Activities‎ > ‎Investigations‎ > ‎Digital Images‎ > ‎

Pixel Count and Mystery Pictures

The number of pixels in an image tells you the picture’s resolution.
More pixels means a higher resolution,
allowing you to distinguish more details in the picture.

Materials

    DigitalImageBasics software can increase and decrease the resolution of the image,
    so that you can see how many pixels are necessary to recognize the picture’s subject.

    Download DigitalImageBasics.

What To Do...

  1. When you open an image in the "Pixels" tab panel of DigitalImageBasics, it will be at the lowest resolution: 2x2=4 pixels.

  2. Increase the number of pixels until you can make out what the picture is.

  3. In the table below, record the resolution needed to recognize the mystery pictures.

    At what resolution can you recognize the subject of the picture?

    What is the subject of this picture? Put answers on separate paper

  4. Read the page in "Basics of DEW" entitled What's a Pixel?
Mystery Picture #
At what resolution can you recognize the subject of the picture?
What is the subject of this picture?
     
     
     
     
     
     
     
     
     
     

Question: How does the resolution of an image affect what you can see?

    Why would you need more pixels to identify an image?

Question: When could you identify an image with large pixels?

    How does resolution affect interpreting satellite images?

Extensions

You may use DigitalImageBasics with any digital photograph – capture interesting (and free and non-copyrighted) pictures or take your own with a digital camera. Save any resolution to your computer and include in reports.