dots_imagedots_imageDotsImagedots_imageDotsImageDotsImage (Operator)

Name

dots_imagedots_imageDotsImagedots_imageDotsImageDotsImage — Enhance circular dots in an image.

Signature

dots_image(Image : DotImage : Diameter, FilterType, PixelShift : )

dots_imagedots_imageDotsImagedots_imageDotsImageDotsImage enhances circular dots of diameter DiameterDiameterDiameterDiameterDiameterdiameter in the input image ImageImageImageImageImageimage. Hence, dots_imagedots_imageDotsImagedots_imageDotsImageDotsImage is especially suited for the segmentation of dot prints, e.g., in OCR applications. The enhancement is performed by using matched filters with filter masks that are tuned for a particular dot size. For example, for DiameterDiameterDiameterDiameterDiameterdiameter = 5 the filter mask is given by:

      |         -21 -21 -21         |
      |     -21  16  16  16 -21     |
 1    | -21  16  16  16  16  16 -21 |
--- * | -21  16  16  16  16  16 -21 |
336   | -21  16  16  16  16  16 -21 |
      |     -21  16  16  16 -21     |
      |         -21 -21 -21         |

The parameter FilterTypeFilterTypeFilterTypeFilterTypeFilterTypefilterType selects whether 'dark'"dark""dark""dark""dark""dark", 'light'"light""light""light""light""light", or 'all'"all""all""all""all""all" dots in the image should be enhanced. The PixelShiftPixelShiftPixelShiftPixelShiftPixelShiftpixelShift can be used either to increase the contrast of the output image (PixelShiftPixelShiftPixelShiftPixelShiftPixelShiftpixelShift > 0) or to dampen the values in extremly bright areas that would be cut off otherwise (PixelShiftPixelShiftPixelShiftPixelShiftPixelShiftpixelShift = -1).

Parallelization

Multithreading type: reentrant (runs in parallel with non-exclusive operators).
Multithreading scope: global (may be called from any thread).
Automatically parallelized on tuple level.
Automatically parallelized on channel level.
Automatically parallelized on domain level.

Parameters

ImageImageImageImageImageimage (input_object) (multichannel-)image(-array) → object (byte / uint2)

Input image.

DotImageDotImageDotImageDotImageDotImagedotImage (output_object) (multichannel-)image(-array) → object (byte / uint2)

Output image.

DiameterDiameterDiameterDiameterDiameterdiameter (input_control) integer → (integer)

Diameter of the dots to be enhanced.

Default value: 5

List of values: 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23

FilterTypeFilterTypeFilterTypeFilterTypeFilterTypefilterType (input_control) string → (string)

Enhance dark, light, or all dots.

Default value: 'light' "light" "light" "light" "light" "light"

List of values: 'all'"all""all""all""all""all", 'dark'"dark""dark""dark""dark""dark", 'light'"light""light""light""light""light"

PixelShiftPixelShiftPixelShiftPixelShiftPixelShiftpixelShift (input_control) integer → (integer)

Shift of the filter response.

Default value: 0

List of values: -1, 0, 1, 2

Possible Successors

thresholdthresholdThresholdthresholdThresholdThreshold

Alternatives

laplacelaplaceLaplacelaplaceLaplaceLaplace, laplace_of_gausslaplace_of_gaussLaplaceOfGausslaplace_of_gaussLaplaceOfGaussLaplaceOfGauss, diff_of_gaussdiff_of_gaussDiffOfGaussdiff_of_gaussDiffOfGaussDiffOfGauss, derivate_gaussderivate_gaussDerivateGaussderivate_gaussDerivateGaussDerivateGauss, convol_imageconvol_imageConvolImageconvol_imageConvolImageConvolImage

Module

Foundation

Operators