
same things done in this lab with another image manipulation program, like MS Paint.
Adobe Photoshop Tutorials:
http://www.adobe.com/products/tips/photoshop.html
Online Course for Adobe Photoshop Basics:
http://graphicssoft.about.com/library/course/bllps5out.htm
