Back to results
US 6,674,896 B1Granted
Device for applying accurate color thresholds in real time
AssigneeChromaVision Medical Systems, Inc.
InventorJose De La Torre-Bueno
Life of this patent
Estimating the term…
Abstract
A keyed color generator for use in a machine vision system may include three color channels with a subtractor in each to subtract a corresponding component color of a background on which the object under inspection is being observed. This subtraction operation produces adjusted red (R), green (G), and blue (B) values. The R and B values may be divided by the adjusted G value to produce R/G and B/G color ratios. These color ratios and the adjusted G value may be compared to associated upper and lower threshold values corresponding to a keyed color. If all of the calculated values fall within the associated ranges, the generator outputs a signal indicative of the keyed color.
Claims9
An apparatus comprising:
- a plurality of color channels, each color channel corresponding to a different component color value, and comprising a subtractor to subtract a component color value of a background color from a component value of a pixel color to produce an adjusted color value;
- a divider to divide at least one of said component color values by another of said component color values to produce a color ratio;
- a keyed color indicator to generate a signal in response to each of the adjusted color value and the color ratio falling within an associated range of values corresponding to a keyed color;
- a first subtractor in a first color channel to subtract a first color component of a background color from a first color component of an input pixel color to produce a first adjusted value;
- a second subtractor in a second color channel to subtract a second color component of the background color from a second color component of the input pixel color to produce a second adjusted value;
- a divider to divide the first adjusted value by the second adjusted value to produce a first color ratio;
- a first comparison circuit to determine if the first color ratio falls in a first range of values;
- a second comparison circuit to determine if the second adjusted color falls in a second range of values;
- and
- a logic circuit to output a signal indicative of a keyed color in response to the first color ratio falling within the first range and the second adjusted color falling within the second range.
7 more elements
A system comprising:
- a camera to image an object;
- a digitizer connected to the camera to digitize the image into a frame comprising a plurality of pixels, each pixel having a color value;
- and
- a keyed color generator comprising:
- a plurality of color channels, each color channel corresponding to a different component color value, and comprising a subtractor to subtract a component color value of a background color from a component value of a pixel color to produce an adjusted color value;
- a divider to divide at least one of said component color values by another of said component color values to produce a color ratio;
- a keyed color indicator to generate a signal in response to each of the adjusted color value and the color ratio falling within an associated predetermined range of values;
- a first subtractor in a first color channel to subtract a first color component of a background color from a first color component of an input pixel color to produce a first adjusted value;
- a second subtractor in a second color channel to subtract a second color component of the background color from a second color component of the input pixel color to produce a second adjusted value;
- a third subtractor in a third color channel to subtract a third color component of the background color from a third color component of the input pixel color to produce a third adjusted value;
- a first divider to divide the first adjusted value by the second adjusted value to produce a first color ratio;
- a second divider to divide the third adjusted value by the second adjusted value to produce a second color ratio;
- a first comparison circuit to determine if the first color ratio falls in a first range of values;
- a second comparison circuit to determine if the second adjusted color falls in a second range of values;
- a third comparison circuit to determine if the second color ratio falls in a third range of values;
- and
- a logic circuit to output a signal indicative of a keyed color in response to the first color ratio falling within the first range and the second adjusted color falling within the second range and the second color ratio falling with the third range of values.
14 more elements
Dependencies are inferred from the claim text.