Computing Fundamentals Lesson 5 – Dotty Reality This lesson you will be discovering how computers save picture files, using dots and points.

Find out how computers save picture files in a computer.. Understand how to change pixels of an image, to encode hidden data within that image. Learning Goals Surface Learning Deep Learning Computer Fundamentals Lesson 6- Dotty Reality In this lesson you will… Explain how a picture is broken down into pixels which are then used to assemble the complete picture.

Starter HPE HPE How does the computer put the person inside it? How does this relate to how computers digitise pictures?

Can you find the hidden data? I have hidden data in the pixels of this picture. Download it from teachcompsci, put it in paint and try to decode it!

How do you think it was done? Must use bitmapped file (.BMP) as needs to save each pixel Task! – Use paint, come up with your own key and an image to use, and create pictures with hidden messages in them.

Try to… Having created your own key and coded picture, see if you can get somebody else to decode your encoded data. (Look at your picture, zoom in, and try to find your hidden message)

Find out how computers save picture files in a computer.. Understand how to change pixels of an image, to encode hidden data within that image. Learning Goals Surface Learning Deep Learning Computer Fundamentals Lesson 6- Dotty Reality In this lesson you did… Explain how changing the number of dots in a picture changes the nature of the picture..

Homework Create another hidden message at home, upload the final message and the key to the intranet.