Page 324 - Fundamentals of Light Microscopy and Electronic Imaging

CHAPTER
16

IMAGE PROCESSING
FOR SCIENTIFIC PUBLICATION

OVERVIEW

Image processing is often essential for preparing digital images for display where you
want the image to look good, and publication where you want an accurate record. When
these goals conflict, as they frequently do, we might ask if there are image-processing
standards to guide us in making key decisions. Unfortunately for the microscope com-
munity, there is no recognized set of standards, and the usual course is for individuals to
create solutions on their own. While many image-processing operations available in
popular software such as NIH Image or Photoshop can be performed in a photographer’s
darkroom, they are more easily performed digitally on a computer, tempting us to over-
process images. Figure 16-1 is processed in ways that give different interpretations
regarding the intracellular distribution of a fluorescent protein. Recognizing the need to
present the image in a nonarbitrary way, it would be useful to consider if image pro-
cessing guidelines are feasible and if they would help assure that images remain faithful
portrayals of their objects. In the author’s opinion, the answer to these questions is yes.
However, experts agree that attaining this goal is difficult because guidelines are con-
straining and inherently subjective. No single set of guidelines would be appropriate for
all images, and guidelines are to some extent arbitrary. Nevertheless, as electronic imag-
ing and image processing become indispensable in the laboratory, guidelines would
help standardize the way in which we present scientific images. It should be pointed out
that the main focus of this chapter deals with the processing of fluorescence microscope
images, a category that poses unique problems in the display of intensity, contrast, and
the use of color. However, in many places the guidelines are relevant to images obtained
by other forms of light microscopy. We begin by examining the significance and history
of processing in presenting microscope images.

IMAGE PROCESSING: ONE VARIABLE OUT OF MANY AFFECTING
THE APPEARANCE OF THE MICROSCOPE IMAGE

Consider the large number of factors that affect the quality and appearance of a fluores-
cence microscope image: 307