com.googlecode.leptonica.android

Class Edge

java.lang.Object

com.googlecode.leptonica.android.Edge

public class Edge
extends Object

Edge detection.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	Edge.EdgeOrientationFlag

Field Summary

Fields

Modifier and Type	Field and Description
static int	L_ALL_EDGES Filters for all edges
static int	L_HORIZONTAL_EDGES Filters for horizontal edges
static int	L_VERTICAL_EDGES Filters for vertical edges

Constructor Summary

Constructors

Constructor and Description
Edge()

Method Summary

Modifier and Type	Method and Description
static Pix	pixSobelEdgeFilter(Pix pixs, int orientFlag) Performs a Sobel edge detecting filter.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

L_HORIZONTAL_EDGES

public static final int L_HORIZONTAL_EDGES

Filters for horizontal edges

See Also:

Constant Field Values

L_VERTICAL_EDGES

public static final int L_VERTICAL_EDGES

Filters for vertical edges

See Also:

Constant Field Values

L_ALL_EDGES

public static final int L_ALL_EDGES

Filters for all edges

See Also:

Constant Field Values

Constructor Detail

Edge

public Edge()

Method Detail

pixSobelEdgeFilter

public static Pix pixSobelEdgeFilter(Pix pixs,
                                     int orientFlag)

Performs a Sobel edge detecting filter.

To use both the vertical and horizontal filters, set the orientation flag to L_ALL_EDGES; this sums the abs. value of their outputs, clipped to 255.

Notes:

1. Invert pixd to see larger gradients as darker (grayscale).
2. To generate a binary image of the edges, threshold the result using pixThresholdToBinary(). If the high edge values are to be fg (1), invert after running pixThresholdToBinary().
3. Label the pixels as follows:

   1 4 7

   2 5 8

   3 6 9

   Read the data incrementally across the image and unroll the loop.

4. This runs at about 45 Mpix/sec on a 3 GHz processor.

Parameters:

pixs - Source pix (8 bpp; no colormap)

orientFlag - Edge orientation flag (L_HORIZONTAL_EDGES, L_VERTICAL_EDGES, L_ALL_EDGES)

Returns:

a new Pix image (8bpp, edges are brighter), or null on error