image = dicIntegration2dImg (inImg,inStdDev,theta)

Detailed Description

Differential Interference Contrast (DIC) line integration along a given orientation on 2d images.

This algorithm enhances objects from Differential Interference Contrast (DIC) like images. The idea is to reconstruct the objects from their gradient by accumulating the intensities along the gradient direction.

The figure below illustrates this principle:

The process is deomposed in to the following steps:

First high-pass filter
Integration along an orientation InTheta (in radians), provided as an input parameter
Second high-pass filter

The highpass filters consist in the subtraction between the image $I(\textbf{x})$ and its blurred version $I_b(\textbf{x})$ :

$I_H(\textbf{x}) = I(\textbf{x}) - I_b(\textbf{x})$

where $I_H(\textbf{x})$ is the result of the high-pass filter at position $\textbf{x}$ and $I_b(\textbf{x})$ is the image $I(\textbf{x})$ blurred by a 1D Gaussian smoothing with a standard deviation InStdDev and an orientation of InTheta.

The following figrue shows a simple example of the kind of result expected the DIC integration filtering:

If the integration direction matches the opposite of the gradient orientation, objects will appear dark instead of bright:

Note: It is recommanded to use a standard deviation higher or equal to the objects' half-size.

Here is a example of result on a real image:

In practice, the blur may alter the result because the gradient do not cancel itself along the integration line. It can be caused by a difference between the integration direction and the actual gradient direction. It can generates linear artefact in the integration direction.

This effect can be removed by oriented morphological operation or an oriented VSNR.

Finally, keep in mind that the result of the DIC filter does not allow to correctly segment the objects, because their shape is degraded, but it allows a good identification.

Example of Python code :

Example imports

import PyIPSDK

import PyIPSDK.IPSDKIPLFiltering as filter

Code Example

    # opening of input images
    inImg = PyIPSDK.loadTiffImageFile(inputImgPath)
    
    # Calculation
    outImg = filter.dicIntegration2dImg(inImg, stdDev, theta)

Example of C++ code :

Example informations

Header file

#include <IPSDKIPL/IPSDKIPLFiltering/Processor/DicIntegration2dImg/DicIntegration2dImg.h>

Code Example

        // opening input image
        ImagePtr pInImg = loadTiffImageFile(inImgPath);
        
        // compute the oriented integration
        ImagePtr pOutImg = dicIntegration2dImg(pInImg, stdDev, theta);