Image Storing & Transmission How are digital images formed and transmitted How do Pixels play a role in image quality

How Cameras Work The lens focuses light on the film/CCD chip When the button is pushed, a shutter opens for a split second Light enters and lands on the film/CCD chip The picture is recorded. Click on Hyperlink 

How Cameras Work

Get out the Books What do you know about digital cameras? How is the information stored in the camera? What are the benefits to using digital cameras? Open your textbooks to page Image Storing and Transmission Read page 239

Film vs. Digital Film uses a chemical reaction on paper that reacts with the light to form an image Digital cameras use special surfaces that react with light to create small electrical impulses The different electrical impulses are created by different colours Digital cameras use digits (numbers) to create an electronically stored image

What is Digital Digital information is stored as numbers in a specific order to create meaningful information This will make more sense when we talk about pixels

Get out the Books What do you know about picture elements? What are pixels? How do pixels form an image? Open your textbooks to page Image Storing and Transmission Read the first paragraph

What are Pixels? Pixels are small blocks of a single colour that combine with other pixels to form an image Pixels look like a checkered board of row after row of identically sized squares, each with its own colour

What are Pixels? PIXELS stands for “PICTURE ELEMENTS” To the right is another view of an image with the pixels enlarged Note that each pixel only contains one colour and one colour only Also note how many pixels are a very small space

Get out the Books What do you know about digital code? What info is needed to form a digital picture? How are digital pictures created? Open your textbooks to page Image Storing and Transmission Read the first paragraph

Digital Images & Pixels Combining the use of pixilated images and digital formatting, it is easy to see how pictures are created and stored digitally The 2 main components to each Pixel code are… 1) Each pixel is assigned coordinates in the grid just like an x – y graph to give it a location 2) Then that particular pixel is assigned a number that codes for that pixels colour.

Pixel Address

Digital Images & Pixels As you can see in this image, the each pixel has been given a number to represent the shade of grey it is supposed to be The lower the number, the darker the shade… the higher the number the brighter the shade

Get out the Books What do you know about picture quality? How do pixels affect picture quality? Open your textbooks to page Image Storing and Transmission Read the first paragraph

Image Quality & Pixels The higher the number of pixels a camera can collect light within a given area means a higher image quality More pixels = sharper image Higher Resolution = Better Image Quality

Image Quality & Pixels The image below is a perfect example of how more pixels equals better picture quality

Try This Exercise

2300 pixels7700 pixels1100 pixels11000 pixels Picture C is the lowest resolution with the least number of pixels and Picture D is the best resolution with the most pixels… the more pixels the better the resolution

Cropping Images The image gets worse because we aren’t increasing the number of pixels, just the size of the existing pixels

Get out the Books What do you know about coloured light? What do wavelengths affect? How does this aid in collecting digital images? Open your textbooks to page Image Storing and Transmission Read the first paragraph

Capturing Digital Images Any digital device uses CCD’s (Charge-Coupled Device) which is a light sensitive plaque made up of thousands of tiny light sensitive grids Light lands on this plaque to create different electrical signals

Capturing Digital Images Different coloured light = Different wavelengths Different wavelengths = Different energy levels Different energy levels = Different electrical signals Created by the CCD chip Different electrical signals = Different digital code

Get out the Books What do you know about transmitting digital images What other benefits are there about using digital images ? Open your textbooks to page Image Storing and Transmission Read the first paragraph

Transmitting Digital Images The biggest benefit of digital images is that they can be transmitted electronically, anywhere, really fast No photo development or hard copy to deal with

Brain Storming WHAT ARE THE BENEFITS TO USING DIGITAL IMAGING OVER CONVENTIONAL FILM?

Your Task!!! You are getting a worksheet that will be going over in two classes from now Use the sheet as a means of preparing for the unit end exam this information Note – The UNIT-END-EXAM is approaching rapidly