gen_gauss_pyramidgen_gauss_pyramidGenGaussPyramidGenGaussPyramidgen_gauss_pyramid (Operator)

Name

gen_gauss_pyramidgen_gauss_pyramidGenGaussPyramidGenGaussPyramidgen_gauss_pyramid — Calculating a Gauss pyramid.

Signature

gen_gauss_pyramid(Image : ImagePyramid : Mode, Scale : )

Description

The operator gen_gauss_pyramidgen_gauss_pyramidGenGaussPyramidGenGaussPyramidGenGaussPyramidgen_gauss_pyramid calculates a pyramid of scaled down images. The scale by which the next image will be reduced is determined by the parameter ScaleScaleScaleScalescalescale. For instance, a value of 0.5 for ScaleScaleScaleScalescalescale will shorten the edge length of ImageImageImageImageimageimage by 50%. This is exactly equivalent to the “normal” pyramid.

The parameter ModeModeModeModemodemode determines the way of averaging. For a more detailed description concerning this parameter see also affine_trans_imageaffine_trans_imageAffineTransImageAffineTransImageAffineTransImageaffine_trans_image. In the case that ScaleScaleScaleScalescalescale is equal 0.5 there are the additional modes 'min'"min""min""min""min""min" and 'max'"max""max""max""max""max" available. In this case the minimum or the maximum of the four neighboring pixels is selected.

Please note that each level will be returned as an individual image, i.e., as one iconic object, with one matrix and its own domain. Single or multiple levels can be selected by using select_objselect_objSelectObjSelectObjSelectObjselect_obj or copy_objcopy_objCopyObjCopyObjCopyObjcopy_obj, respectively.

Execution Information

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

Parameters

ImageImageImageImageimageimage (input_object) (multichannel-)image → object (byte / uint2 / real)

Input image.

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

Output images.

Number of elements: ImagePyramid > Image

ModeModeModeModemodemode (input_control) string → (string)

Kind of filter mask.

Default value: 'weighted' "weighted" "weighted" "weighted" "weighted" "weighted"

List of values: 'constant'"constant""constant""constant""constant""constant", 'max'"max""max""max""max""max", 'min'"min""min""min""min""min", 'nearest_neighbor'"nearest_neighbor""nearest_neighbor""nearest_neighbor""nearest_neighbor""nearest_neighbor", 'weighted'"weighted""weighted""weighted""weighted""weighted"

ScaleScaleScaleScalescalescale (input_control) real → (real)

Factor for scaling down.

Default value: 0.5

Suggested values: 0.2, 0.3, 0.4, 0.5, 0.6

Typical range of values: 0.1 ≤ Scale Scale Scale Scale scale scale ≤ 0.9

Minimum increment: 0.01

Recommended increment: 0.1

Restriction: 0.1 < Scale && Scale < 0.9

Example (C)

gen_gauss_pyramid(Image,Pyramid,"weighted",0.5);
count_obj(Pyramid,&num);
for (i=1; i<=num; i++)
{
  select_obj(Pyramid,&Single,i);
  disp_image(Single,WindowHandle);
  clear(Single);
}