of the microscope
The zoom is calculated
with a cubic B-spline interpolation for zooming in and by linear
interpolation, after an anti-aliasing filter (averaging filter),
for zooming out.
For 2D images, the
focus is simulated by a gaussian filter.
For 3D images we
have an in-focus plane of the object, the other planes are more
or less blurred. To simulate that, a z coordinate is given to each
point of the image, according to a chosen function, then the difference
of "altitude" is done between the in-focus plane and the
z coordinate of each point. The blurring is made with a Gaussian
filter, with the variable sigma depending on the difference previously
The light intensity
is obtained by adding or substracting a constant set by the user
to every pixel value.
A linear function
is used to define the contrast : y = mx + h, x is the old pixel
value, the slope m is chosen by the user and controls the strength
of the contrast, h is calculated to keep the function centered on
(127.5, 127.5), and y is the new pixel value. The values under 0
are set to 0, and the ones over 255 are set to 255.
interference contrast is a good tool to detect low contrast objects.
It is simulated by a steerable 2D Gauss function derivative.