MedgeDraw

Board	Supported
Host System	Yes
V4L2	Yes
Clarity UHD	Yes
Concord PoE	No
GenTL	Yes
GevIQ	Yes
GigE Vision	Yes
Indio	No
Iris GTX	Yes
Radient eV-CL	Yes
Rapixo CL	Yes
Rapixo CoF	Yes
Rapixo CXP	Yes
USB3 Vision	Yes

Draw specific edge results in the destination image buffer or 2D graphics list.

Syntax

void MedgeDraw(
    AIL_ID    ContextGraId,            //in
    AIL_ID    ResultEdgeId,            //in
    AIL_ID    DstImageBufOrListGraId,  //out
    AIL_INT64 Operation,               //in
    AIL_INT   IndexOrLabel,            //in
    AIL_INT64 ControlFlag              //in
)

Description

This function draws specific edge results in the destination image buffer or 2D graphics list.

To draw edge results, the required information must be available for the specified edge or group of edges, in the Edge Finder result buffer. To verify availability, call MedgeGetResult with the required edge result combined with M_AVAILABLE.

You can draw results and settings, obtained relative to an offset, at the top-left corner of the destination image, using MgraControl with M_DRAW_OFFSET_X and M_DRAW_OFFSET_Y and zoom them using MgraControl withM_DRAW_ZOOM_X and M_DRAW_ZOOM_Y. For example, you can draw a zoomed section of the edge map found in the target image at the top-left corner of the destination image. For more information, see Drawing with an offset and scale.

[Image: medgezooming.png]

Note that if the edges are calculated using a calibrated source image, Edge Finder takes the camera calibration into account; that is, drawings might be distorted, according to the camera calibration. For example, a straight line (in the world) might be drawn as a curve.

Parameters

ContextGraId (in, AIL_ID)

Specifies the identifier of the 2D graphics context to use when drawing. This parameter must be set to one of the following values:

For specifying the 2D graphics context

Value	Description
M_DEFAULT	Specifies that the default 2D graphics context of the current Aurora Imaging Library application is used.

Note: Note that there is a different default 2D graphics context for each thread. | | 2D graphics context identifier | Specifies a valid 2D graphics context identifier, which you have allocated using MgraAlloc. |

ResultEdgeId (in, AIL_ID)

Specifies the identifier of the Edge Finder result buffer from which to extract the results to draw. The Edge Finder result buffer must have been previously allocated on the required system using MedgeAllocResult.

DstImageBufOrListGraId (out, AIL_ID)

Specifies the identifier of the destination image buffer or 2D graphics list in which to draw. The buffer can be any valid 1- or 3-band image buffer allocated using MbufAlloc.... The 2D graphics list must be previously allocated using MgraAllocList. By drawing into a display's overlay buffer or associating the 2D graphics list with the display, you can also annotate an image non-destructively.

Operation (in, AIL_INT64)

Specifies the type of operation to perform. The possible Operation parameter values in the table below can be added together to draw multiple feature results at once.

For specifying the type of operation to perform

Value	Description
M_DRAW_BOX	Draws a bounding box around each edge.

Note that to perform this operation, the M_BOX feature in MedgeControl must be calculated. | | M_DRAW_CENTER_OF_GRAVITY | Draws a cross at the center of gravity of each edge.

Note that to perform this operation, the M_CENTER_OF_GRAVITY feature in MedgeControl must be calculated. | | M_DRAW_CIRCLE_FIT | Draws the circle fit of each edge.

Note that to perform this operation, the M_CIRCLE_FIT feature in MedgeControl must be calculated. | | M_DRAW_EDGE | Draws each edge. | | M_DRAW_EDGELS | Draws a cross at each edgel. | | M_DRAW_ELLIPSE_FIT | Draws the ellipse fit of each edge.

Note that to perform this operation, the M_ELLIPSE_FIT feature in MedgeControl must be calculated. | | M_DRAW_FERET_GENERAL | Draws the edges' general Feret, using an H-type line (|-|). This line is drawn on contact with the edge's two extrema edgels, at the general Feret diameter's angle.

Note that to perform this operation, the M_FERET_GENERAL feature in MedgeControl must be calculated. | | M_DRAW_FERET_MAX | Draws the edges' maximum Feret, using an H-type line (|-|). This line is drawn on contact with the edge's two extrema edgels, at the maximum Feret diameter's angle.

Note that to perform this operation, the M_FERET_MAX_DIAMETER and M_FERET_MAX_ANGLE features in MedgeControl must be calculated. | | M_DRAW_FERET_MIN | Draws the edges' minimum Feret, using an H-type line (|-|). This line is drawn on contact with the edge's two extrema edgels, at the minimum Feret diameter's angle.

Note that to perform this operation, the M_FERET_MIN_DIAMETER and M_FERET_MIN_ANGLE features in MedgeControl must be calculated. | | M_DRAW_INDEX | Draws each edge's index value.

Note that this operation will only work for included edges. Therefore the IndexOrLabel parameter cannot be set to M_EXCLUDED_EDGES and can only be set to M_ALL_EDGES if all edges are included. | | M_DRAW_LABEL | Draws each edge's label value.

Note that to perform this operation, the M_LABEL_VALUE feature in MedgeControl must be calculated. | | M_DRAW_LINE_FIT | Draws the line fit of each edge.

Note that to perform this operation, the M_LINE_FIT feature in MedgeControl must be calculated. | | M_DRAW_POSITION | Draws a cross at the center of each edge.

Note that to perform this operation, the M_POSITION feature in MedgeControl must be calculated. | | M_DRAW_SEGMENTS | Draws the segments of the edge approximation.

Note that to perform this operation, edge approximations must have been previously calculated by setting MedgeControl with M_CHAIN_APPROXIMATION to M_LINE or M_WORLD_LINE. | | M_DRAW_VERTICES | Draws the segment intersections (or vertices) of the edge approximation.

Note that to perform this operation, edge approximations must have been previously calculated by setting MedgeControl with M_CHAIN_APPROXIMATION to M_LINE or M_WORLD_LINE. |

For

Value	Description
M_DRAW_VALUE	Specifies that the operation's numerical value is drawn. For example, if you add M_DRAW_VALUE to M_DRAW_CENTER_OF_GRAVITY, the center of gravity's coordinates are drawn within parenthesis, and centered above the drawing cross.

For specifying operations that cannot use a 2D graphics list as a destination

Value	Description
M_DRAW_ANGLE	Draws the internal angle buffer.

Note that to perform this operation, the angle buffer must have been previously saved in the result buffer by enabling M_SAVE_ANGLE in MedgeControl. | | M_DRAW_CROSS_DERIVATIVE | Draws the internal cross-derivative buffer of the source image.

M_DRAW_CROSS_DERIVATIVE is only relevant for M_CREST Edge Finder contexts. | | M_DRAW_FIRST_DERIVATIVE_X | Draws the internal first derivative buffer of the source image, in the X-direction.

M_DRAW_FIRST_DERIVATIVE_X is only relevant for M_CONTOUR Edge Finder contexts. | | M_DRAW_FIRST_DERIVATIVE_Y | Draws the internal first derivative buffer of the source image, in the Y-direction.

M_DRAW_FIRST_DERIVATIVE_Y is only relevant for M_CONTOUR Edge Finder contexts. | | M_DRAW_IMAGE | Draws the source image.

Note that to perform this operation, the source image must have been previously saved in the result buffer by enabling M_SAVE_IMAGE in MedgeControl. | | M_DRAW_MAGNITUDE | Draws the internal magnitude buffer.

Note that to perform this operation, the magnitude buffer must have been previously saved in the result buffer by enabling M_SAVE_MAGNITUDE in MedgeControl. | | M_DRAW_MASK | Draws the mask buffer.

Note that to perform this operation, the mask buffer must have been previously saved in the result buffer by enabling M_SAVE_MASK in MedgeControl. | | M_DRAW_SECOND_DERIVATIVE_X | Draws the internal second derivative buffer of the source image, in the X-direction.

M_DRAW_SECOND_DERIVATIVE_X can only be used with M_CREST Edge Finder contexts. | | M_DRAW_SECOND_DERIVATIVE_Y | Draws the internal second derivative buffer of the source image, in the Y-direction.

M_DRAW_SECOND_DERIVATIVE_Y can only be used with M_CREST Edge Finder contexts. |

IndexOrLabel (in, AIL_INT)

Specifies the edge(s) to draw. This parameter must be set to one of the values below.

For specifying the edge(s) to draw

Value	Description
M_DEFAULT	Same as M_INCLUDED_EDGES.
M_ALL_EDGES	Specifies all edges.
M_EXCLUDED_EDGES	Specifies all currently excluded edges.
M_INCLUDED_EDGES	Specifies all currently included edges.
Value	Specifies either the edge's index or label. For more information, see combination values below.

Valid index values must fall within the following range: 0 to the number of included edges in the Edge Finder result buffer - 1. You can retrieve valid label values using MedgeGetResult with M_LABEL_VALUE. |

For an index or a label value

Value	Description
M_TYPE_INDEX (default)	Specifies an edge using its index value.

Note that only included edges (M_INCLUDED_EDGES) can be drawn. | | M_TYPE_LABEL | Specifies an edge using its label value. |

ControlFlag (in, AIL_INT64)

Reserved for future expansion and must be set to M_DEFAULT.

Note that to perform this operation, the derivatives must have been previously saved in the result buffer by enabling M_SAVE_DERIVATIVES in MedgeControl.

You can modify the cross size by setting MedgeControl with M_DRAW_CROSS_SIZE to an appropriate value.