Line Profile

Toolbar:

Menu:   Analysis > Line Profile

Script:   showProfile, setProfile, measProfile

Use this command to obtain the intensity values along the straight or freehand line and build the line profile plot for an active image. You can save the line profile data into a file and open it later, or you can export the results to Microsoft Excel for further analysis.

When you choose this command, the Line Profile window will appear. You can define the lines of the following shapes: horizontal, vertical, straight segment, ellipse, rectangle, and freehand. The profile shapes defined in each shape category are stored in the memory associated with an image. As you draw a new shape or reposition the existing one, the graph in the Line Profile window will be updated in real time and the statistics for the line profile displayed.

If you position the cursor over the line profile Graph and press the left mouse button, the crossing horizontal and vertical red lines will appear in the graph allowing you to interactively obtain the readings from the graph. You can have the line profile data presented in the calibrated or non-calibrated form. If both axes of the line profile graph are calibrated, the X-axis represents the spatial scale according to the current spatial calibration and the Y-axis measures the calibrated intensity values. See Histogram Preferences for more details.

If you activate another image, the line profile will be automatically updated for the shape associated with that image. If the content of the active image changes as a result of image processing, the line profile will be updated as well. That allows for line profile animation during the execution of real-time scripts.

You can change the size of the Line Profile window by positioning the cursor near an edge or corner and dragging the two-way arrow to the desired position.

When you choose the Line Profile command, the following options will become available:

New

Click this button to define a new freehand profile. The cursor will move to the active image and will take shape of a cross. Choose the appropriate place in the image, press the left mouse button, and drag the cursor to draw a desired line. If you want to add a straight segment to the freehand line, release the mouse button and move the cursor to the endpoint of the segment. If you want to constrain a segment to a vertical or horizontal line, hold down the CTRL key while moving the cursor. If you make a mistake, press the BACKSPACE key to remove the last segment. To finish the definition of the line, right click or double-click at the endpoint.

Shape

Lets you select the shape of the profile. Choose among the following options:

Horizontal

Sets the horizontal shape of the line profile. If you select this option, a horizontal line will appear across the active image. The arrow at the end of the segment indicates the direction of the line profile sampling. To move the segment, position the cursor over it, press the left mouse button and drag the segment to the desired location. You can also reposition the end points of the segment separately. To reverse the direction of the profile, double click the line.

Vertical

Sets the vertical shape of the line profile. If you select this option, a vertical line will appear across the active image. The arrow at the end of the segment indicates the direction of the line profile sampling. To move the segment, position the cursor over it, press the left mouse button and drag the segment to the desired location. You can also reposition the end points of the segment separately. To reverse the direction of the profile, double click the line.

Line

Sets the straight line shape of the profile. If you select this option, a straight segment will appear on the active image. The arrow at the end of the segment indicates the direction of the line profile sampling. To move the segment, position the cursor over it, press the left mouse button and drag the segment to the desired location. You can also reposition the end points of the segment separately. To reverse the direction of the profile, double click the line.

Ellipse

Sets the elliptical shape of the line profile. If you select this option, an ellipse will appear on the active image, with the arrow indicating the direction of the line profile sampling. To move the ellipse, position the cursor inside it, press the left mouse button and drag the ellipse to the desired location. To resize the ellipse, position the cursor over its boundary and move it to the desired location. To reverse the direction of the profile (clockwise versus counterclockwise), double click inside the ellipse.

Rectangle

Sets the rectangular shape of the line profile. If you select this option, a rectangle will appear on the active image, with the arrow indicating the direction of the line profile sampling. To move the rectangle, position the cursor inside it, press the left mouse button and drag the rectangle to the desired location. To resize the rectangle, position the cursor over its boundary and move it to the desired location. To reverse the direction of the profile (clockwise versus counterclockwise), double click inside the rectangle.

Freehand

Sets the freehand shape of the line profile. If you already defined a freehand line profile, it will appear on the active image. To move the freehand line, position the cursor over it, press the left mouse button and drag the line to the desired location. To reverse the direction of the profile, double-click the line. To define a new freehand line, choose the appropriate place in the image, press the left mouse button, drag the cursor to draw the desired line, then right click to finish the definition.

Channel

For a color image, click the arrow on the right of the Channel box and select the channel for which you want to build the line profile (Red, Green, or Blue for the RGB color model; Hue, Luminance, and Saturation for the HLS color model; I-Phase and Quadrature for the YIQ color model). A correspondent color intensity scale will be displayed under the histogram chart. If the active image is gray, the box will appear dimmed with Luminance channel selected.

Min, Max

Let you specify minimum and maximum for the intensity scale of the line profile Graph. By default, ImageWarp will set these values into 0 and 255 for a regular image, or into Display Range thresholds for a high-depth image. . If you want to change the vertical scaling of the graph, enter the desired values into these boxes.

>>>

Press this button to switch the Line Profile window into the Advanced View mode. The following controls will become available:

Count

Displays the number of the intensity points in the line profile array.

Mean

Displays the average intensity along the line.

Deviation

Displays the standard deviation of intensity along the line. Deviation represents how widely intensity values vary.

Minimum

Displays the minimum intensity along the line.

Maximum

Displays the maximum intensity along the line.

Graph

Check this box to display the line profile data in graphic form.

Table

Check this box to display the line profile data in tabular form

Smooth

Lets you select the mode for smoothing the line profile:

None

No smoothing is applied.

Lowpass

The lowpass filter (averaging) is applied to the array of intensities.

Gauss

The Gaussian filter is applied to the array of intensities.

Median

The median filter is applied to the array of intensities.

Width

Lets you select the window size for the smoothing filter. The bigger the window size is, the higher the degree of smoothing will be.

Copy to Grid   

Click this button to copy the line profile data to the Global Grid and display it. If the Global Grid already contains some data, they will be overwritten.

Save   

Use this button to store the current profile data to a file. Line profiles are saved as ImageWarp data tables containing the intensity values reported for each pixel of the line. When you press the Save button, the standard file dialog box will appear. Enter the name of the file to which you want the profile data stored, then click OK. Your profile data will be written to the file.

Export to Excel   

Press this button to export the histogram data to Microsoft Excel's spreadsheet. You should have Microsoft Excel installed in your system in order to utilize this command.

Copy   

Click this button to copy the current line profile graph and statistics to the Windows Clipboard. After this you can paste the graph into other applications that accept standard clipboard formats. You can also press CTRL-C or CTRL-INS to perform this action.

Print   

Click this button to print the histogram and statistics data.

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Press this button to switch the Line Profile window into the Standard View mode.