Northern Eclipse Help Reference

 Line scan measurement

The Line Scan function can be used to measure 1D gels or any application that requires the measurement of intensity under a line (this function is used in our DNA comet assay developed jointly by Empix Imaging and Princess Margaret Hospital). Once the Line Scan icon is clicked, the following menu appears.
When the Use Starting Line: check box is checked, a red and white dashed line is placed on the current image window (it defaults to the top of the current window) and may be pulled down the image to be used as a starting line for all side by side line scan measurements.


To enable this starting line feature click on Define button. Use the Horizontal bullet option if the starting line is for use in an east-west direction on the image (the Vertical bullet option for north-south). The Subtract Background check box option may be used if background noise or gray levels need to be subtracted from line measurements. Clicking on Define background allows the background line to be placed appropriately. Each pixel within the defined background line will be subtracted from all subsequent measurement lines drawn.  The Bright on Dark check box must be checked on for measuring white objects on a dark background. The default unchecked setting is for measuring dark objects on a light background. To draw a line scan, start at the red line and pull a line down with the left mouse button the required distance (Pull across if the Vertical option is being used). A Line Scan dialog box will appear in the Line Scan Graph window.

By moving the mouse on the Line Scan Graph, and holding down the left button, areas of the graph may be highlighted in yellow. This highlighting is used to specify the area (or band) for Data to be logged to excel. Once an area of the Line Scan Graph has been highlighted, only the data from that area under the graph will be logged to excel once the Log Data button has been clicked. If an area of the graph is not specified then all data under the graph will be logged once the Log Data button has been clicked. The Width adjustment control (spinner) on the Line Scan Graph dialog box allows the width of both the background line and the measurement line to be set to a desired pixel width. If the Width adjustment is set to a value higher than one, all values will be averaged down to a single line value in the horizontal or vertical direction, depending on which direction measurements are being made in.

See Also

Curvescan Measurement


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