CONVERTING
PIXELS TO MICRONS
In the microscopic world, the most common units of measurements
are the micrometer (micron), and the
nano-meter. The micron is one millionth of a
meter, and the nano-meter is one billionth of a meter. However, in
the field of digital images, the pixel is the basic
unit of measurement. Therefore, if we want to measure the
dimensions of an object of interest, within a digitally captured
microscopic image (micro-graph), we need to convert
pixels to microns.
Most good image manipulating programs, include a measuring
tool that allows us to measure (in pixels) the distance between
any two selected points of an image (a micro-graph in our case).
The GIMP (Gnu Image Manipulation Program) is one of those
programs. Here is an example, of using the GIMP's measuring tool,
to measure (in pixels) the diameter of a red blood cell.
The measuring tool indicates that the distance between the 2
selected points is 203 pixels. However, we need the distance in
microns. I know that the image was captured by a Nikon camera at a
resolution of 2992x2000 pixels and at a microscope magnification
of 1000x. So I look at the conversion tables for the Nikon, and it
indicates that I need to divide the measured pixels by 27 in order
to convert the value from pixels to microns. So I divide 203 by 27
and get 7.52 microns.
The pixels-to-microns conversion tables, are an easy way to
convert pixels to microns. I have created 2 conversion tables, one
for each of the 2 digital cameras that I use with the microscope.
I am including, on this web page, links to the 2 tables. Each
table is available in PDF and HTML formats. The tables have
conversion factors for each combination of camera resolution and
microscope amplification.
Link to
Conversion Table (in HTML format) for the AmScope MU300
microscope digital camera.
Link to
Conversion Table (in PDF format) for the AmScope MU300
microscope digital camera.
Link
to Conversion Table (in HTML) for the Nikon D-3500 digital
camera (with a 10x microscope lens).
Link to Conversion Table (in PDF)
for the Nikon D-3500 digital camera (with a 10x microscope
lens).
If you are using a camera with different image resolutions, then
you need to create a conversion table for your camera. The
methodology for creating the conversion tables is very simple.
Bellow is a link to step-by-step procedure for creating the table.
CREATING A
PIXELS TO MICRONS CONVERSION TABLE
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