Region of analysis

The first step for analysing a sample is to choose the region to analyse. WinCELL can analyse the whole image or regions of any shape (first and second figure below). There can be practically an unlimited number of such regions, which can overlap or not. These can include just a few cells (such as the vessels of a ring), a complete ring or any region you wish such as the entire image minus some defects or bark. Regions can be rectangular, circular or irregular shape. Their positions can be saved to a file to be recreated on different images at a later time. Regions can be resized or moved and the analysis is updated automatically.

Ring Analysis

A special type of analysis region is provided to analyse annual rings. WinCELL can analyse cells per annual ring for one or more rings per image and compute statistics on a yearly basis in WinDENDRO's data format (compatible with stem analysis software programs such as XLSTEM) or in WinCELL's own format.

The annual ring analysis process is semi-automatic. Ring boundaries are first identified (boundary traced and year entered) then WinCELL closes those regions to create one analysed region per ring. The latter has all the usual wood cell measurements (area, length, width, position, perimeter, form....) plus the ring data (area, width) and can be done interactively or in batch (without operator supervision).

Data available per analysis region, image or annual ring are numerous and user selectable: Ring width, Ring area, Number of cells, Cell density, Total area occupied by cells and walls (in units or percentage of ring area), Average cells area, length, width, perimeter, form coefficient and more. These measurements are explained next.

Lumen and walls area are measured automatically and are a true measure of their area (based on the number of pixels contained within), not an estimation from the cell's diameter. Lumen can be separated into cells and vessels types based on their area and a third cell type, parenchyma, is available on a manual classification basis. Cells of different types are analysed separately (you get global and individual data for them). You can also change the classification of a cell interactively. Lumen and wall area are available as total values for the analysed region (in measurement units and in percentage area). Lumen area is also available per cell.

In addition to cell and wall areas, it can also measure the lumen and wall area in function of their color, globally for the analysed region or individually (per cell).

Tracheids length and width are available as average values for the analysed region and individually per cell. The length and width (or radial and longitudinal diameters) can be computed by 4 different methods:

Maximum (Horizontal & Vertical)
Length is measured as the horizontal distance between the two farthest cell boundary points of same vertical position. Width is the vertical distance between points on the same horizontal position.

Bounding Box (Horizontal & Vertical)
Length and width are measured as the horizontal and vertical size of the bounding rectangle that encompasses a cell.

Center (Horizontal & Vertical)
Length and width are measured as the horizontal and vertical size of the cell in its centre of gravity position.

Any direction
Length is the distance between the two points on the cell boundary that are the farthest apart and width is measured perpendicular to this length at the position where the width measurement is the largest. Walls are not calculated with this method.

There are four types of interactive measurements. In manual mode, no image analysis is done. It is provided to measure any object's length simply by clicking at its ends. It can be used to measure a cell length or as illustrated to the right, fibers length. Straight objects can be measured with two mouse clicks at their ends while curved objects can be measured with additional mouse clicks at inflection points along their curvature. Another manual mode is provided to measure an object length and width in pair (which can later be used to estimate its area). The latter can be used to measure cells which don't have enough contrast for the automatic analysis.

Two semi-automatic measurement modes allow to measure cells length and their two adjacent walls thickness (on opposite sides of the lumen). With one method this is done in the traced direction while with the other this is done in the radial direction. These two semi-automatic measurement modes also produce the length of radial cell rows (between annual ring boundaries to get ring width).