Blob_ (GRIP)

java.lang.Object
- net.grelf.grip.Blob_

All Implemented Interfaces:

java.io.Serializable, Blob
```
public final class Blob_
extends java.lang.Object
implements Blob, java.io.Serializable
```
Representing the shape of a contiguous set of pixels which have been detected in an image. The shape is described by a list of points defining the boundary together with a list of horizontal lines (of type Blob.BlobRow) defining the area enclosed by the boundary. This double description is to facilitate drawing and measuring the object.

This class also contains a static method for detecting a list of Blobs from a mask, such as would have been set by thresholding - see class ImThreshRGBDialogue.

See Also:

Serialized Form

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class Blob_.BlobRow

Nested Classes
Modifier and Type	Class and Description
`static class`	`Blob_.BlobRow`

Constructor Summary

Constructors
Constructor and Description
`Blob_(int x, int y)` Construct a 1-pixel blob at (x, y) - for a detected pixel with no neighbours.
`Blob_(java.util.List<java.awt.Point> aBoundary, byte[][] mask)` Construct a Blob from a boundary (list of points) and a mask.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`int`	`area()` Measure the area of the blob, as the total number of pixels in its rows.
`int[]`	`boundaryMedianLevel(Image image)` Get the median level in each channel around the boundary in the given image.
`int[]`	`brightness(Image image)` Measure the integrated detected brightness (NOT the average) in each channel
`PointFloat`	`densityCentre(Image image)` Calculate the centre of the blob with weighting from pixel densities (brightnesses).
`BlobFrame`	`display(ImFrame srcFrame, BlobMeas meas)` Display this blob magnified in a new BlobFrame.
`void`	`drawBoundary(byte[][] mask, byte value)` Draw the boundary of the blob in the mask array with the given value.
`void`	`drawBoundary(Image image, int[] levels)` Draw the boundary of the blob in the given image with the given levels.
`void`	`drawRegion(byte[][] mask, byte value)` Draw the rows of the blob in the mask array with the given value.
`void`	`drawRegion(Image image, int[] levels)` Draw the rows of the blob in the given image with the given levels.
`void`	`erase(byte[][] mask)` Erase this blob from a given mask.
`void`	`eraseToBackground(BlobMeas meas, ImFrame parentFrame)` For removing stars during comet stacking.
`Blob`	`getBackgroundDisc()` For accurate brightness measurement in BlobMenu.
`java.util.List<java.awt.Point>`	`getBoundary()`
`Bounds`	`getBounds()` Get the bounds of this Blob.
`Blob`	`getBrightnessDisc()` For accurate brightness measurement in BlobMenu.
`protected Blob`	`getDisc(int radius, int imWd, int imHt, byte value)` Get a blob describing a solid disc of given radius in the centre of a rectangle of given width and height.
`float`	`getMeasuringRingSizeFactor()` Get the factor by which the measuring circles in display () are expanded.
`java.util.List<Blob_.BlobRow>`	`getRegion()`
`java.util.List<Blob_.BlobRow>`	`getRows()` Representing the filled region, including the boundary.
`java.util.List<PointFloat>`	`getVerticalCentreLineFromBoundary()` Get a list of the centre points of all horizontal rows that comprise the blob with a simple shape.
`java.util.List<PointFloat>`	`getVerticalCentreLineFromRegion()` Get a list of the centre points of all horizontal rows that comprise the blob.
`boolean`	`hasRows()` Whether region comprises at least one row.
`boolean`	`isSaturatedInRegion(Image srcImage)` Rescan the region (rows) of this blob to determine whether it is saturated (ie, reaching maximum level in any band).
`boolean`	`isSaturatedInRegion(ImFrame srcFrame)` Rescan the region (rows) of this blob to determine whether it is saturated (ie, reaching maximum level in any band).
`LineSegment`	`longestLine()` Find the two points on the boundary which are furthest apart from each other, returning the result as a LineSegment.
`PointFloat`	`maskCentre()` Calculate the centre of the blob simply as average of detected x and y, with no weighting from pixel densities.
`BlobMeas`	`measure(Image image)` Measure brightness, density-weighted centre and area (pixel count) all on one pass.
`void`	`measureAccurately(BlobMeas meas, Image image)` Measure meanBackground, accurateBrightnesses and snRatios fields of the given BlobMeas using backgroundDisc and brightnessDisc in the given frame (which is assumed to be the parent frame of the magnified blob frame). The signal-to-noise (S/N) ratio for each channel is measured as (mean (starBrightness) - mean (backgroundBrightness)) / stdDev (backgroundBrightness) where mean (starBrightness) is the accurately measured brightness in the inner disc divided by the number of pixels in that disc.
`void`	`measureAccurately(BlobMeas meas, ImFrame parentFrame)` Measure meanBackground, accurateBrightnesses and snRatios fields of the given BlobMeas using backgroundDisc and brightnessDisc in the given frame (which is assumed to be the parent frame of the magnified blob frame). The signal-to-noise (S/N) ratio for each channel is measured as (mean (starBrightness) - mean (backgroundBrightness)) / stdDev (backgroundBrightness) where mean (starBrightness) is the accurately measured brightness in the inner disc divided by the number of pixels in that disc.
`protected void`	`nullRows()` Available for saving memory if the boundary has to be kept but we no longer need the region.
`double`	`perimeter()` Measure the perimeter of the blob as the length of its boundary vectors.
`void`	`recolourIfSaturated(Image32 im32)` First tests isSaturatedInRegion() - if true, looks at the boundary to find average ratios of bands, then adjusts the saturated pixels upwards to have the same ratios.
`void`	`remeasureAccurately(BlobMeas meas, Image image)`
`void`	`remeasureAccurately(BlobMeas meas, ImFrame parentFrame)`
`void`	`setMeasuringRingSizeFactor(float factor)` Set the factor by which the measuring circles in display () are expanded.
`java.lang.String`	`toString()` Get a simple description of the Blob
`java.lang.StringBuffer`	`toXML(java.lang.String indent)` The indent string would typically contain some tab characters (\t).
`void`	`translate(int dx, int dy)` Move the blob by the given pixel displacement.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - Blob_
```
public Blob_(java.util.List<java.awt.Point> aBoundary,
             byte[][] mask)
```
    Construct a Blob from a boundary (list of points) and a mask. Detected pixels in the mask must have the value 3 and all others value 0 at the start.
  - Blob_
```
public Blob_(int x,
             int y)
```
    Construct a 1-pixel blob at (x, y) - for a detected pixel with no neighbours.
- Method Detail
  - getBoundary
```
public java.util.List<java.awt.Point> getBoundary()
```
    Specified by:
    
    getBoundary in interface Blob
  - getRows
```
public java.util.List<Blob_.BlobRow> getRows()
```
    Representing the filled region, including the boundary.
  - getRegion
```
public java.util.List<Blob_.BlobRow> getRegion()
```
  - nullRows
```
protected void nullRows()
```
    Available for saving memory if the boundary has to be kept but we no longer need the region. Use with care - make any measurements first!
  - hasRows
```
public boolean hasRows()
```
    Description copied from interface: Blob
    
    Whether region comprises at least one row.
    
    Specified by:
    
    hasRows in interface Blob
  - longestLine
```
public LineSegment longestLine()
```
    Find the two points on the boundary which are furthest apart from each other, returning the result as a LineSegment.
    
    Specified by:
    
    longestLine in interface Blob
  - getBrightnessDisc
```
public Blob getBrightnessDisc()
```
    For accurate brightness measurement in BlobMenu. The brightness disc is created when displaying a single blob in its own frame, by using display () in this class.
    
    Specified by:
    
    getBrightnessDisc in interface Blob
  - getBackgroundDisc
```
public Blob getBackgroundDisc()
```
    For accurate brightness measurement in BlobMenu. The background disc is created when displaying a single blob in its own frame, by using display () in this class.
    
    Specified by:
    
    getBackgroundDisc in interface Blob
  - isSaturatedInRegion
```
public boolean isSaturatedInRegion(ImFrame srcFrame)
```
    Rescan the region (rows) of this blob to determine whether it is saturated (ie, reaching maximum level in any band).
    
    Specified by:
    
    isSaturatedInRegion in interface Blob
  - isSaturatedInRegion
```
public boolean isSaturatedInRegion(Image srcImage)
```
    Rescan the region (rows) of this blob to determine whether it is saturated (ie, reaching maximum level in any band).
    
    Specified by:
    
    isSaturatedInRegion in interface Blob
  - recolourIfSaturated
```
public void recolourIfSaturated(Image32 im32)
```
    First tests isSaturatedInRegion() - if true, looks at the boundary to find average ratios of bands, then adjusts the saturated pixels upwards to have the same ratios. Unsaturated pixels are unaffected. NB: Only available for Image32.
    
    Specified by:
    
    recolourIfSaturated in interface Blob
  - toString
```
public java.lang.String toString()
```
    Get a simple description of the Blob
    
    Overrides:
    
    toString in class java.lang.Object
  - toXML
```
public java.lang.StringBuffer toXML(java.lang.String indent)
```
    The indent string would typically contain some tab characters (\t).
    
    Specified by:
    
    toXML in interface Blob
  - getVerticalCentreLineFromBoundary
```
public java.util.List<PointFloat> getVerticalCentreLineFromBoundary()
```
    Get a list of the centre points of all horizontal rows that comprise the blob with a simple shape. y values should be consecutive whole numbers. The blob must only have at most 2 boundary points on any horizontal line, except on the uppermost and lowermost lines which are excluded.
    
    Specified by:
    
    getVerticalCentreLineFromBoundary in interface Blob
  - getVerticalCentreLineFromRegion
```
public java.util.List<PointFloat> getVerticalCentreLineFromRegion()
```
    Get a list of the centre points of all horizontal rows that comprise the blob. y values should be consecutive whole numbers.
    
    Specified by:
    
    getVerticalCentreLineFromRegion in interface Blob
  - erase
```
public void erase(byte[][] mask)
```
    Erase this blob from a given mask.
    
    Specified by:
    
    erase in interface Blob
  - getBounds
```
public Bounds getBounds()
```
    Get the bounds of this Blob.
    
    Specified by:
    
    getBounds in interface Blob
  - drawBoundary
```
public void drawBoundary(Image image,
                         int[] levels)
```
    Draw the boundary of the blob in the given image with the given levels.
    
    Specified by:
    
    drawBoundary in interface Blob
  - drawBoundary
```
public void drawBoundary(byte[][] mask,
                         byte value)
```
    Draw the boundary of the blob in the mask array with the given value.
    
    Specified by:
    
    drawBoundary in interface Blob
  - drawRegion
```
public void drawRegion(Image image,
                       int[] levels)
```
    Draw the rows of the blob in the given image with the given levels.
    
    Specified by:
    
    drawRegion in interface Blob
  - drawRegion
```
public void drawRegion(byte[][] mask,
                       byte value)
```
    Draw the rows of the blob in the mask array with the given value.
    
    Specified by:
    
    drawRegion in interface Blob
  - boundaryMedianLevel
```
public int[] boundaryMedianLevel(Image image)
```
    Get the median level in each channel around the boundary in the given image.
    
    Specified by:
    
    boundaryMedianLevel in interface Blob
  - brightness
```
public int[] brightness(Image image)
```
    Measure the integrated detected brightness (NOT the average) in each channel
    
    Specified by:
    
    brightness in interface Blob
  - area
```
public int area()
```
    Measure the area of the blob, as the total number of pixels in its rows.
    
    Specified by:
    
    area in interface Blob
  - perimeter
```
public double perimeter()
```
    Measure the perimeter of the blob as the length of its boundary vectors.
    
    Specified by:
    
    perimeter in interface Blob
  - maskCentre
```
public PointFloat maskCentre()
```
    Calculate the centre of the blob simply as average of detected x and y, with no weighting from pixel densities.
    
    Specified by:
    
    maskCentre in interface Blob
  - densityCentre
```
public PointFloat densityCentre(Image image)
```
    Calculate the centre of the blob with weighting from pixel densities (brightnesses). Brightnesses simply sum all channels (R,G, B given equal weight).
    
    Specified by:
    
    densityCentre in interface Blob
  - measure
```
public BlobMeas measure(Image image)
```
    Measure brightness, density-weighted centre and area (pixel count) all on one pass. 2/10/09: Modified so that brightness combines channels not just by adding but as the square of the sum of the square of channel brightnesses.
    
    Specified by:
    
    measure in interface Blob
  - remeasureAccurately
```
public void remeasureAccurately(BlobMeas meas,
                                ImFrame parentFrame)
```
    Specified by:
    
    remeasureAccurately in interface Blob
  - remeasureAccurately
```
public void remeasureAccurately(BlobMeas meas,
                                Image image)
```
  - eraseToBackground
```
public void eraseToBackground(BlobMeas meas,
                              ImFrame parentFrame)
```
    For removing stars during comet stacking.
  - measureAccurately
```
public void measureAccurately(BlobMeas meas,
                              ImFrame parentFrame)
```
    Measure meanBackground, accurateBrightnesses and snRatios fields of the given BlobMeas using backgroundDisc and brightnessDisc in the given frame (which is assumed to be the parent frame of the magnified blob frame).
    The signal-to-noise (S/N) ratio for each channel is measured as
    (mean (starBrightness) - mean (backgroundBrightness)) / stdDev (backgroundBrightness)
    where mean (starBrightness) is the accurately measured brightness in the inner disc divided by the number of pixels in that disc. The signal is thus measured by the amount by which the star profile sticks up above the background. The noisiness of the background is measured by its standard deviation.
    
    Specified by:
    
    measureAccurately in interface Blob
  - measureAccurately
```
public void measureAccurately(BlobMeas meas,
                              Image image)
```
    Description copied from interface: Blob
    
    Measure meanBackground, accurateBrightnesses and snRatios fields of the given BlobMeas using backgroundDisc and brightnessDisc in the given frame (which is assumed to be the parent frame of the magnified blob frame).
    The signal-to-noise (S/N) ratio for each channel is measured as
    (mean (starBrightness) - mean (backgroundBrightness)) / stdDev (backgroundBrightness)
    where mean (starBrightness) is the accurately measured brightness in the inner disc divided by the number of pixels in that disc. The signal is thus measured by the amount by which the star profile sticks up above the background. The noisiness of the background is measured by its standard deviation.
    
    Specified by:
    
    measureAccurately in interface Blob
  - getMeasuringRingSizeFactor
```
public float getMeasuringRingSizeFactor()
```
    Get the factor by which the measuring circles in display () are expanded. The factor is static, so changing it for one blob affects all subsequent accurate measurements.
    
    Specified by:
    
    getMeasuringRingSizeFactor in interface Blob
  - setMeasuringRingSizeFactor
```
public void setMeasuringRingSizeFactor(float factor)
```
    Set the factor by which the measuring circles in display () are expanded. The factor is static, so changing it for one blob affects all subsequent accurate measurements.
    
    Specified by:
    
    setMeasuringRingSizeFactor in interface Blob
  - display
```
public BlobFrame display(ImFrame srcFrame,
                         BlobMeas meas)
```
    Display this blob magnified in a new BlobFrame. Boundary and lines through centre of gravity of the detected blob are overlaid. Returns reference to the BlobFrame (magnified ImFrame) that is displayed, so the caller could dispose of it.
    
    Specified by:
    
    display in interface Blob
  - getDisc
```
protected Blob getDisc(int radius,
                       int imWd,
                       int imHt,
                       byte value)
```
    Get a blob describing a solid disc of given radius in the centre of a rectangle of given width and height. This also sets values in the brightnessMask array and it is important to call this for the background disc before calling it for the brightness of the blob itself.
  - translate
```
public void translate(int dx,
                      int dy)
```
    Move the blob by the given pixel displacement.
    
    Specified by:
    
    translate in interface Blob

Class Blob_

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Blob_

Blob_

Method Detail

getBoundary

getRows

getRegion

nullRows

hasRows

longestLine

getBrightnessDisc

getBackgroundDisc

isSaturatedInRegion

isSaturatedInRegion

recolourIfSaturated

toString

toXML

getVerticalCentreLineFromBoundary

getVerticalCentreLineFromRegion

erase

getBounds

drawBoundary

drawBoundary

drawRegion

drawRegion

boundaryMedianLevel

brightness

area

perimeter

maskCentre

densityCentre

measure

remeasureAccurately

remeasureAccurately

eraseToBackground

measureAccurately

measureAccurately

getMeasuringRingSizeFactor

setMeasuringRingSizeFactor

display

getDisc

translate