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OCR Reading. Class Summary. Description Overview of how to use the OCR softsensor Advanced Settings Class Level Intermediate Prerequisites Basic FrameWork Training. OCR SoftSensors. Optical Character Recognition (OCR)
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Class Summary • Description • Overview of how to use the OCR softsensor • Advanced Settings • Class Level • Intermediate • Prerequisites • Basic FrameWork Training
OCR SoftSensors • Optical Character Recognition (OCR) • Recognizing and reading characters by comparing to list of previously trained ones. Reading any code containing these characters • Optical Character Verification (OCV) • Matching a particular pattern of predetermined characters. Verifying a specific string of characters
OCR SoftSensors • Sample application industries • Pharmaceutical • Automotive • Electronics/Semiconductors • Packaging • General manufacturing
OCR SoftSensors • Variety of special threshold options • Computed, linear and non-linear • Train your own characters • Ability to read dot matrix, segmented and stroke (e.g. Japanese) characters • Capability of handling rotation and reading curved text • Control of spacing and character size
OCR SoftSensors: For Best Results • Characters must be able to be extracted by thresholding • Characters must be repeatable from one image to the next • Avoid images with textured or printed backgrounds • OCR “friendly” fonts • OCR A, OCR B, Semi • Undecorated, non-serif fonts • Character height between 20 and 30 pixels
Advanced OCR Features. • Thresholding changes: • Dominant Color • AutoBimodal ~ Automatically calculates a single threshold value to use based on the entire histogram. Reduces the effects of noise and specular reflections. • Adaptive ~ Calculates a specific threshold value for different areas of the image depending on the contrast found in those areas. Makes the overall threshold more robust when lighting and contrast are not uniform. 7
Advanced OCR Features. Dialog boxes changed to make set-up easier. 8
Advanced OCR Features. New font list with images. 9
Advanced OCR Features. New Character Info with images. 10
Advanced OCR Features. Orphan Removal ~ Disregard pixels that are not part of the character but are of the same intensity value as the character. 11
Advanced OCR Features. Fill Characters ~ will fill in the holes in a character which helps with the matching process. 12
Advanced OCR Features. Minimum edge width ~ This parameter can be used to filter out noise by requiring a minimum number of character pixels in order to start forming a character box. 13
Advanced OCR Features. Advanced Maximum Character Width ~ When this parameter is used, the system will start at the maximum character width location and search backwards 20% of the maximum character width looking for the vertical line which has the fewest character pixels. 14
Advanced OCR Features. Aspect Ratio Dependence ~ When enabled the tolerated variance is user definable. When disabled, objects must be within ±200% of the object in the font list or no comparison is made. 15
Advanced OCR Features. Resolution selection. Features matched per character: 200 800 1600 LOW MEDIUM HIGH 16
Rotated, Skewed and Italicized Characters • Use the Parallelogram OCR Softsensor • Take care drawing the sensor, it is sensitive to angles. 17
Conclusion • Characters must be repeatable from one image to the next • Avoid images with textured or printed backgrounds • OCR “friendly” fonts • OCR A, OCR B, Semi • Undecorated, non-serif fonts • Character height between 20 and 30 pixels • Use OCV whenever possible to eliminate misreads