OPENING QUESTION:

 

LEARNING OBJECTIVE:  

• I will learn how to use a specific file editor to analyze an image file during today's class

WORDS FOR TODAY:

I STRONGLY URGE YOU TO START A DECK OF FLASH CARDS HERE

• Innovation: "A new or improved idea, device, product, etc, or the development thereof
• Prototype: "A proof of concept"
• CPU: Central Processing Unit
• Binary: 0's & 1's - Base₂
• Octal: Base₈
• Hexadecimal Base₁₆ - 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F
• Byte: one binary 'word'
• Bit: one binary 'letter' - either a 0 or 1, short for binary digits

WORK O' THE DAY: 

Consider the following logo from the world famous (but now defunct) Pam American World Airlines:

Recall your logo project-- somewhere in the logo is the information as to the size of the image (length and width and color depth) and hex and such?

After all if you bring up the image on your laptop it will default to a photo editing program?

Please discuss...

Now please use that solution to see if you can determine the file attributes for that logo

1. Here's the "widget"
2. Download that Pan Am logo to your laptop

 

 

 

 

 

 

 

 

1. Upload that Pan Am Logo to the hex editor at https://hexed.it/
2. Use the hex editor in combination with the widget to help you 'dissect' that logo. See how much information about the Pan Am logo you can get by interpreting the hex code.
3. Ok, so far so good, yay? <gulp> Now research jpg and png "headers". The good news is Code.Org often makes very complex tasks seem very easy. The bad news is that Code.Org often makes very complex tasks seem very easy.

It turns out the jpg 'header' information (the part of the jpg file that tells your computer that the file is, in fact, a jpg file) is rather lengthy. Take a gander at THIS

 

 

 

 

 

 

 

 

 

Sooooo... it turns out that THIS part of the file:

FF D8 FF E0 00 10 4A 46 49 46 00 01

Identifies the file as a jpg. *yikes*

With THAT in mind, take a DEEP Breath and

extra double kudos...

if you are brave enough to use THIS (I'll provide you printed color copies!)

to find the actual resolution (length/width) of the Pan Am Logo

Wow.... Substantially more difficult then the code.org widget would suggest.

We'll find that throughout the course, even with our javascript code generator that Code.Org frequently *abstracts* the real work by giving us widgets to use.

That's awesome in that it makes certain very difficult tasks very easy, but at the same time it often gives us the false impression that a tasque is easier then it actually is in the real world.

In previous years I had students *try* to research the file signatures for different types of files (.pdf, .jpg, .mp3 etc...). It turns out to be kind of a can of worms so I'll give that to you HERE