EP0437968A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Video densitometer
Assignee: Research Development Foundation
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Filing: 1990-12-21
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Granted: —
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Expires: 2010-12-21
Abstract
Abstract The measurement of integrated densities of irregularly shaped areas of a subject specimen (52) is accomplished by using a video camera (54) to derive an analog video image signal representative of the optical intensity of light associated with the specimen. A modified low cost high speed video digitizer (58) converts the video image signal into a digital format which an interactive computer program converts into digital optical density values that are used to determine the net integrated density of each irregularly shaped area within the specimen.
Inventors
- 👤 Daniel M. Ziegler
- 👤 Lawrence L. Poulsen
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 03:25
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/59; G01N21/5907; G01N21/5911; G01N27/00; G01N27/26; G01N27/416; G01N27/447; G01N27/44704; G01N27/44717; G01N27/44721; G06; G06T; G06T7/00; G06T7/90; G01N2021/1765; G01N2021/177; G01N2021/5915; G01N2021/5919; G01N30/00; G01N30/90; G01N30/95; G06T2207/00; G06T2207/10; G06T2207/10016; G06T2207/30; G06T2207/30004
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
139 words
A method for determining an integrated density of irregularly shaped light absorbing areas of a subject specimen, comprising the steps of: deriving an analog video image signal representative of light associated with the optical intensity of the specimen; calibrating the video image dark intensity to a black level; calibrating the video image bright intensity to a white level; converting the calibrated analog video image signal into a set of digital values; converting the digital values representing intensity to digital values representing density; displaying a digital format image of the specimen based upon the digital density values; selecting an area of the displayed digital format image for calculation of spot density; calculating a background density value for the selected area of the digital format image; and calculating a spot density value for the selected area of the digital format image.
Claim 2
Dependent Claim
58 words
The method of claim 1, wherein the step of calibrating the video image dark intensity to a black level comprises: repetitively counting the number of digital density values equal to zero while adjusting an analog voltage means for changing the video image dark intensity threshold bias until the preferred number of digital density values is equal to zero.
Claim 3
Dependent Claim
64 words
The method of claim 1, wherein the step of calibrating the video image bright intensity to a white level comprises: repetitively counting the number of digital density values equal to a maximum digital value while adjusting an analog voltage means for changing the video image bright intensity threshold bias until the preferred number of digital density values is equal to the maximum digital value.
Claim 4
Dependent Claim
32 words
The method of claim 1, wherein the step of converting the intensity values to density values comprises: calculating a reciprocal value of the intensity; and calculating the log₁₀ of the reciprocal value.
Claim 5
Dependent Claim
65 words
The method of claim 1, wherein the step of calculating a background density comprises: summing the digital density values located on the left and right vertical edges of the selected area, dividing the sum of the left and right vertical edge densities by the number of the digital density values summed, and multiplying by the number of digital density values contained within the selected area.
Claim 6
Dependent Claim
29 words
The method of claim 1, wherein the step of calculating a spot density comprises: summing the digital density values within the selected area and subtracting the background density value.
Claim 7
Dependent Claim
97 words
The method of claim 1, wherein the step of selecting an area for calculating of spot density comprises the steps of: selecting a vertical lane of spots bounded by a first and second horizontal coordinate within the displaying digital format image; calculating a plurality of lane density values, the lane density values each being representative of the sum of digital density values in a given horizontal line of density within the lane; displaying the lane density values; and selecting an upper and lower vertical coordinate for the selected vertical lane based on the displayed lane density values.
Claim 8
Dependent Claim
75 words
The method of Claim 7, wherein the step of selecting an upper and lower vertical coordinate for the selected vertical lane comprises the steps of: selecting an inception and termination of a lane density peak from the displayed lane density values; and calculating the lower and upper vertical coordinates from the selected inception and termination of the lane density peak, the lower and upper vertical coordinates defining a lane area for calculation of spot density.
Claim 9
Independent Claim
145 words
A method for determining an integrated density of irregularly shaped light absorbing areas of a subject specimen, comprising the steps of: deriving an analog video image signal representative of the optical intensity of light associated with the specimen; calibrating the video image dark intensity to a black level; calibrating the video image bright intensity to a white level; converting the calibrated analog video image signal into a set of digital values; converting the digital values representing intensity to digital values representing density; displaying a digital format image of the specimen based upon the digital density values; selecting an area of the displayed digital format image for calculation of spot density; calculating a background density value for the selected area of the digital format image; calculating a spot density value for the selected area of the digital format image; and displaying the calculated spot density value.
Claim 10
Independent Claim
160 words
A method for determining an integrated density of irregularly shaped light absorbing areas of a subject specimen, comprising the steps of: deriving an analog video image signal representative of the optical intensity of light associated with the specimen; calibrating the video image dark intensity to a black level; calibrating the video image bright intensity to a white level; converting the calibrated analog video image signal into a set of digital values; converting the digital values representing intensity to digital values representing density; displaying a digital format image of the specimen based upon the digital density values; selecting a plurality of areas of the displayed digital format image for calculation of a plurality of spot densities; calculating a plurality of background density values each associated with a selected area of the digital format image; calculating a plurality of spot density values each associated with a selected area of the digital format image; and displaying each of the calculated spot density values.
Claim 11
Independent Claim
163 words
A method for determining an integrated density of irregularly shaped light absorbing areas of a subject specimen, comprising the steps of: deriving an analog video image signal representative of the optical intensity of light associated with the specimen; calibrating the video image dark intensity to a black level; calibrating the video image bright intensity to a white level; converting the calibrated analog video image signal into a set of digital values; converting the digital values representing intensity to digital values representing density; displaying a digital format image of the specimen based upon the digital density values; selecting one or more areas of the displayed digital format image for calculation of one or more spot densities; calculating one or more background density values each associated with a selected area of the digital format image; calculating one or more spot density values each associated with a selected area of the digital format image; and displaying each of the one or more calculated spot density values.
Claim 12
Independent Claim
274 words
A method for determining an integrated density of irregularly shaped light absorbing areas of a subject specimen, comprising the steps of: deriving an analog video image signal with a video camera representative of the optical intensity of light associated with the specimen; calibrating the video image dark intensity to a black level by repetitively counting the number of digital density values equal to zero while adjusting an analog voltage means for changing the video image dark intensity threshold bias until the preferred number of digital density values is equal to zero; calibrating the video image bright intensity to a white level by repetitively counting the number of digital density values equal to a maximum digital value while adjusting an analog voltage means for changing the video image high intensity threshold bias until the preferred number of digital density values is equal to the maximum digital value; converting the calibrated analog video image signal into a set of digital values by using a high speed analog-to-digital converter; converting the digital values representing intensity to digital values representing density by calculating a reciprocal value of the intensity and calculating the log₁₀ of the reciprocal value; displaying a digital format image of the specimen based upon the digital density values; selecting one or more areas of the displayed digital format image for calculation of one or more spot densities; calculating one or more background density values each associated with a selected area of the digital format image; calculating one or more spot density values each associated with a selected area of the digital format image; and displaying each of the one or more calculated spot density values.
Claim 13
Independent Claim
158 words
An apparatus for determining an integrated density of irregularly shaped light absorbing areas of a subject specimen, comprising the steps of: means for deriving an analog video image signal representative of light associated with the optical intensity of the specimen; means for calibrating the video image dark intensity to a black level; means for calibrating the video image bright intensity to a white level; means for converting the calibrated analog video image signal into a set of digital values; means for converting the digital values representing intensity to digital values representing density; means for displaying a digital format image of the specimen based upon the digital density values; means for selecting an area of the displayed digital format image for calculation of the spot density; means for calculating a background density value for the selected area of the digital format image; and means for calculating a spot density value for the selected area of the digital format image.
Claim 14
Dependent Claim
60 words
The apparatus of claim 13, wherein the means for calibrating the video image dark intensity to a black level comprises: means for repetitively counting the number of digital density values equal to zero while adjusting an analog voltage means for changing the video image dark intensity threshold bias until the preferred number of digital density values is equal to zero.
Claim 15
Dependent Claim
36 words
The apparatus of claim 13 wherein the means for converting the intensity values to density values comprises: means for calculating a reciprocal value of the intensity; and means for calculating the log₁₀ of the reciprocal value.
Claim 16
Dependent Claim
67 words
The apparatus of claim 13, wherein the means for calculating a background density comprises: means for summing the digital density values located on the left and right vertical edges of the selected area, dividing the sum of the left and right vertical edge densities by the number of the digital density values summed, and multiplying by the number of digital density values contained within the selected area.
Claim 17
Dependent Claim
102 words
The apparatus of claim 13, wherein the means for selecting an area for calculation of spot density comprises: means for selecting a vertical lane of spots bounded by a first and second horizontal coordinate within the displayed digital format image; means for calculating a plurality of lane density values, the lane density values each being representative of the sum of digital density values in a given horizontal line of density within the lane; means for displaying the lane density values; and means for selecting an upper and lower vertical coordinate for the selected vertical lane based on the displayed lane density values.
Claim 18
Dependent Claim
102 words
The apparatus of claim 13, wherein the means for selecting an area for calculation of spot density comprises: means for selecting a horizontal row of spots bounded by a first and second vertical coordinate within the displayed digital format image; means for calculating a plurality of row density values, the row density values each being representative of the sum of digital density values in a given vertical line of density within the row; means for displaying the row density values; and means for selecting a left and right horizontal coordinate for the selected horizontal row based on the displayed row density values.
Claim 19
Independent Claim
162 words
An apparatus for determining an integrated density of irregularly shaped light absorbing areas of a subject specimen, comprising: means for deriving an analog video image signal representative of the optical intensity of light associated with the specimen; means for calibrating the video image dark intensity to a black level; means for calibrating the video image bright intensity to a white level; means for converting the calibrated analog video image signal into a set of digital values; means for converting the digital values representing intensity to digital values representing density; means for displaying a digital format image of the specimen based upon the digital density values; means for selecting an area of the displayed digital format image for calculation of spot density; means for calculating a background density value for the selected area of the digital format image; means for calculating a spot density value for the selected area of the digital format image; and means for displaying the calculated spot density value.
Claim 20
Independent Claim
177 words
An apparatus for determining an integrated density of irregularly shaped light absorbing areas of a subject specimen, comprising: means for deriving an analog video image signal representative of the optical intensity of light associated with the specimen; means for calibrating the video image dark intensity to a black level; means for calibrating the video image bright intensity to a white level; means for converting the calibrated analog video image signal into a set of digital values; means for converting the digital values representing intensity to digital values representing density; means for displaying a digital format image of the specimen based upon the digital density values; means for selecting a plurality of areas of the displayed digital format image for calculation of a plurality of spot densities; means for calculating a plurality of background density values each associated with a selected area of the digital format image; means for calculating a plurality of spot density values each associated with a selected area of the digital format image; and means for displaying each of the calculated spot density values.
Claim 21
Independent Claim
180 words
An apparatus for determining an integrated density of irregularly shaped light absorbing areas of a subject specimen, comprising: means for deriving an analog video image signal representative of the optical intensity of light associated with the specimen; means for calibrating the video image dark intensity to a black level; means for calibrating the video image bright intensity to a white level; means for converting the calibrated analog video image signal into a set of digital values; means for converting the digital values representing intensity to digital values representing density; means for displaying a digital format image of the specimen based upon the digital density values; means for selecting one or more areas of the displayed digital format image for calculation of one or more spot densities; means for calculating one or more background density values each associated with a selected area of the digital format image; means for calculating one or more spot density values each associated with a selected area of the digital format image; and means for displaying each of the one or more calculated spot density values.
Claim 22
Independent Claim
291 words
An apparatus for determining an integrated density of irregularly shaped light absorbing areas of a subject specimen, comprising: means for deriving an analog video image signal with a video camera representative of the optical intensity of light associated with the specimen; means for calibrating the video image dark intensity to a black level by repetitively counting the number of digital density values equal to zero while adjusting an analog voltage means for changing the video image dark intensity threshold bias until the preferred number of digital density values is equal to zero; means for calibrating the video image bright intensity to a white level by repetitively counting the number of digital density values equal to a maximum digital value while adjusting an analog voltage means for changing the video image high intensity threshold bias until the preferred number of digital density values is equal to the maximum digital value; means for converting the calibrated analog video image signal into a set of digital values by using a high speed analog-to-digital converter; means for converting the digital values representing intensity to digital values representing density by calculating a reciprocal value of the intensity and calculating the log₁₀ of the reciprocal value; means for displaying a digital format image of the specimen based upon the digital density values; means for selecting one or more areas of the displayed digital format image for calculation of one or more spot densities; means for calculating one or more background density values each associated with a selected area of the digital format image; means for calculating one or more spot density values each associated with a selected area of the digital format image; and means for displaying each of the one or more calculated spot density values.
References Cited (Backward Citations)
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