WinCAM NDVI Analysis System
Image Analysis for Plant Science
img0
Regent Instruments Inc. since 1991

 

 

WinCAM NDVI

For sales informations,
contact us by email

sales@regentinstruments.com
WinCAM, NDVI, color analysis, measurement, CAM, color area meter  
WinCAM NDVI Measurements
1° Color Morphology Analysis

In the first phase of the analysis, colors or grey levels are used to differentiate objects from their surrounding 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. These fall into three categories.

  • 1) Global measurements related to the analysed region such as total and percentage area occupied by objects and their average morphological measurements (area, length, width...). Color aggregation is also in this group.
  • 2) Individual morphological measurements such as area, length, width, perimeter and form coefficient.
  • 3) Area in function of color, NDVI or Color Index. For each object and the analysed region, you get the area occupied by each color of interest and groups of them. This also includes information about the dominant color.
This histogram can display the area per color class or group and for the Pro version the object frequency distribution in function of a morphological measurement (Ex: number of objects of a certain area or length range).
WinCAM, NDVI, color analysis, measurement, CAM, color area meter
WinCAM, NDVI, color analysis, measurement, CAM, color area meter
WinCAM, NDVI, color analysis, measurement, CAM, color area meter
WinCAM, NDVI, color analysis, measurement, CAM, color area meter

The original image to analyse is a 24 bits color image which can contain millions of colors (it is not limited to 256 as in some competing programs). Images in such format are easily obtained with current digital cameras and scanners. This image contains all the scene fine color variations that the human eye is accustomed to.

Note: The image can also be a 256 gray levels image.

Before analysing a series of images, you must teach WinCAM NDVI which colors are part of the objects to analyse (the grass, fruits, disease or healthy regions) and which ones are not (the background such as the soil) simply by clicking the image and giving names to these clusters that we call color classes. In the first phase of the analysis, WinCAM NDVI will classify the image pixels into one of these classes that you have defined (special processing is provided for those who do no match any criteria). The result of this classification can be displayed and saved to files. Color classes can be grouped, the group can be given a name and area measurement data can be obtained per color class or group. In the above example, the Grass group is made of four green colors and the soil two brown colors.
The classification into groups can also be displayed and saved to files. There can be up to three groups and each one can have up to twelve color classes.
Example of color classes to analyse the soil cover image to the left.
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.
Pixels classification into Hue, Saturation and Intensity can also be displayed on screen and exported to tiff files.
WinCAM, NDVI, color analysis, measurement, CAM, color area meter
Color image
One of these channels, as well as the Red, Green or Blue channel can also be displayed and analysed instead of the original color image.
WinCAM, NDVI, color analysis, measurement, CAM, color area meter
Red channel
WinCAM, NDVI, color analysis, measurement, CAM, color area meter
Green channel
WinCAM, NDVI, color analysis, measurement, CAM, color area meter
Blue channel
WinCAM, NDVI, color analysis, measurement, CAM, color area meter
Hue
WinCAM, NDVI, color analysis, measurement, CAM, color area meter
Saturation
WinCAM, NDVI, color analysis, measurement, CAM, color area meter
Intensity
     
WinCAM, NDVI, color analysis, measurement, CAM, color area meter WinCAM, NDVI, color analysis, measurement, CAM, color area meter WinCAM, NDVI, color analysis, measurement, CAM, color area meter
WinCAM NDVI can be used to quantify toasts (slices of bread) baking uniformity and consistency over time.
The image of colour classes. It shows into which color class each pixel has been classified.
Colour classes and groups defined
to analyse the toasts baking.

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 most data analysis or spreadsheet style programs (like Excel).

2° Color and Vegetation Index Analysis (NDVI, Greenness)

WinCAM NDVI can compute two vegetation indexes frequently used in agriculture and forestry healthiness/stress assessment.

- The NDVI (Normalized Difference Vegetation Index) is a measure of plant healthiness and quantity. It requires one image with both channels of a scene, one in the NIR (near-infrared) and one in the Visible. Such images can come from aerial or ground based image acquisition with special or modified conventional cameras such as our NDVI camera. The index highlight the strong reflectance of healthy green plants in the NIR (due to mesophyl cells scattering light at that wavelength) compared to the low reflectance in the Visible (due to the chlorophyll high absorption). Dry or inactive vegetation and soil, rocks, water do not exhibit this spectral behavior. NDVI images and data can be created interactively or in batch (without operator supervision) from NIR and Visible images stored in a folder.

WinCAM, NDVI, color analysis, measurement, CAM, color area meter
WinCAM, NDVI, color analysis, measurement, CAM, color area meter
WinCAM, NDVI, color analysis, measurement, CAM, color area meter
RGB color image
Greenness index image
Color classified image
- The Greenness quantifies the amount of green in a standard color image. It is an index which has positive values when green is present and zero or negative when it is not. It is frequently used in soil vegetation cover analysis.
WinCAM, NDVI, color analysis, measurement, CAM, color area meter WinCAM, NDVI, color analysis, measurement, CAM, color area meter WinCAM, NDVI, color analysis, measurement, CAM, color area meter WinCAM, NDVI, color analysis, measurement, CAM, color area meter
This image was acquired with a conventional color camera (not with our NDVI camera) This image was acquired with our NDVI camera. Its Red channel contains the NIR data while the Blue one contains the visible Blue channel data. This image displays the NiR channel data. It was produced in WinCAM from the NDVI camera image. This image displays the visible blue channel data. It was produced from the NDVI camera image.
WinCAM, NDVI, color analysis, measurement, CAM, color area meter
WinCAM, NDVI, color analysis, measurement, CAM, color area meter
WinCAM, NDVI, color analysis, measurement, CAM, color area meter
WinCAM, NDVI, color analysis, measurement, CAM, color area meter
This image displays the NDVI data using a gray scale (white = high NDVI value, Black = negative values). It was produced in WinCAM from the above row NDVI camera image.
These images display the NDVI data using 3 different (false) color schemes. It was produced in WinCAM from the above NDVI camera image.

- You can also can define your own color index as a mix of an image RGB (Red, Green or Blue) channels or the ratio of two such mixes. Color indexes images and data can be created interactively or in batch (without operator supervision).

WinCAM NDVI can compute the NDVI, Greenness and other color indexes for the whole image, a region of it or per objects (when they contrast with their background). It can also use these values to classify them on different accept/reject criteria. Index data is 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,...).

3° Profilometry

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 mm or other units] and percentage of total path length per color).

- The profilometer command 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 different images acquired with different cameras or camera settings (thus different lighting intensities for the same reflectance). It also allows to compensate for non linearities of the image acquisition process (CCD or CMOS sensor, electronic gains, image processed). This is important for precise index and profilometry analysis.

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 (such as when determining which ones are darker green and which one have a yellowish tint), you are doing what we call a relative color analysis. WinCAM NDVI works in the latter way, that 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 targets. This will work for as long as the number of reference classes do not exceed WinCAM NDVI's limit of 36.

WinCAM NDVI Pro differs from the Regular Version by its ability
to analyse individual objects
The Pro version is required to analyse individual rice kernels morphology or to classify them in function of color (colors distribution per kernel).

The analysis of soil covered by plants as illustrated at in the intro can be done with the Regular or Pro versions. There are no objects to analyse in such images (only the classification of pixels into two groups, each having one or more colors). With both versions you can analyse the whole image or simply outline the region you wish to be analysed
WinCAM, NDVI, color analysis, measurement, CAM, color area meter
   
WinCAM NDVI is available in two versions
(Table below lists their respective features and measurements)
Measurements
Reg
Pro
Description
Analyse whole image or sub-region of it
Y
Y
Measure areas in function of color for whole image or a sub-region of it of any shape. Rectangular and circular are pre-defined shapes. Create any irregular shape regions with the lasso tool (outline their boundary by drawing in the image). You can move and resize regions which have been analysed.
Individual objects morphology and color analysis
N
Y
Analyse non-touching objects morphology and color on an individual basis. Measure the objects length by 4 methods, width, perimeter, form coefficient, length/width ratio, object area, area per color and information about dominant color. Objects presence and how measurements have been done on them can be indicated by different symbols over the image.
NDVI
Y
Y
Normalized Difference Vegetation Index. A commonly used vegetation index.
Greenness
Y
Y
A commonly used vegetation index. Quantifies the amount of green.
User definable Color Index
Y
Y
You can create your own color indexes or add other known indexes but not built-in WinCAM NDVI.
Objects classification
N
Y
In function of color area, ratio of colors, color index, NDVI or Greenness.
Profilometer
Y
Y
To record and analyse the gray levels (light intensities) or color variations along paths drawn by the operator over images.
Debris filtering based on morphology
N
Y
Remove debris based on anatomical properties like area, length, width, length/width ratio and form coefficient.
Debris filtering based on color
Y
Y
When debris have a different color than the objects to analyse, this function can be used to exclude them from the analysis
Analyse gray levels or color images
Y
Y
Analyse the colors of a color image or the luminosity in gray levels image. Color or gray level information can be used to separate pixels belonging to objects and background.
View/Analyse/Export RGB channels
Y
Y
From a color image, choose its Red, Green or Blue component to be displayed on screen, analysed and saved to a standard tiff file.
View/Analyse/Export HSI channels
Y
Y
From a color image, choose its Hue, Saturation or Intensity color information channel to be displayed on screen, analysed and saved to a standard tiff file. The HSI components are equivalent to Munsell's Hue, Value and Chroma components.
Exclusion regions
Y
Y
Exclude from the analysis any sub-region of any shape of the image. Can be used to remove debris or to avoid areas which must not be analysed.
Batch analysis
Y
Y
Analyse images without operator supervision. Note: Images which require operator intervention for calibration cannot be analysed in batch.
Interactive pixels classification adjustment
Y
Y
Allows to make modifications to the automatic pixels classification (into object and background) based on color or gray levels in specific regions or the image (any shape) or the whole image.
Analysis can be stopped
Y
Y
Simply press a keyboard key while the analysis progress bar is displayed.
Keep or reject incomplete objects
Y
Y
Prevent objects truncated by image boundaries from being analysed and affecting average measurements.
Features,
Reg
Pro
Description
Pixel size calibration
Y
Y
For images from camera, pixels size must be determined by calibration to produce measurements in units of your choice (mm, cm, inches...). With Regent's targets (see Field Image Acquisition Kit below), all is needed is a mouse click on the target in the image.
White balance calibration
Y
Y
To remove color variations due to changes in lighting or camera settings between images. With Regent's targets (see Field Image Acquisition Kit below), all is needed is a mouse click on the target in the image.
Multi steps reflectance calibration
Y
Y
Reflectance calibration can be done using multi-steps targets to get reflectance measurements data and image.
Remove background light variations
Y
Y
For images acquired with a camera when background light has variations which can affects the analysis. Note: It is best to invest time in having a uniform lighting. The analysis will be faster and easier.
,
Image edition
Y
Y
To remove debris or artefacts. Can also be used to make corrections to pixels classification (into object and background), to trace over objects to analyse (when this is not possible automatically) or to separate touching objects. You can edit with predefined colors or pick those already present in the image.
Interactive measurements/Number of methods
Y/1
Y/2
Interactive measurement is a way of measuring objects manually (both versions) or semi-automatically (Pro version) when the automatic analysis cannot do exactly what you want to measure. In semi-automatic mode, simply draw a line over an object at the place you want it to be measured and WinCAM NDVI will automatically find the object's boundary beginning and ending over that line and measure the length in between (it will also measure the traveled distance).
Histogram of frequency distribution
N
Y
Display the number of objects that fall into classes of morphological features (Ex: number of objects with an area between 1 and 2 square mm).
Histogram of color distribution
Y
Y
Display the area covered by each color class or group in the analysed region or image.
Extract GPS data
Y
Y
WinCAM NDVI will automatically extract GPS data (Latitude, Longitude, Altitude, Direction, Date, Time) when they are present in tiff or jpeg files. These data will also be saved with the measurements data.
Display image data under mouse cursor
Y
Y
WinCAM NDVI now displays in the Information area (above the image) the pixel value at the mouse cursor position in the image. The data written depends on the image displayed. It can be; the RGB, Gray levels, Hue, Saturation, Intensity or Color index/NDVI value.