3D Reconstruction

The functions for 3D reconstruction as well as all the Image Filters are included in all of the X-Series programs.

 

Introduction

To be able to obtain the three-dimensional (3D) model of a surface it is necessary to have a sequence of partially in-focus images acquired with different focal planes (obtained by progressive steps).
The best reconstruction is obtained by acquiring the first image starting from the lowest plane.
The following images are obtained by rotating the microscope's focusing mechanism upwards trying to maintain a constant step between one image and the next.
Some microscopes have a motorized Z-axis and thus this operation may be automatic.

If images are acquired by a stero microscope lacking the tool for the correction of the angle of view, it is necessary to perform an alignment of the images.

AlIGNMENT OF STEREO IMAGES

Images acquired with a stereo microscope are slightly off-centered.
Acquire the image sequence starting from the lowest plane. The step between one image and the next must be selected so that the focus of the whole field of view is covered by the image sequence.
Once the sequence is acquired and the images are loaded, press  .
The animation of the aligned acquired images is dispayed.
The commands control the animation. Back one image, Forward one image, Play, Back to first image, and Stop. The alignment is automatic but you can correct manually the position of each single image.
If the animation shows an imperfect alignment, go to the image to be corrected and use the arrow keys on the keyboard. The corresponding position of the image in the sequence is displayed in X and Y coordinates on the Title Bar.
The performed correction can be verified by displaying alternatively the previous image and the following one with the commands.
 

Multifocus IMAGE

The construction of the multifocus image employs a maximum variance algorithm. The Surface Detail cursor acts on the kernel of the maximum variance filter. By increasing this value, the resulting multifocus image definition increases too, but so does the processing time.
The 3D Bilinear Filter acts on the three-dimensional model that will be created, correcting any zones which have failed to be in-focus in any of the images in the sequence. The higher its value, the higher the degree of softening of the 3D surface.
The button starts the construction of the multifocus image and the 3D model.

At the end the resulting multifocus image is displayed.
The last 3D model created is saved automatically and can be recalled at any moment with the 3D display button.

3D DISPLAY

The Vertical Dim. cursor controls the vertical dimension of the 3D model, while the Vertex Density controls the number of 3D points used for the construction of the 3D surface. To display the effect it is necessary to press the 3D display button.

The 3D display button allows you to display the 3D model, displays the reverse and displays it in the color scale.
On the model's lower surface is diplayed the reconstructed multifocus image, which can be useful for a 2D/3D visual comparison.

 

3D CONTROL

On the 3D window the left mouse button allows you to rotate the model wheras the right mouse button controls the translation.

The + (plus) and - (minus) characters on the numeric keypad control the zoom.

The Q and E characters on the keyboard control the camera's horizontal rotation whereas the A and Z keys control the vertical rotation.

 

The button performs a model rotation with respect to the vertical axis.

The button displays the model in its initial state.

The buttons control the storing in standard DirectX.

The button allows you to save the 3D image as a static image which can be useful, for example, to generate a professional report.

 

3D RECONSTRUCTION WINDOW

The 3D Reconstruction window menu, as well as containing the commands mentioned above, also contains the 3D Skeleton command which activates the vectorial display of the surface.