Filter

The row offset, in image coordinates.

The column offset, in image coordinates.

The angle of orientation, in the image coordinate system.

The x-offset of the origin, in fixture coordinates.

The y-offset of the origin, in fixture coordinates.

The dimension along the region's x-axis.

The dimension along the region's y-axis.

The orientation, in fixture coordinates.

Specifies a black-and-white ("binary") threshold operation that compares each input pixel with the threshold level to determine whether the output pixel is white or black. Input pixel values equal to or above the Threshold parameter value are white; values below the threshold are black.

Specifies a "bottom hat" filtering operation that filters out everything except dark features that are smaller than the size of the kernel neighborhood. The result is an output image that displays these dark features as bright pixels on an otherwise dark background.

Specifies a "clipping" operation that eliminates the extreme ends of the greyscale spectrum so that the features in the output image are more uniform. This operation compares the greyscale value of each input pixel to the Min and Max parameter values:

• If the input pixel value is equal to or exceeds the minimum or the maximum, the output pixel is assigned ("clipped" to) the minimum or maximum value, respectively.
• If the input pixel value is within the minimum and maximum, the output pixel is assigned the value of the input pixel.

Specifies a "closing" operation that performs a dilation followed by an erosion to filter out dark features that are smaller than the size of the kernel neighborhood. Closing an image reduces or completely removes dark areas of the image.

Specifies a "dilation" operation that enhances the bright features of the image while suppressing the darker features. The result is an output image with larger areas of bright pixels. Useful for removing dark specks.

Specifies an operation that displays the difference between a dilation and an erosion of the input image. The result is an output image where edges are represented by bright pixels. Though similar to Gradient Full, this operation is more complex (and slower), allowing diagonally oriented edges to be represented.

Specifies a histogram equalization operation that extracts the histogram of the input image and spreads out the most frequent greyscale values to create a more even distribution. The result is an output image with increased contrast. This type of filter is useful in environments where the lighting can vary slightly from one image to the next, or when some aspects of the object being inspected can slightly vary.

Specifies an "erosion" operation that reduces the bright features of the image. The result is an output image with larger areas of dark pixels. Useful for removing light specks, noisy pixels and/or small defects.

Specifies a "pixel-filling" operation, where dark pixels surrounded by light pixels are converted to light pixels. The result is an output image where dark holes are filled.

Specifies a "pixel-filling" operation, where light pixels surrounded by dark pixels are converted to dark pixels. The result is an output image where light holes are filled.

Specifies a "vertical and horizontal gradient" operation that results in an output image where both vertically and horizontally oriented edges are represented by bright pixels. Though similar to Edge Magnitude, this operation is simpler (and faster) and does not represent diagonally oriented edges.

Specifies a "horizontal gradient" operation that results in an output image where horizontally oriented edges are represented by bright pixels.

Specifies a "vertical gradient" operation that results in an output image where vertically oriented edges are represented by bright pixels.

Specifies the greyscale value of each output pixel as the difference between the greyscale value of each input pixel and the threshold level (for example, if the input pixel value is 100 and the threshold is 25, then the output pixel value will be 75), which is determined by the Threshold parameter.

Specifies a "high-pass" operation that results in an output image where edges are enhanced relative to areas with more consistent greyscale gradient. This type of filter is useful in accentuating fine features.

Specifies an inversion of pixel values based on the 256-step greyscale that results in an output image that is a "negative" of the input image (for example, inverting an input pixel value of 10 results in an output pixel value of 245).

Specifies an operation that computes the median pixel value of the pixel values in the kernel neighborhood, then uses this result as the output image pixel value.

Specifies a means to subtract the background from an image; this operation subtracts the local median of the input image from the input image, shifts the result right by one, and then adds 128 to produce the output pixel value.

Specifies a "low-pass" operation that results in an output image in which edges are smoothed or blurred.

Specifies an operation that uses the maximum of Top Hat and Bottom Hat operations.

Specifies an "opening" operation that performs an erosion followed by a dilation to filter out bright features that are smaller than the size of the kernel neighborhood. The result is an output image with slightly decreased overall brightness; removing small amounts of bright pixels and enhancing the remaining bright features.

Specifies an inversion of pixel values based on a logarithmic scaleOutput pixel value = 100 * log (255) - 100 * log (input pixel value). The result is an output image that reveals the density of objects and features in the input image by measuring the amount of light that passes through them. Denser objects and features are represented by lighter pixels in the output image.

Specifies a "sharpness" operation that is used to enhance edges. The operation evaluates the contrast between adjacent pixels, and increases the contrast when the contrast is high. A large contrast difference between adjacent pixels usually represents an edge; however, this operation should not be used to locate edges. The effects that the operation will have are dependent upon the image content and the resolution.

• The Smoothness parameter is used to identify the edges by creating a Gaussian kernel.
• The Gain parameter dictates the strength of the sharpening, instructing the filter to ignore a certain amount of difference between pixels when sharpening so that lightly textured areas will not be over-sharpened.

Specifies a greyscale stretching operation that linearly "scales up" or "stretches" the greyscale values (based on the Min and Max parameter settings) in the input image to the full 256-step greyscale, resulting in an output image with increased contrast. If the input pixel value is equal to or exceeds the minimum or maximum, the output pixel is assigned to 0 or 255, respectively. For input pixel values within the minimum and maximum, they will be linearly stretched to the 0 to 255 range. For example, if the Min is 50 and the Max is 180, the operation subtracts 50 from each pixel's intensity, making the range 0 to 130. Then each pixel intensity is multiplied by 255/130, creating the range of 0 to 255.

Specifies a black-and-white ("binary") threshold operation that compares each input pixel with two threshold values (Min and Max) to determine whether the output pixel is background or foreground. If the input pixel value is within the minimum and maximum, the output pixel retains its value, otherwise, the output pixel is set to the background level.

Specifies the "top hat" filtering operation, which filters out everything except bright features that are smaller than the size of the kernel neighborhood. The result is an output image that displays these bright features as bright pixels on an otherwise dark background.