Exploring Picture Elements or Pixels with PixelView Software

Purpose: Explore how a picture would appear using different size pixels. 

Background: Pictures on a computer screen are made up of unique tiles, or pixels, of color. A picture element or pixel is the smallest area of constant color in a picture. The color of each pixel is controlled by the combined intensities of red, green, and blue components.

As you increase the number of pixels, you are not zooming into a picture. Rather, you are viewing a greater amount of detail in the image with the smaller pixels.

NOTE: The images that follow are not interactive. Please download the software (OSX OS9 PC) and follow along with the mini tutorial. 

Consider downloading the demonstration version since it includes 10 mystery pictures included in the programs interface (OSX OS9 PC).

Getting Started:

1) Select a picture (a file ending with ".jpeg", ".gif", ".tiff", ".pict", or ".pdf") by clicking 'Select Picture'. 

  • Use the pop-up window to select a picture available on your computer. 
  • The program works best on images with 512 pixels in both the vertical and horizontal dimensions (download a folder of mystery images that are this size: Mac PC).  
  • Images with significantly more pixels, say 7 megapixels or more, may be too large for this software, and an error message will be displayed. 
  • Images smaller than 512 x 512 pixels will have the edges filled with white.  This distorts the color of larger pixels along the edges since the white color will be averaged into the larger pixel’s color.

2) The first display of any picture will appear very blocky because only 4 pixels are used to create the picture.

  • Click 'Create Picture with More Pixels' to increase the number of pixels (and decrease the size of the pixels) used to view the picture.  The number of pixels increases by a factor of 4 with each click.
  • Click 'Create Picture with Fewer Pixels' to see the picture with fewer but larger pixels. 
  • To see the borders of pixels of different sizes, click on one of the options available in the menu button beneath the label 'Show Pixel Borders’.
  • Move the cursor across the picture, and the pixel being displayed will have a highlighted border, and the intensity of the pixel's color will appear in text in the lower left of the window. 

Special Features

Save each picture resolution using the 'Save Picture' option in the 'File Menu'. Remember to use a different filename for each resolution. In addition to creating your own mystery pictures, you can convert high resolution aerial photographs into images created by older satellite technology to compare what may be seen from different altitudes with different technologies.

Extensions

Test the resolution you can see with your eyes. Stand a distance away from your computer screen and have a friend change the resolution of the image being displayed on PixelView. At what point do you stop seeing more detail despite displaying the image with increasing resolution? You may also use the sequence of images at the Impact of Pixel Size .