Transcript Introduction to Photoshop Christy Avery Peer-led workshop December 2, 2009 Why might you want to use Photoshop? • Change color mode, size etc.

Introduction to Photoshop
Christy Avery
Peer-led workshop
December 2, 2009
Why might you want to use
Photoshop?
• Change color mode, size etc. (i.e.
formatting graphs for journals)
• Adding in text not easily incorporated in
graphing package
• Sprucing up graphs, moving around
results, etc.
Title bar
Photoshop Desktop
Ruler
Toolbox
Palettes
Toolbox
Tool
Name
Purpose / how to use
Marquee
Click and drag to select part of the image
Move
Click and drag to move a selected area or an
entire layer.
Type
Click the image with the type tool where you
want to add type. Then start typing.
Zoom
Click or drag to zoom in (to zoom out, press the
Alt key)
Hand
Drag with the hand tool to move around an
image
Getting an image into Photoshop
• When you first launch Photoshop, the Photoshop
desktop appears.
• There are three main ways you can bring an image into
Photoshop:
– You can open an existing image file by choosing File > Open or
File>Browse. Photoshop can open most image file types.
– If connected to a scanner with a Photoshop plug-in that has
been properly installed, you can scan an image into Photoshop
by Choosing File > Import.
– Create a new Photoshop
file from scratch: choose
File > New. Give your
file a name, and then
choose a preset from the
Preset dropdown menu,
or enter information for
width, height, resolution,
and color mode (usually
RGB).
Color Modes
• Whenever you are working in Photoshop, you
are working in a color mode.
• To change color modes, choose Image > Mode.
• The default mode is RGB mode: three channels
(Red-Green-Blue)
– Default mode for the web.
• CMYK mode: four channels (Cyan, Magenta,
Yellow, Black)
– used by professional printing houses. If you are
producing a images for a publication or poster, you
may need to save it in CMYK mode.
Image Size, Resolution,
and Print Size
• One way to learn about
concepts related to image
size, resolution, and print
size is to experiment with
an image using the Image
Size dialog box.
– Open an image in Photoshop, choose Image > Image Size, and the Image Size
dialog box appears.
– Under Pixel Dimensions, Width and Height refer to the number of pixels in an
image, which has to do with the size of display on screen. Under Document
Size, Width and Height refer to the size of the image when printed.
– Sampling up (increasing the number of pixels) makes images larger on a
display screen.
– Under Document Size, there is a tradeoff between Width and Height and
Resolution. If you increase the width and height, resolution decreases. If you
increase the resolution, width and height decrease.
Working with Layers
• Images in Adobe Photoshop are made up of
layers. Initially, each image has only one layer
(called the background layer), but you can add
more layers to the image.
• Layers are very useful for editing and adding
images (also special effects). For example, you
could make a copy of a layer and make some
changes to it. If you don't like the results, you
can delete the layer and still have
your original layer as a backup.
• To work with layers, display the
Layers palette by choosing Layers
from the Window menu.
Working with Layers
• The first column of the layers palette shows which layers
are currently visible, indicate by the eye icon ( ).
• To make a layer the current layer, click on the layer in
the Layers palette.
• To change the name of the layer, double-click on the
layer's name, then type in a new name.
• To create a new layer, click the new layer icon at the
bottom of the Layers palette, or duplicate a layer by
dragging the layer to the new layer icon.
• To delete a layer, click the trash icon, or drag the layer
to the trash icon (next to the new layer icon).
• To lock (prevent changes to) a layer, click one of the
Lock: boxes near the top of the layers palette. From
Working with Layers
• One advantage of layers is that they can
be used to combine images. You can
combine images by opening two images in
Photoshop, and then copy and pasting a
selection from one image to another,
which also creates a new layer
• Flattening layers (LayerFlatten image)
compresses all layers into one. This is
necessary once your are done editing and
helpful if you need to move part in the full
picture (see examples).
Adding Type to Images
• To add type to images use the Type tool ("T" in the
Toolbox).
• To enter a single line of text, click on the image with
the type tool and type. A type layer is automatically
created.
• To reposition the text while you are using the Type tool,
press the Ctrl key. The Type will change into the move
tool (
) so you can move the text box.
• To adjust the color and format of your type, double
click the layer, highlight the type and then change the
settings using the options that appears in the Options
bar whenever the Type tool is selected).
• When you use the Type tool, a type layer is automatically
created. As long as your type is on a Type layer it is
editable until you flatten it.
Painting Techniques
• To isolate an area you want to paint, make a selection.
This protects the non-selected (masked) area of the
image from painting. If you want to paint on the entire
image, make sure nothing is selected.
• The paint brushes paint with the current
foreground color, which is shown in the
toolbox. The default foreground color is
black and the default background color is
white.
• To swap the foreground and background colors, click on
the double-sided arrow
• To choose a new color, click on the foreground color in
the toolbox, and the color picker will appear.
• Or, use the eyedropper tool ( ) to click on a color in
your image you wish to use.
Painting Techniques
• Using the Paint Bucket (K)
• The Paint Bucket fills areas in the current
foreground color.
• 1) Use the marquee ( ) tool to select the area
you want to change.
• Choose the Paint Bucket tool.
• Click inside the area selected by the marquee
tool with the paint bucket.
• Note: sometimes it is helpful to first flatten all
images (i.e. do this towards the last stages of
image manipulation).
Final Steps in Preparing Images
• When saving or exporting files, you need
to save images as TIF, GIF or JPEG.
(Native Photoshop format (.psd) is not
word or otherwise compatible.) To do this
you can use File > Save As.
• Photoshop's native format allows layers,
but other file formats do not. When you
save a file as anything other than a .psd,
any multiple-layer file will be flattened.
Photoshop Before and After
Here, I used Photoshop to align the four graphs, remove the blue background
and legends from each graph, and remove the y-axis for the right two graphs.
I also added new text (as the stata-generated titles were blue). (I found I needed
to use the “overlay” paint bucket option to replace some of the blue, fyi.)