com.googlecode.leptonica.android

Class Edge

com.googlecode.leptonica.android.Edge

public class Edge

Edge detection.

Field Detail

L_HORIZONTAL_EDGES

public static int L_HORIZONTAL_EDGES

Filters for horizontal edges

See Also:

Constant Field Values

L_VERTICAL_EDGES

public static int L_VERTICAL_EDGES

Filters for vertical edges

See Also:

Constant Field Values

L_ALL_EDGES

public static int L_ALL_EDGES

Filters for all edges

See Also:

Constant Field Values

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:

org.jetbrains.dokka.NodeRenderContent@434ff58f: a new Pix image (8bpp, edges are brighter), or null on error