Column Profile Plot


A Column Profile plots the pixel values along a line parallel to the image columns. The column(s) to be plotted are located using the Image Cursor. This type of plot shows changes in image luminance, or pixel value, in the vertical direction. Alternatively, you can create a column profile plot using the Line Profile tool to draw precisely along a single column. To plot in the perpendicular direction, use a Row Profile Plot.

Types of Column Profile Plots

This command plots the following types of profiles:

If the Image Window has 2 or more images in an Image Set, Mira can make the above types of plots for the entire image set or for only the top image; this is controlled by the state of the Graph Image Set mode.

The Window Caption describes the type of plot that is displayed:

Procedures

Making a column profile plot involves two steps:

  1. Adjusting the image cursor to cover the desired pixels, and

  2. Clicking the plotting button or executing the menu command to create the plot.

Plotting a Single Column

  1. Set the command mode to Cursor Mode.

  2. Click the mouse on the image to position the Image Cursor.

  3. Adjust the corners or edges of the Image Cursor until it defines the region you wish to average. Combine moving and sizing operations to get the image cursor where you want it.

  4. Execute the Plot > Column command in the menu or click the button to make the plot.

Plotting an Average Column

Mira can combine the neighboring columns and plot the result as a single line of data. Mira provides different options for combining the adjacent lines to create the plot; see Plot Averaging Mode.

  1. Set the command mode to Cursor Mode. If the image cursor is a rectangle, it outlines the region to be averaged into a single column. If it is a crosshair, the averaged region is the number of columns spanned by the crosshair. In both cases, the same number of columns will be averaged.

  2. Combine moving and sizing operations to get the image cursor where you want it. Click the mouse on the image to position the cursor and adjust the corners or edges until it defines the range of columns to average.

  3. Select the column combining method by choosing an option in the Combine Mode submenu of the buttons' drop menu or use the image Plot menu or Image Context Menu. The name in the menu adjusts to the selected method.

  4. Execute the particular [Average Column] command in the menu. The plot title depends on the currently selected Averaging Mode. Also see Plotting an Averaged Line.

Plotting a Range of Columns

This command plots all rows inside the image cursor box to view them simultaneously or as an animation.

  1. Set the command mode to Cursor Mode. If the image cursor is a rectangle, it outlines the region of columns to be plotted. If it is a crosshair, the span of the crosshair defines the number of columns to be plotted. In both cases, the same number of columns will be plotted.

  2. Combine moving and sizing operations to get the image cursor where you want it. Click the mouse on the image to position the cursor and adjust the corners or edges until it defines the range of columns to plot.

  3. In the plotting menu set the Plot Series Mode to Overplot and then use the Range of Rows command. You can later change the Plot Series Mode from the Plot Window using its Context Menu.

Changing the Plot Appearance

After you have made the plot, the attributes can be changed using the Plot Attributes dialog. This includes properties such as the minimum and maximum extent of the axes, the tick marks, axis labels, fonts, colors, and more.

Related Topics

Plotting Commands, Row Profile Plot, Line Profile Plot, Plot Animation Toolbar, Plot Coordinate Systems, Plot Attributes, Copy and Paste Commands for Plots, Plotting an Averaged Line