When Image Processing Is Used?
Many users build their In-Sight jobs without the Image tool, and use the tool only if their jobs fail to produce the desired results. Image functions can be used for any of the following conditions:
- The acquired image is in color. The In-Sight tools operate only on greyscale images, and although each tool is designed to convert images from color to greyscale automatically, it can be more efficient to perform the conversion only once using an Image function and to reference subsequent tools to the converted image.
- The acquired image displays little contrast between the object and its background.
- The acquired image contains distracting features that minimize the visual impact of the object.
- The acquired image is out of focus, and adjustments to the vision system lens are needed.
- An enlarged, reduced, unbent or unrotated version of the acquired image is required by another In-Sight tool.
- A black-and-white version of the acquired image is required by another In-Sight tool.
Image functions can perform a variety of image-processing operations. Most of the functions target a specific operation; three are designed for multipurpose use. The following table lists common operations and the applicable Image functions.
Operation |
Description |
Applicable Image Function |
---|---|---|
Brightness/contrast |
"Clips" (or "scales up" or "scales down") the greyscale value in each pixel to user-specified minimum and maximum values to modify brightness and contrast. |
|
Color adjustment | Converts or corrects the color of the input image; available only for color In-Sight vision systems or color-enabled emulators. | |
Expansion/contraction | Expands or contracts features in the input image or ROI. | |
Filling | Fills pixels with white or black values so that they resemble adjacent pixels. | |
Filtering | Blocks undesirable or unwanted data, while passing only desirable data. | |
Image differences | Compares the input image with a template, another image or a shape to determine differences between the two. | |
Inverse | Creates a "negative" of the image. | |
Lens adjustment | Measures the lens focus so that it can be adjusted through an iterative process. | ComputeImageSharpness |
Scaling (size) | Presents an enlarged or reduced version of the input image in the job view. | |
Sharpening | Discovers edges (that is, areas in an image where pixel greyscale values change sharply) based on orientation (vertical, horizontal); or enhances edges by comparing a "smoothed" version of the image with the original. | |
Smoothing | Averages the greyscale values in a set of adjacent pixels ("neighbors") in the input image to diminish the effect of rapidly changing greyscale values. | |
Thresholding | Produces a black-and-white version of the input image or ROI based on a user-set threshold. |