1° Color Morphology Analysis
In the first phase of the analysis, the image colors are analysed and quantified. It is used to differentiate objects from their background. Debris can be filtered out by different methods (see table below). In the second analysis phase, measurements are made on the detected objects and the whole image (or analysed region of it). These fall into three categories.
The histogram above the image can display the area per color class or group and, for the Pro version, the objects’ frequency distribution in function of a morphological measurement (Ex: number of objects of a certain area or length range).
Pixels are classified as a function of their color (Hue, Saturation and Intensity which is equivalent to Hue, Value and Chroma used in the Munsell color classification system). A tolerance factor for each of these component allow to include more or less colors in each class.
Note: You can get interactive information about analysed objects by clicking them in the image or look at the data files for more details. Measurements data are saved in text files that can be read by many programs (like Excel).
When you classify soils or plants by comparing their color to a printed set of reference colors such as the Munsell Soil Color Charts or Munsell Plant Tissue Color Chart, you are doing what we call an absolute classification. When you classify plant colors without comparison to an external reference, simply by comparing them you are doing what we call a relative color analysis. WinCAM NDVI works in the latter way. It classifies colors on a relative basis of what is contained in an image. It is possible in WinCAM NDVI to emulate an absolute color analysis by including in each image some reference colors (such as a subset of the Munsell samples). In that case, colors of the objects to analyse are compared to these reference color samples. This will work for as long as the number of reference color samples does not exceed WinCAM NDVI's limit of 36.
2° Spectral Vegetation Index Analysis (NDVI, Greenness)
WinCAM NDVI can compute six vegetation indices frequently used in agriculture and forestry healthiness/stress assessment (NDVI, ENDVI, EVI2, MSAVI, WDRVI, Green Chlorophyll) and you can also define you owns.
These images display the NDVI data using 3 different (false) color schemes. It was produced in WinCAM from the above NDVI camera image.
WinCAM NDVI can compute the spectral indices for the whole image, a region of it or per objects. It can also use the index values to classify them on different accept/reject criteria. Index data are available for these 3 types of analysis on screen and in data files (text based) and is also available in visual form as an index image with gray levels representing the index strength. These images can be saved for analysis or imported in different programs for multiple purposes (generate reports,...).
WinCAM NDVI can be used as a profilometer to analyse the gray levels (light intensities) or color variations along paths drawn by the operator over the image. Gray levels profiles can be saved in data files while color profiles’ data are saved as a summary of their color content (length in units and percentage of total path length per color). The profilometer can also be used to manually or semi-automatically measure objects dimensions by clicking them in the image.
4° Reflectance and Color Balance Calibration
It is possible to calibrate WinCAM NDVI so that it makes measurements in reflectance values or simply to balance the color channels. The former is done using known reflectance multi steps targets and the latter with a single white object. Both are available for the Visible and NIR spectrum. Calibration against know standards allows you to compare analysis data between images acquired with different cameras or camera settings (thus different lighting intensities for the same reflectance).
WinCAM NDVI Pro differs from the Regular Version by its ability
to analyse individual objects
The Pro version is required to analyse individual objects such as rice kernels (to measure their morphology, classify them in function of color or quantify the colors distribution per kernel).
The analysis of soil covered by plants as illustrated at 1° in the introduction can be done with the Regular or Pro versions. There are no objects to analyse in such images (only the classification of pixels into groups such as healthy vegetation, diseased vegetation and soil).
WinCAM NDVI is available in two versions
(Table below lists their respective features and measurements)