Digital Imaging 1

Fall 2014CCBC

ARTD 116 CN1, Digital Imaging 1CRN 94731

What does digital imaging? How do we use digital imaging?

Three creditsTwo lecture hours and two lab hours per week, plus .5 online work.

What to expect in the class:

Pushing your creativity with your own imagery. Try and try again when developing your Technical skills.

Come on time and prepare.

Must be an active participate in Class. What does this mean?Be part of a discussion, Ask questions,Use your neighbor for help, andadvice.Check the website and Blackboard often.

How is digital imaging used in our contemporary world (life)?

Digital Imaging I teaches the skills required for creating, manipulating, and publishing digital images for both print and interactive media; includes extensive exposure to bitmap editing software, as well as use of vector/draw programs to develop technical and creative processes.

Explain how these images are or are not an example of Digital Imaging.

Alberto SevesoDavid Hockney

Photoshop Software

Rasterized, file formats, and printing choices

Photoshop is a raster programWhat is raster program like Photoshop? Programs that use pixel colors to create a graphic.

• A raster graphic is an image made of hundreds (or thousands or millions) of tiny squares of color information, referred to as either pixels or dots. (Technically pixels refer to color blocks viewed on an electronic monitor where as dots refer to the ink dots on a printed piece. But even professional designers, myself induced, often use these two terms interchangeably.)

• The most common type of raster graphic? A photograph. The designer’s preferred program for creating and editing raster files? You guessed it: Adobe Photoshop.

• Popular raster file format extensions include: jpg/jpeg, psd, png, tiff, bmp and gif.

What is a pixel?

A pixel is a small dot of color either RBG (primary colors of light). All lighted display devices are made of pixels.

Digital Cameras have a sensor that collects color data and make an image file that contains a variety of color pixel data.

http://www.youtube.com/watch?v=uRzPBELMemM

PPI or DPI/resolution

PPI stands for Pixel per inch.DPI stands for Dots per inch.

Image is measured in the amount of pixels in a square inch.

The smaller the ppi the lower the image quality, 72 ppi is average web image size.

The high ppi like 300, offers better image quality and more options for printing.

• Pros of Raster Images

• Rich Detail: Ever wondered what the term “dpi” stands for? It means “dots per inch,” a measurement of how much detailed color information a raster image contains. Say you’ve got a 1” x 1” square image at 300 dpi—that’s 300 individual squares of color that provide precise shading and detail in your photograph. The more dpi your image contains, the more subtle details will be noticeable.

• Precise Editing: All of those individual pixels of color information can also be modified, one by one. So if you’re a true perfectionist, the level of editing and customization available in a raster image is almost limitless.

• Cons of Raster Images

• Blurry When Enlarged: The biggest downfall to raster images is that they become pixelated (aka grainy) when enlarged. Why is this? Well, there are a finite number of pixels in all raster images; when you enlarge a photo, the computer takes its best guess as to what specific colors should fill in the gaps. This interpolation of data causes the image to appear blurry since the computer has no way of knowing the exact shade of colors that should be inserted.

• Large File Size: Remember how a 1” x 1” square at 300 dpi will have 300 individual points of color information for the computer to remember? Well let’s say you have an 18” x 24” photo— that’s 129,600 bits o’ info for a computer to process which can quickly slow down even the faster machine.

Digital Measurements1 byte = 8 bit1 KiB = 1,024 bytes1 MiB = 1,048,576 bytes[1]1 GiB = 1,073,741,824 bytes[2]1 TiB = 1,099,511,627,776 bytes[3]

Referenced from Wikipedia

File Formats

RAW, TIFF, JPEG, PNG, PDF, GIF…

Why so many file formats? When to use them?

JPEG- (Joint Photographic Experts Group) Jpeg format is used for color photographs, or any pictures with many blends or gradients. It is not good with sharp edges and tends to blur them a bit. This format became popular with the invention of the digital camera.

TIFF-( Tagged Image File Format) This file format has not been updated since 1992. It can store an image and data (tag) in the one file. TIFF also stores files with virtually no compression and therefore is good for storing images that need to be edited and re-saved without suffering a compression loss.

RAW is the output from each of the original red, green and blue sensitive pixels of the image sensor, after being read out of the array by the array electronics and passing through an analog to digital converter.

PDF-Portable Document Format was developed in the early 1990s as a way to share documents, including text formatting and inline images, among computer users of disparate platforms who may not have access to mutually-compatible application software. The format is a like a screen shot but with the ability to have clickable links and buttons, form fields, video, and audio.

PNG -Portable Networks Graphic) Apparently this is one of the best image formats, however it was not always compatible with all web browsers or image software.

GIF-(Graphics Interchange Format) Gif format is best used for text, line drawings, screen shots, cartoons, and animations. It is commonly used for fast loading web pages.