Settings

• Output Selector - Selects one from this list to be the pixel value of the output image:

• Dx - Gradient along the x-axis.

• Dy - Gradient along the y-axis.

• Magnitude (Default) - Magnitude of the gradient.

• Angle - Angle of the gradient.

• Qualified Angle - Is the Angle divided by 2 (or right-shifted by 1). For pixel points whose Magnitude exceeds the Magnitude Qualification (shown in the datum view), the highest bit of the Qualified Angle is set to 1, resulting in a value between 128 and 255. In other words, for the qualified points, the Qualified Angle values are between 128 and 255; while for the non-qualified points, the Qualified Angle values are half of the original Angle value and, therefore, are between 0 and 127.

• Absolute Gradient-x - Absolute value of the gradient along the x-axis.

• Absolute Gradient-y - Absolute value of the gradient along the y-axis.

• 3-Bit Mag & 5-Bit Ang - Is a combination of 3-bit magnitude and
  5-bit angle. The placement of these bits are shown in Figure 13-12 and Figure 13-13.

• 4-Bit GradX & 4-Bit GradY - Is a combination of 4-bit Grad-X and
  4-bit Grad-Y. The placement of these bits are shown in and Figure 13-13.

• Sum of Absolute Gradients - Absolute value of the gradient along the x-axis plus the absolute value of the gradient along the y-axis.

• Sobel Mag Shift Down (# bits) - The amount of shift operation on the gradients Dx and Dy. Right-shift is a type of high-pass filter to the gradients. This is applied to the gradient along the x-axis and y-axis individually:

• None

• Shift 1 bit down

• Shift 2 bits down

• Shift 3 bits down

• Magnitude Qualification - Used as a threshold to qualify a point for the calculation of the Qualified Angle. It also calculates the following statistics:

• Sum of Qualified Gray Values - Sum of the gray values of those pixels whose gradient magnitude exceeds the Magnitude Qualification.

• Cnt of Qualified Gray Values - Count of those pixels whose gradient magnitude exceeds the Magnitude Qualification.

• Output Qualification - Threshold used for calculating the following output statistics:

• Sum of Qualified Output - Sum of the sobel outputs values that exceed this Output Qualification.

• Cnt of Qualified Output - Count of those pixel points where the sobel output values exceed this Output Qualification.

Note: These statistics are calculated only when Calculate Qualified Output Stat is enabled (checked).

• Size of Neighborhood - Provides the following selections:

• 3x3 (default)

• 5x5

• 7x7

• Calculate Qualified Output Stat - When enabled (checked), Output Qualification is a threshold to calculate the statistics Sum of Gray Values and Cnt of Gray Values in the Output Image.

• Stop if Pollution Exists - If the neighborhood operation would involve padded (unknown) pixels, the sobel processing will stop if this setting is enabled.

• Highlite Polluted Pixels - If any pollution exists along the border of the ROI, the polluted pixels, where the sobel outputs are calculated with padded (unknown) pixels, will be highlighted red when enabled.