Download Ratio_Plus.class to the plugins folder,
or subfolder, and restart ImageJ.
This plugin calculates the ratio between two images (single frames or stacks),
as used in Fura-2 experiments, for example. The code -- heavily annotated to help
beginners like myself explore the world of ImageJ -- is largely based on Image
Calculator Plus. Paulo Magalhães, 10dec03.
The plugin requires two images of the same width and height,
and of the same type (8-, 16-, or 32-bit); the images must be:
i) two single images;
ii) two stacks with the same number of frames; or
iii) a stack as a first image and a single frame as a second - in this case,
the single frame will be applied throughtout the complete stack.
The resulting image (in 32-bit) is calculated as follows:
intR = (intA - bkgA) / (int B - bkgB) * MF
where intA, intB and intR are the intensities of the first, second and ratio images,
respectively; bkgA and bkgB are constant background values (entered by the user)
for the first and second images, respectively; MF is an arbitrary multiplication factor.
If a pixel value becomes negative after background subtraction, it is set to zero
before ratio calculation.
In addition, the plugin can accept clipping values for either of the images:
if the pixel intensity (after background subtraction) is lower than the clipping value
for that image, it is set to zero before ratio calculation; the clipping values for either
image are set by the user.
NB: if two corresponding pixels in the first and second images are zero, their ratio
is set to 1 (one); i.e., "zero by zero" division equals one.
background correction using a ROI (in one or both images).
Author: Wayne Rasband (firstname.lastname@example.org) Date: 2000/9/26 Requirements: Requires ImageJ 1.19h or later. Source: Background_Task.java Installation: Copy Background_Task.class to the plugins folder and restart ImageJ. Description:
Author: Wayne Rasband (email@example.com) History: 2001/02/21: First version 2001/12/17: 640×480 window, no drawImage scaling 2001/12/21: Displays frames generated per second in parentheses 2002/09/30: Pixels are