com.googlecode.leptonica.android

Class Skew

com.googlecode.leptonica.android.Skew

public class Skew

Image rotation and skew detection methods.

Field Detail

SWEEP_RANGE

public static float SWEEP_RANGE

Default range for sweep, will detect rotation of + or - 30 degrees.

See Also:

Constant Field Values

SWEEP_DELTA

public static float SWEEP_DELTA

Default sweep delta, reasonably accurate within 0.05 degrees.

See Also:

Constant Field Values

SWEEP_REDUCTION

public static int SWEEP_REDUCTION

Default sweep reduction, one-eighth the size of the original image.

See Also:

Constant Field Values

SEARCH_REDUCTION

public static int SEARCH_REDUCTION

Default sweep reduction, one-fourth the size of the original image.

See Also:

Constant Field Values

SEARCH_MIN_DELTA

public static float SEARCH_MIN_DELTA

Default search minimum delta, reasonably accurate within 0.05 degrees.

See Also:

Constant Field Values

Method Detail

findSkew

public static float findSkew(Pix pixs)

Finds and returns the skew angle using default parameters.

Parameters:

pixs - Input pix (1 bpp).

Returns:

org.jetbrains.dokka.NodeRenderContent@637f69a7: the detected skew angle, or 0.0 on failure

findSkew

public static float findSkew(Pix pixs,
                             float sweepRange,
                             float sweepDelta,
                             int sweepReduction,
                             int searchReduction,
                             float searchMinDelta)

Finds and returns the skew angle, doing first a sweep through a set of equal angles, and then doing a binary search until convergence.

Notes:

1. In computing the differential line sum variance score, we sum the result over scanlines, but we always skip:
   • at least one scanline
   • not more than 10% of the image height
   • not more than 5% of the image width

Parameters:

pixs - Input pix (1 bpp).

sweepRange - Half the full search range, assumed about 0; in degrees.

sweepDelta - Angle increment of sweep; in degrees.

sweepReduction - Sweep reduction factor = 1, 2, 4 or 8.

searchReduction - Binary search reduction factor = 1, 2, 4 or 8; and must not exceed sweepReduction.

searchMinDelta - Minimum binary search increment angle; in degrees.

Returns:

org.jetbrains.dokka.NodeRenderContent@557b2c27: the detected skew angle, or 0.0 on failure