Raster/Pixel/Bitmap:

Raster graphic images are a data structure representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium.

A pixel is one picture element. (like putting picture and element together).

A bitmap is the grid that contains all the pixel information (it is inherently rectangular).

Raster images are great for photos or anything with detail. They tend to be larger files so often a codec is used to lower the file size.

DPI:

Dots per inch.

Used for print.

PPI:

Pixels per inch.

Used for screens.

The greater number of dots/pixels, the higher the resolution the image but the larger the file size.

300 dpi is the excepted standard for printed content. 72 ppi is the standard for screens (tv, monitor, etc.) any less and things get pixelated.

Common Raster formats:

JPEG (Joint Photographic Experts Group, they developed it):

lossy, but are small and compatible with most computers.

Best for images with smooth transitions (paintings, photographs, not line art).

Very common on the internet.

GIF (graphics interchange format):

Very small lossy format, also supports simple animations (like those smiley face animations).

PNG (portable network graphics):

Made to replace GIF, very small, good for transferring images over the internet.

TIFF (Tagged Image File):

Not lossy and can contain an alpha channel.

Adobe owns the rights and is often used for publishing and page layouts.

PSD (Photoshop document)

Adobe Photoshop’s native format. This can only be opened with Photoshop so it is not ubiquitous. It does however, store all of things you have done in the program. This should be your default format you save to.

Camera Raw (CR2, NEF, SRF, and many more)

When you take photos with a professional camera it is possible to save them to the camera’s native format. These are very large and difficult to work with but are high fidelity. It is generally not suggested to use this format for this course initially.

Destructive Editing:

Broadly speaking image production workflows can be organized into two camps, destructive & non-destructive.

In a destructive workflow the edits you make to an image are permanently changing the pixels. The only way to change a previous edit is to undo all the way back to it, losing anything you may have done after.

Non-destructive workflows allow you to make change anything you have done whenever you want without losing any work. Obviously non-destructive is prefered but is not always possible with all tasks

Common Destructive Tools:

Adjustments

When you select Image>Adjustments these tools adjust the image or marquee selection as a whole. These adjustments include things like hue, saturation, contrast, balance, etc.

Filters

The functions in the Filters menu affect whole image areas and are also destructive, permanently affecting the pixels. Filters include things like blur, sharpen, warp, etc.

Tools

Most of the tools in the toolbox are considered destructive.

Common Commands:

cmd/ctrl + z:

Undo/Redo

cmd/ctrl + alt + z:

Step backwards (undo)

cmd/ctrl + shift + z:

Step forwards (redo)

cmd/ctrl + c:

Copy

cmd/ctrl + v:

Paste

cmd/ctrl + t:

Free transform (move, rotate, scale)

cmd/ctrl + j:

Duplicate layer

cmd/ctrl + d:

Clear selection

cmd/ctrl + +:

Zoom in

cmd/ctrl + -:

Zoom out

cmd/ctrl + s:

Save

Tools:

v:

Selection tool

m:

Marquee select tool

l:

Lasso select tool

w:

Magic wand/smart select tool

c:

crop

i:

Eyedropper tool

j:

Healing brush tool

b:

Brush tool

s:

Clone stamp tool

y:

History brush tool

e:

Eraser tool

g:

Fill tool

o:

dodge/burn/sponge tool

p:

Pen tool

t:

Text tool

a:

Direct selection tool

u:

Rectangle tool

spacebar:

Hand tool (panning)

z:

Zoom tool

q:

Quick mask mode

Did you remember to?

• Read through this webpage
• Submit Week 02 Image Restoration Assignment on Blackboard
  
  • original image, repaired image, and project cover sheet