Mask Creator

Command:

Context Menu: Create a Mask from Current Image Data

The mask creator is an easy to use tool which allows to create pixel masks from numeric image data. The data matrix is displayed both as an image (left panel) and as a histogram (right panel) and can be any kind of image data - from a simple layer of the hyperspectral cube to residuals of a model. In addition the user can select an existing mask to mask out certain pixels when calculating the histogram. The pixels covered by this mask are indicated in pink color.

The histogram visualizes the distribution of the values of the data matrix. Within the histogram you can move two vertical cursors which define two thresholds. All pixels which fall below the lower threshold are indicated in red, all pixels showing a data value greater than the upper threshold are displayed in blue, pixels between the two thresholds are left unchanged. You can adjust the thresholds by dragging the corresponding cursor lines over the histogram. Above the histogram there is a table which shows the number of pixels assigned to each of the four regions. You can select which of the three regions of the histogram are used for creating a mask by ticking the corresponding checkbox in the column "mask". The area of the selected mask (pink area) can either be included in the generated mask or excluded from it.

When you click the "Create Mask" button the pixels of these selected regions are copied into a newly created mask.

Currently the mask creator is available from the context menus of the following tools:

• Chemical maps
• Principal Component Analysis (PCA)
• PLS based Discriminant Analysis (PLS/DA)
• Random Decision Forest
• 2D Imager
• Similarity Map
• Regression of Layers
• Vertex Component Analysis (VCA)
• Fuzzy c-Means Clustering
• Time Delay Map
• Spectral Descriptor Editor

How To:

Right-click the image whose numeric data should be used as the basis for calculating the pixel mask and select the command Create a Mask from Current Image Data. This opens the mask creator tool. Adjust the threshold (blue and/or red). When the masked area fits your needs, click "Create Mask" and enter a name of the new mask. Hint: the created mask can be further edited and processed using the mask editor.