Images appropriate for analysis
This means that the analysis is meaningful only when the image can be interpreted as 2-dimensional.
Examples of appropriate images are:
- cells, cellular tissue, or blood cells under microscope,
- fingerprints and some other biometrics,
- maps and satellite imaging,
- logos, paintings, and other visual work,
- and many many more.
In inappropriate images the third dimension is essential. They may contain:
- occluded objects,
- objects well lit on one side and very dark on the other,
Mugshots may serve as an example of appropriate images of 3D objects because they are always taken under same angle with similar lighting. For the same reason, applications in machine vision for industrial inspection are also appropriate. Detecting a change in a 3D scene (appearance of a person in a security camera) is also feasible.
Images of 3D objects may contain 2D items: text, scratches, other imperfections of the photograph or the lenses, noise, etc.
First, it may be impossible to separate objects such as particles. Even though two particles may seem distinct to you, if you zoom in, you might see a thin bridge between them. As a result the software thinks this is the same particle.
Pixcavator does not treat two objects as one, no matter how close they are. For example, these are inappropriate images:
- a thin scratch on the photo will cut an object in two,
- person's shirt and pants (of different color) will cut him in half,
- the background of an object is uneven and has colors similar to the one of the object.
At this time these tools exist as a way to modify the image prior to analysis. These "morphological operations" aren't integrated in Pixcavator yet. Nor are watershed algorithm and similar.