Summary of notes and questions that are likely to be asked on exam

Pixels was first called

''Picture Element''

Unit is

''dpi''

What does ''dpi'' stand for?

''dots per inch''

What values does Black have?

(0,0,0)

What values does Red have?

(255,0,0)

What values does dark Orange have?

(255,140,0)

What values does Yellow have?

(255,255,0)

What values does White have?

(255,255,255)

What values does Grey have?

(50%) (128,128,128)

What are the extensions for a RAW Format

.CR2 for Canon .NEF for Nikon .ORF for Olympus .DNG (adobe) - digital image

Let's imagine a 24 bits image (8 per channel), each color has a range of 256 values and the range actually goes from

0 - 255

What's the table for a grayscale image?

1 bit = 2 colors 2 bits = 4 colors 3 bits = 8 colors 4 bits = 16 colors 5 bits = 32 colors 8 bits = 256 colors

Resolution is a number of pixels in a segment of

1 inch

What are the 4 important aspects of a bitmap image?

1) Definition 2) Resolution 3) Color depth 4) Format

Peripheral devices:

1) Input devices 2) Output devices

What is a part of hardware

1) Major hardware 2) Second memory 3) Pheripheral devices 4) Micellaneous parts

Output devices

1) Monitor (screen) 2) Printer 3) Projector 4) Headphones 5) Speaker

Input devices

1) Mouse 2) Keyboard 3) Graphics tablet 4) Scanner 5) Microphone 6) Webcam

Describe common usage in your workflow

1) Shoot RAW 2) Develop the Raw image in Lightroom 3) Export/edit in Photoshop for retouching (PSD or TIFF format) 4) Retouch in Photoshop and save as PSD or TIFF (keep them!) 5) Save the ''flat'' TIFF (no layer) for high def. for clients or prints

Describe alternate/simplified workflow

1) Shoot RAW 2) Develop this RAW in Lightroom 3a) Export as TIFF or JPG for high def. for clients or prints 3b) Or export as JPG for low def. for screen or web usage

Miscellanous parts:

1) Sound card 2) Network card 3) Bluetooth card 4) Interface port 5) Power unit

What bits/channel is generally used for retouching?

16 bits/channel

How many color combinations does a 16 bits/channel have?

16 bits/channel has 65 536 tones per channel = Total possible tones are 281 trillions

1 bit has only

2 values

Let's take a grayscale image for example, how many colors are available per pixel if the image has 2 bits?

2 values for each bit so 2 x 2 = 4 colors available per pixel

Let's take a grayscale image for example, how many colors are available per pixel if the image has 3 bits?

2 values for each bit so 2 x 2 x 2 = 8 colors available per pixel

Let's take a grayscale image for example, how many colors are available per pixel if the image has 8 bits?

2 values for each bit so 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 = 256 colors available per pixel

If an image has a depth of only 1 bit how many values does she have? How many colors can she have per pixel?

2 values. That means the image can only have two colors per pixel. For instance, black or white.

What are 8 bits images also called?

24 bits images, because 8 x 3 is 24. Don't get confused!!!

8 bits/channel have how many values for each color?

256 values

How many color combinations does a 8 bits/channel have? Why?

256 x 256 x256 = Total of 16,8 millions colors

Describe TIFF format

A format half way between RAW and JPG. It can be opened with every graphic software so it's multiplatform. In that sense it's close to JPG but it contains so much more information. The file sizes are quite large. It allows layers and transparency. It's also ideal for retouching and print.

Network card:

Allows you to communicate over a network and with Wi-Fi connection

Describe the storage devices

Also called the secondary memory. Mainly what we call ''Hard Disk Drive'' and it's the computer's long time memory. It's where your software, programs and data are kept on a long term basis. It means that the data is still saved even if you turn off the computer or remove the power. Storage is greater than RAM but slower. Capacity is measure in GB (gigabytes) or TB (terabytes).

What is a computer?

An electronic device that manipulates information or data

What is software?

Any set of instructions that tells the hardware what to do

Why not using a simpler format straight away like jpg?

Because RAW format allows you to make your own decision instead of your camera such as sharpening, noise reduction, contrast and saturation

What do each values of R,G or B have?

Bit depth

What are the two kinds of images?

Bitmap and Vector

Describe a PSD format

Can only be opened by AdobePhotoshop so it's not multiplatform. Uses lossless compression always, so it has quite large files. Allows layers and transparency. An ideal format for retouching in Photoshot.

What are the two ways to use a format in your workflow?

Common usage and alternate/simplified workflow

What can software be divided into?

Computer programs (aka applications) and data

What can hardware be divided into?

Electronic and mechanical parts

What's the difference between input devices and output devices?

For input devices data flows into the computer, for output devices data flows out of the computer

What does the secondary memory include?

Hard drives

Computers use two different elements what are they?

Hardware and software

Efficiency and image quality will depend on the

Image format

What can pheripheral devices be divided into?

Input devices and output devices

What are some advantages of a RAW Format?

It has great dynamic range, color and detail info. It is ideal for retouching. You can never change or alter a RAW image because we can always come back to the original shot.

What's a resolution?

It's a density parameter

What does major hardware include? Where is the major hardware stored?

It's stored on the Motherboard 1) CPU/processor 2) Main memory or RAM 3) Video card or Graphic card

There are two types of compression algorithm, what are they?

Lossless or lossy

The unit for digital images is almost always the

Megapixel (millions of pixel)

The same image with a higher resolution means

More pixels fitted in one inch, therefore, a smaller print size but a higher quality

What's a density?

Numbers of elements per metric unit (concept mainly related to printing or scanning)

Digital images are divided into very small areas called

Pixels

Every color is a composition of

R,G,B

Each color is coded with 3 values corresponding with

R,G,B values

Describe RAM

RAM stands for Random Access Memory. It's the system's short term memory (main memory). It's where programs and data are kept when the CPU is actively using them. RAM is measure in Gigabytes (GB). The more RAM you have, the more things your computer can do at the same time, if not, your computer can become sluggish.

Describe a RAW Format

RAW format contains all of the information captured by the sensor. Not yet an ''image'' and needs to be developed. It's more of a description than an image.

Most common image formats are

RAW, TIFF, PSD, JPG, GIF, PNG

What are the primary colors called?

RGB and ''Channel''

Color images use three primary colors;

Red, Green and Blue

What's a lossless compression?

Reduces file size while preserving a perfect copy of the original uncompressed image. Results are in larger files. Should be used in the process of editing. Used for text, data files, audio and images.

What's a digital image?

Representation of a real image as a set of numbers that can be stored and handled by a digital computer

What's a lossy compression?

Representation of the original uncompressed image. May appear to be a perfect copy but is not a perfect copy. Reduces the quality and the results are in smaller files than the original. Often used for web, emails, etc.

What's color depth?

Represents the nb of bits used to code color shade, the amount of chromatic infor available for 1 pixel

Describe sound card:

Responsible for what you hear, manages audio input and output

Describe the graphic card

Responsible for what you see on the monitor. Has a processing unit , GPU (Graphics Processing Unit) and memory. It takes the load off the motherboard's CPU and memory to process images.

What are the two kinds of hard drives in modern computer?

SSD & HDD

Explain the difference between SSD and HDD drives

SSD drives are faster but with less storage capacity and more costly HDD drives are slower but with greater storage capacity and cheaper, also more fragile

Describe a PNG format

Stands for Portable Network Graphic. It's an open source alternative to GIF. Improved and non-patented, can handle transparency. Has lossless compression and limited use for photography.

Describe the CPU

The CPU stands for Central Processing Unit. It's also called a processor. It's the brain of the computer. It's job is to carry out commands so whenever you're doing something on the computer, you're sending instructions to the CPU. It also organises data exchanges between all different parts of the computer. A CPU's speed is measured in Hertz (frequency) or Gigahertz (GHz), which means billions of instructions per second. A faster processor can execute instructions more quickly

What format contains the most information?

The Raw format JP

Describe the motherboard

The motherboard is the main circuit board. It's a plate that holds CPU, RAM Memory, Graphic Card, Connectors for drives, Expansion cards to control the video, audio and network and lastly Connection to your computer's ports (such as USB ports). The motherboard connects directly or indirectly to every part of the computer.

What is hardware?

The physical parts of a computer

How many values does one each pixel have?

Three values, one for each primary color

What ability do computers have?

To store, retrieve and process data

Definition of an image

Total number of pixels that are contained in an image (which depends on the sensor size of the camera)

Describe Vector

Uses basic geometric shapes File size is less Possible to edit images without reducing the quality Suitable for logos, icons, clipart and abstract images Rather than a grid of pixels, a Vector graphic consists of shapes, curves, lines and text which together make a picture Some of their types are .ps, .eps, .svf, .ai, .cdr and .svg Their resolution is independent so they are resizeable without reducing the picture quality

Describe Bitmap

Uses pixels File size is more Possible to edit images to some extent Suitable for photographs Contains information about the color of each pixel Some of their types are .jpg, .gif, .tiff, psd Their resolution is dependent, so they are not resizeable without reducing the picture quality

Describe GIF format

Widely used on the web but mostly for logotypes. More performant than JPG for flat color and very poor at rendering photos. It can handle transparency. It has a lossless compression and copyright limitations.

Can image formats reduce the file size more or less?

Yes

Can a high definition image still not be good? Why?

Yes it can, because of blur, compression, poor lighting, poor composition and subject

In photography, only

bitmap files are used

Changing the resolution will never affect or change it's

definition (dimension)

Image formats organise and store

digital images

Everything you do on your computer will rely on both

hardware and software

Describe JPG format

has a lossy compressed format so loss of information and less information than in a RAW format. Every time you save a jpg image you increase the losses. It has a small file size and is very widely used and multiplatform. Can still be used for retouching but the possibilities are far greater with RAW format than JPG. They have no layers, no transparency. They're ideal for emails and web.

The definition of an image is often expressed by it's dimensions which are it's

height and width

For each pixel, it's brightness and colors are coded with

numbers

Numbers are arranged in an array of

rows and columns (x- and y-axis)

Image format is important because it impacts your

storage and computer resources

The greather the bit depth

the more tones can be represented

The size of the image depends on

the number of pixels in the image and the color