Replace Blob
The replace blob module will replace white blobs present in the current image with the specified color
object shape as selected in the interface. The shapes' sizes will be based on the area of the blob
being replaced. This module is useful if you want to better define the shape of the blob with a
known shape. For example, replacing detected blobs with a better defined circle can aid in subsequent
detection or analysis.
Interface
Instructions
1. Color  Select the color the replaced shape will appear in. "mean" (last color) will cause the shape to be drawn in the
average color of the original blob.
2. Shape  Select the shape that is used to replace each blob present in the image.
bounding box  replaces each blob with it bounding box extents (xmax, ymax, xmin, ymin) 
minimal enclosure  replaces each blob with its minimal enclosure parallelogram (rectangle) 
circular enclosure  replaces each blob with a circle that encompasses the entire blob (aka Circumscribed Circle) 
inscribed circle  replaces each blob with the largest inner circle that fits into the blob 
crosshair  marks each blob's center of gravity with a cross hair 
square area  replaces each blob with a square of the same area centered at the center of gravity of the blob 
circle area  replaces each blob with a circle of the same area centered at the center of gravity of the blob 
triangle area  replaces each blob with a triangle of the same area centered at the center of gravity of the blob 
star area  replaces each blob with a star of the same area centered at the center of gravity of the blob 
diamond area  replaces each blob with a diamond of the same area centered at the center of gravity of the blob 
inner square  replaces each blob with the largest Cartesian (not rotated) square that fits in the blob 
inner rectangle  replaces each blob with the largest Cartesian (not rotated) rectangle that fits in the blob 
minimal quadrilateral  replaces each blob with the largest 4 sides polygon that fits around the blob 
minimal parallelogram  replaces each blob with the largest parallelogram that fits around the blob 
ellipse  replaces each blob with an ellipse 
best fit rectangle  uses a best fit algorithm to create 4 lines that best represent all the edge points of the blob 
3. Thickness  If the shape is drawn as lines this specifies how thick the drawn line should be.
4. Fill Shape  Select if you want the object shape to be filled in.
5. Overlay  Select what the resulting graphic will be drawn on.
Source  the original captured image
Current  the current image seen at this point in the processing pipeline
XXX  other images created by the Marker module.
6. Order  Each replace creates variables (see below) that contain the values that represent the replaced blob. The order
of these blobs and thus their numerical results can be changed by selecting the order checkboxes. For example, if you
want to order the array in increasing X then select the "Order array based on X" which will sort the blobs
in increasing X order. This can be handy if you are relying on a specific order of the blobs in order to continue
processing in subsequent modules or scripts.
Example
Source  Minimal Quadrilateral 
 
The example above shows an image RGBFiltered, Dilated and then blob replaced with red circles. Notice
how the red traffic light is now better pronounced than in the source image.
Variables
BLOB_REPLACE_COORDINATES  duplicate array from one of the following arrays. Can be used
to avoid having to rename array references when switching between different replace
methods.
BOUNDING_COORDINATES  p1x, p1y, p2x, p2y, p3x, p3y, p4x, p4y coordinates of the Bounding
Box of the replaced blob when this is selected. Note that this is an ARRAY with
8 numbers per blob.
CROSSHAIR_COORDINATES  x, y coordinates of the CrossHair that replaces a blob
when this replace method is selected. Note that this is an ARRAY with 2 numbers
per replaced blob.
SQUARE_COORDINATES  p1x, p1y, p2x, p2y, p3x, p3y, p4x, p4y coordinates of the Square
that replaces the blob when this is selected. Note that this is an ARRAY with
8 numbers per blob.
CIRCLE_COORDINATES  x, y, radius of the Circle that replaces the blob when this is
selected. Note that this is an ARRAY with 3 numbers per blob.
TRIANGLE_COORDINATES  x, y, base of the Triangle that replaces the blob when this is
selected. Note that this is an ARRAY with 3 numbers per blob.
STAR_COORDINATES  x, y, radius of the Star that replaces the blob when this is
selected. Note that this is an ARRAY with 3 numbers per blob.
DIAMOND_COORDINATES  x, y, radius of the Diamond that replaces the blob when this is
selected. Note that this is an ARRAY with 3 numbers per blob.
BFR_COORDINATES  p1x, p1y, p2x, p2y, p3x, p3y, p4x, p4y coordinates of the Best Fit
Rectangle of the replaced blob when this is selected. Note that this is an ARRAY with
8 numbers per blob.
MEQ_COORDINATES  p1x, p1y, p2x, p2y, p3x, p3y, p4x, p4y coordinates of the Minimal
Quadrilateral of the replaced blob when this is selected. Note that this is an ARRAY with
8 numbers per blob.
MER_COORINATES  p1x, p1y, p2x, p2y, p3x, p3y, p4x, p4y coordinates of the Minimal Enclosed
Rectangle for each detected blob when the . Note that this is an ARRAY with 8 numbers per blob.
MEP_COORINATES  p1x, p1y, p2x, p2y, p3x, p3y, p4x, p4y coordinates of the Minimal Enclosed
Polygon for each detected blob. Note that this is an ARRAY with 8 numbers per blob.
See Also
Convex Hull
Smooth Hull
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