1. Vectors and Paths, also File Export
CSC020, Computer Graphics,
Vectors and Paths, also File Export 1

2. Photoshop Paths Vector outlines are Paths.
Like Type, they are vector shapes.
Create them using the Pen and Shape tools.
You can create, save and reuse Shapes (Paths).
Vector Masks are the vector graphical counterparts to Layer Masks.
Vector Masks are sharp, precise, and consume less storage space than layer masks. 2

3. Converting a Selection to a Path
Open SymmetryLace.jpg in Folder type.
Crop to the lace projection on the screen.
Rectangular select, then Image->crop
Select lace with Magic Wand in New & Add modes.
Display Windows -> Paths (new tab next to layers).
Make Work Path from paths palette menu or Work path from Selection icon at bottom.
High tolerance gives smoother, more usable shape. 3

4. First Use of a Path
Make an empty layer (in layers tab) and select it for editing.
Go back to Path palette and Control- Click Fill Path after choosing a foreground color.
Hide the underlying image layer.
Create a middle layer of black foreground
Be sure to de-select the work path first!
Try shutting off visibility of all layers. 4

5. Manipulating a Path Highlight the path on the Paths palette.
Select Path Selection Tool (arrow) on Tools palette.
Click small, “island” path on the image.
You can copy and move a path “island.”
Use Direct Selection tool (open arrow) to select anchor points, Shift-click or drag a marquee to select more, Shift-click to remove. 5

6. Practice Manipulating Paths
Open RuoriTrapezoid.jpg, duplicate layer.
Use Polygonal Lasso to select the trapezoid.
Convert it to a Path on the Path palette.
Hide image layers.
Use Path Selection (solid arrow) and Direct Selection (open arrow) tools to select, deselect, and manipulate anchor points.
Select and move a single anchor, or a line segment by selecting 2 anchors, or a direction line. 6

7. Filling a Path Get a fresh path that matches the trapezoid.
Drag its anchors to create a rectangle.
Double click the Work Path, rename it.
Control-click the Path, Fill path to fill it.
Will appear on active layer
make sure there is an active layer first! 7

8. Setting a Path’s stroke
Stroke Path to select a stroke
right click to get menu
or … select icon
Note: Go into that stroke-specific tool first to set the stroking tool configuration parameters!

9. Pen Tool Add a new, empty Path. Select pen tool. Alt-drag
Single click to add vertices of a polygon.
Click and drag to create curved segments.
Click start point to close a polygon.
Alt-drag
create non-smooth points
Drags on one side
Enter or Escape to terminate current polygon.
Delete/Backspace deletes latest vertex.
Pen options to add or delete anchor points.
Freeform Pen! 9

10. Freeform Pen Magnetic and non-magnetic options.
Magnetic follows edges in an image layer.
Switch between Path and Shape to make either
Use shape tool to draw shapes
If path is selected, it will appear in Paths layers (under Paths tab) 10

11. Shape tool
Rectangle and ellipse use Shift-drag for symmetry (square and circle0.
Polygon shape has number-of-sides parameter.
Custom shape has library of shapes. 11

12. Path to Selection Control-click a Path, Make Selection.
New / Add / Subtract / Intersect the selection.
Load path as Selection selects just one path. 12

13. Vector Masks Shape-defined masks similar to layer-masks.
Layer -> Vector Mask -> Reveal All (white mask)
Layer -> Vector Mask -> Hide All (black mask)
Draw path shapes on mask to reveal image area.
Alt-click to edit (draw on) vector mask
Make appropriate fore/background color selection
Command-click the mask to make a selection.
You can also create a vector mask from a Path via Layer -> Vector mask -> Current Path.
Rasterizing converts Vector to Layer Mask. 13

14. PDF
PDF is useful for exporting to word processing tools that cannot read Photoshop files.
Download export.zip, Open Concert1.psd.
Note smart object with Smart Sharpen
Save as PDF without layers or Photoshop editing as nolayers.pdf
turn off Photoshop editing capabilities
Save as PDF with layers and Photoshop editing as layers.pdf
Load into PowerPoint or Word (Insert -> Picture) and compare quality.
Reopen in Photoshop – are there layers?

15. Output for Web
GIF is an 8-bit format, good for up to 256 colors, retains transparency.
JPEG uses 24-bit format with adjustable quality / file size trade-off, no transparency.
Use JPEG for continuous-tone images.
Limit image size to 800 x 600 pixels at 72 ppi for compatibility with browser screen area and resolution.
Smaller file sizes load into browsers faster. 15

16. File -> Export -> Export As
Allows selection of PNG, GIF, JPEG and SVG options.
Option to select 8 bit color
Allows selection of both image and canvas size independently
Can make tradeoffs between format, size, and file size 16

17. JPEG Quality parameters trade file size versus image fidelity.
Increasing Blur can reduce noisy artifacts caused by JPEG compression.
Matte substitutes for transparent areas.
Use of either GIF and JPEG usually requires viewing in the context of a browser.
Create / use thumbnails where possible to leave original image at higher resolution. 17

18. Inserting images into web pages.
SeaMonkey is a free, open-source browser with HTML editing ability. It comes with an editor.
Adobe editor is Dreamweaver.
Putting up a simple page to preview is straightforward. Embed an image with some text. 18