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Figure 13. Harmon’s Version of a Famous
Figure 12. 80 Pixels, but not an Image.
Face.
Source: Harmon, 74; Bloomer, 118; Ivry and Robertson, 119
As the number of pixels increases, shown enough of the display simultaneously, the
viewer’s intellect perceives more than the sum of the details and creates an image. Most
students can make this mental leap when they view “Harmon’s Version of a Famous
Face.” When someone perceives the object, they know they see it. As Solso writes “It
cannot be explained, but when attained cannot be confused.” 186 Harmon found that his
test subjects could perceive a pixelated print even more clearly when they squinted their
eyes or viewed the print from a distance — either of which accentuates the scene’s whole
while reducing the prominence of the details (try this with Figure 13). 187 Contrast the
effectiveness of this demonstration with the futile attempt on page 65 to describe an
“image” with text.
After demonstrating the nature of an “image,” the course takes a step backward to
employ line-drawings of optical illusions that demonstrate visual principles. It was a signals
student who first suggested the author use optical illusions as an analogy for image
research. Having come to the teaching job directly from imagery analysis, the author’s
first classes were far too visual. While line drawings appear crude to professional interpreters,
they are ideal for teaching nonpractitioners, and the course now incorporates
many of the classics: The Kanizsa Triangle demonstrates the subjective nature of seeing.
186 Solso, 256.
187 Harmon, 71, 76. Bloomer, 118, and Ivry and Robertson, 199, both more recently republished Harmon’s
print. For other examples see William J. Mitchell, 68-77.
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