Thermalyze Operation


Graphs

The topics in this section explain how to create a number of graphs including line profiles, histograms, and strip charts.

Slow Capturing: Graphing and charting consume significant computer resources and image capture rate may decrease when graphs and charts are displayed.  Consider selecting a lower update frequency on the top toolbar of each window or close all unnecessary graphs and charts while capturing images.  After images have been captured or image sequences have been recorded, open the graphs and charts for post-analysis..  If image capture rate falls, follow the suggestions in the Introduction to increase processing rate.

Line Profile

Description

The Line Profile graph displays real-time temperature data along the pixels of a Line Region.  To open the Line Profile window (see Figure 1), select the Line Profile item from the Graphs menu or press the  button on the Shortcuts toolbar.

Figure 1: Line Profile window

Create a Line Profile

To create a Line Profile graph, draw a Line Region and then select the Region index on the top toolbar of the Line Profile window.  The x axis displays the pixels along the Line Region.  The value of zero on the x axis indicates the first pixel of the Line Region.  If the Line Region is drawn from left to right on the image, the Line Profile will be displayed in the same orientation.  If the Line Region is drawn from right to left however, the Line Profile will be displayed in reverse orientation.

Adjust the X and Y Axes

Hover over the top half of the graph and use the mouse scroll wheel to change the y-axis max value.  Hover over the bottom half to change the y-axis min value.  Hold down the Shift key while scrolling and hover over the left (right) half to change the values of the x-axis min (max).  Hold the Ctrl key while scrolling to change values by a smaller increment.

You can also click the Zoom Out Completely button  to set the x-axis and y-axis ranges to the bounds of the data.  Set the Auto Range New Data button to  to automatically reset the x-axis and y-axis ranges to the bounds of the data each time new data is displayed.

File Menu

Export Window
The Line Profile window can be saved to file in the following formats: bmp, jpg, png, and tif.  The size of the exported image is proportional to the size of the Line Profile window.

Note: Exported Line Profile windows are saved in the "Optotherm\Thermalyze\Export" folder unless you specify a different folder.
Export Temperatures
The pixel temperature values in a Line Region can be saved to file in ASCII text format with ".txt" extension.  Starting with pixel index 0, the pixel index and then the pixel value are saved to file separated by a tab character.  Pixel temperature values are saved in units of degrees Celsius (for example, 24.78).  A newline character (carriage return/line feed) separates each pixel index/temperature pair.

Note: Exported pixel temperature values are saved in the "Optotherm\Thermalyze\Export\Line Profiles" folder unless you specify a different folder.
Print
Print the Line Profile window.

Note: You must have a printer connected to your computer.
Print with Preview
Select this menu item to open the Print Preview dialog before printing.

Toolbar

Region Index
Select the index of the Line Region to display.
Update Frequency
Select the frequency to update the data in the graph.  Select max to update the graph each time new data is available.
 Freeze Updates
Press this button to temporarily freeze graph updates.
 Select
Select this button when finished zooming or panning to allow placement of the vertical cursor on the graph.
 Zoom In
Select this button to zoom into the graph.  Click and drag on the graph to select a rectangular area to zoom into.
 Zoom Out
Click this button to zoom out of the graph one level.  Continue clicking this button to zoom out additional level.
 Zoom Out Completely
Click this button to set the x-axis and y-axis ranges to the bounds of the data.
 Pan
Select this button and then click and drag on the graph to pan.
 Auto Range New Data
Press this button to automatically reset the x-axis and y-axis ranges to the bounds of the data each time new data is displayed.

Line Measurement

The Line Measurement fields display the length on the target that corresponds to the Line Region.  By placing the beginning of a Line Region at a reference location on the target (such as a corner or through hole) and the end of the Line Region on a pixel of interest, the precise location of pixel can be determined.

Pixel Size
Enter the pixel resolution of the currently installed lens.  Pixel resolution is the width of each square area on the target that is imaged onto a single detector pixel. When a fixed focus lens is installed and the Measure Distance window is opened, Pixel Size is set equal to the pixel resolution of the installed lens.  Values range from 0.001 to 1000.

Fixed focus lenses have a set pixel resolution that is listed in the lens specifications.   When using a focusable lens, the pixel size will vary and will depend on the angular field-of-view of the lens and the distance from the lens to the target.

Tip: Units of length are not displayed for Pixel Size or Line Length.  Therefore, you must use units so that Pixel Size is within the valid range of 0.001 to 1000.  Convenient units to use that will accommodate this range are microns, mm, or mil (0.001"). 
Line Length
This field displays the length on the target that corresponds to the Line Region.  The units are the same as Pixel Size.
Calculate Pixel Size for a Focusable Lens
  1. Position the camera to view the target and then focus the lens.

  2. Place a metal ruler or other object of known length in front of the camera so that it nearly fills the camera’s horizontal field-of-view.

  3. Draw a horizontal Line Region the same length as the ruler and note the value in the Area column of the Region Data Grid.  This value is the length of the Line Region in pixels.

  4. Calculate Pixel Size by dividing the length of the ruler by the Area value.  Note: You may need to scale the units of Pixel Size so that it is within the range of 0.001 to 1000.

Cursor Info

The Cursor Info fields display the pixel location and temperature at the cursor location.  Click a point on the plotted line to set the cursor location.

Temperature
This field displays the temperature on the Line Region at the cursor location.
Position
This field displays the location of the cursor on the Line Region in pixel coordinates.

Histogram

Description

The Histogram graph displays the real-time temperature distribution of pixels within a region.  To open the Histogram window (see Figure 2), select the Histogram item from the Graphs menu or press the  button on the Shortcuts toolbar.

Figure 2: Histogram window

Create a Histogram

To create a Histogram graph, draw a region and then select the region index on the top toolbar of the Histogram window.  Histogram data is calculated by dividing the range of pixel temperature value within the selected region in 256 equal temperature intervals.  The y axis displays the number of pixels in the selected Region whose temperature lies within the temperature interval whose center value is displayed on the x-axis.

Adjust the X and Y Axes

Hover over the top half of the graph and use the mouse scroll wheel to change the y-axis max value.  Hover over the bottom half to change the y-axis min value.  Hold down the Shift key while scrolling and hover over the left (right) half to change the values of the x-axis min (max).  Hold the Ctrl key while scrolling to change values by a smaller increment.

You can also click the Zoom Out Completely button  to set the x-axis and y-axis ranges to the bounds of the data.  Set the Auto Range New Data button to  to automatically reset the x-axis and y-axis ranges to the bounds of the data each time new data is displayed.

File Menu

Export Window
The Histogram window can be saved to file in the following formats: bmp, jpg, png, and tif.  The size of the exported image is proportional to the size of the Histogram window.

Note: Exported Histogram windows are saved in the "Optotherm\Thermalyze\Export" folder unless you specify a different folder.
Print
Print the Histogram window.

Note: You must have a printer connected to your computer.
Print with Preview
Select this menu item to open the Print Preview dialog before printing.

Toolbar

Region Index
Select the index of the Region to display.
Update Frequency
Select the frequency to update the data in the graph.  Select max to update the graph each time new data is available.
 Freeze Updates
Press this button to temporarily freeze graph updates.
 Select
Select this button when finished zooming or panning to allow placement of the vertical cursor on the graph.
 Zoom In
Select this button to zoom into the graph.  Click and drag on the graph to select a rectangular area to zoom into.
 Zoom Out
Click this button to zoom out of the graph one level.  Continue clicking this button to zoom out additional level.
 Zoom Out Completely
Click this button to set the x-axis and y-axis ranges to the bounds of the data.
 Pan
Select this button and then click and drag on the graph to pan.
 Auto Range New Data
Press this button to automatically reset the x-axis and y-axis ranges to the bounds of the data each time new data is displayed.

Cursor Info

Temperature
This field displays the center value of the histogram x-axis temperature interval.
Position
This field displays the number of pixels in the selected Region whose temperature lies within the temperature interval whose center value is displayed on the x-axis.

Strip Chart

Description

The Strip Chart plots region temperature statistics that are displayed in the Region Data Grid.  Statistical data can be added to the Strip Chart while capturing images or when playing an image sequence.  Statistics from up to four Regions can be plotted simultaneously. To open the Strip Chart window (see Figure 3), select the Strip Chart item from the Graphs menu or press the  button on the Shortcuts toolbar.

Figure 3: Strip Chart window

Create a Strip Chart

  1. Create one or more Regions or open a region file.

  2. On the top toolbar, select the rate at which to plot the Region statistics.

  3. Below the Strip Chart, select the Region indexes and the Statistics to plot.

  4. Capture images or play an image sequence.

  5. Press the Plot Data button  to plot the statistics from the selected Regions.

Adjust the X and Y Axes

Hover over the top half of the chart and use the mouse scroll wheel to change the y-axis max value.  Hover over the bottom half to change the y-axis min value.  Hold down the Shift key while scrolling and hover over the left (right) half to change the values of the x-axis min (max).  Hold the Ctrl key while scrolling to change values by a smaller increment.

You can also click the Zoom Out Completely button  to set the x-axis and y-axis ranges to the bounds of the data.  Set the Auto Range New Data button to  to automatically reset the x-axis and y-axis ranges to the bounds of the data each time new data is displayed.

File Menu

Open Chart
Select the binary Strip Chart file (.ocht) to open.
Save Chart
Strip Chart files are saved in binary format with a ".ocht" extension.

Note: When saving a strip chart file, the file name that you provide is appended with ".ocht" and saved in the "Optotherm\Thermalyze\Strip Charts" folder unless you specify a different folder.

Note: The file name of the most recently opened or saved chart file is displayed at the bottom of the Strip Chart window.
Export Window
The Strip Chart window can be saved to file in the following formats: bmp, jpg, png, and tif.  The size of the exported image is proportional to the size of the Strip Chart window.

Note: Exported Strip Chart windows are saved in the "Optotherm\Thermalyze\Export" folder unless you specify a different folder.
Export Temperatures
The Region statistics values in a Strip Chart can be saved to file in ASCII text format (.txt) or binary format (.imb) for import into a spreadsheet program or your own custom application.

In ASCII text format, each x-axis time increment is saved followed by the statistic for each Region.  Items are separated by tab characters.  X-axis time increments are saved in units of seconds and statistics values are saved in units of degrees Celsius (for example, 53.48).  A newline character (carriage return/line feed) separates each time increment/statistics group.

In binary format, all data is saved sequentially with no separators.  Both x-axis time and statistics are saved as four-byte floating-point values in little endian format.
Print
Print the Strip Chart window.

Note: You must have a printer connected to your computer.
Print with Preview
Select this menu item to open the Print Preview dialog before printing.

Strip Chart Controls

 Plot Data
Press this button to enable data plotting while capturing images or playing an image sequence.

Tip: The cursors are hidden while this button is pressed.
Plot Rate
Select the rate at which data will be plotted.

Note: The Strip Chart can hold up to 100,000 data points for each of the four plots.  For example, when capturing images at 60 images/sec, the Strip Chart can hold over 27 minutes of data.  When capturing at 1/sec, the Strip Chart can hold over 27 hours of data.
Plotted Points
This field displays the number of x-axis time intervals in the plot.

Note: The total number of points in the plot actually is 4 times this value because the statistics for each of the 4 Regions are plotted at each x-axis time interval.
 Clear All Data
Click this button to clear all of the data from the Strip Chart.
Update Frequency
Select the frequency to update the data in the chart.  Select max to update the graph each time new data is available.
 Select
Select this button when finished zooming or panning to allow placement of the vertical cursor on the chart.
 Zoom In
Select this button to zoom into the chart.  Click and drag on the chart to select a rectangular area to zoom into.
 Zoom Out
Click this button to zoom out of the chart one level.  Continue clicking this button to zoom out additional level.
 Zoom Out Completely
Click this button to set the x-axis and y-axis ranges to the bounds of the data.
 Pan
Select this button and then click and drag on the chart to pan.
 Auto Range New Data
Press this button to automatically reset the x-axis and y-axis ranges to the bounds of the data each time new data is displayed.
 Crop Left
Position the vertical cursor on the first data point that you want to keep and then press this button to remove all data to the left of the cursor.
 Crop Right
Position the vertical cursor on the last data point that you want to keep and then press this button to remove all data to the right of the cursor.

Data to Plot

Show
Check this box to display a plot.
Region
Select the index of the Region to plot.
Statistic
Select the Region’s Max, Min, or Mean statistic to plot.

Cursor Temp

While plotting data, the vertical cursor is hidden.  While not plotting, click the chart to position the vertical cursor.

Time
While plotting data, this field displays the x-axis time of the most recently plotted point.  When not plotting, this field displays the x-axis time position of the vertical cursor.
Cursor TempCursor Temp
While plotting data, these fields display the temperature statistics of the most recent plotted points.  When not plotting, these fields display the temperature statistics of each plot at the cursor x-axis position.