PK - Peak search

PURPOSE

Searches for local peaks in an image.

SEE ALSO

PK 3	[Peak search - 3D]
PK 3D	[Peak search - 3D, output to Document file]
PK C	[Peak search - Center of gravity]
PK D	[Peak search - output to Document file]
PK M	[Peak search - Maximum]
PK DC	[Peak search - Center of gravity, output to Document file]

USAGE

.OPERATION: PK [ix],[iy],[pk],[ratio], [xp],[yp],[pkp]

[The first three optional output parameters (in this example [ix],[iy],[pk]) specify registers that are to receive the coordinates (integer values) and the value of the largest peak found in this operation. The 4th register (here [ratio]) contains the ratio of the first peak relative to the peak # specified for that ratio (option: ORIGIN OVERRIDE). The 5th & 6th registers (here [xp],[yp]) return the non-integer coordinates according to a 9-point parabolic fit, and the last register (here [pkp]) contains the value of that maximum.]

.INPUT FILE: PIC001
[Enter name of the input image.]

.ENTER # OF PEAKS, CENTER ORIGIN OVERRIDE (0/1): 12, 0
[Enter the number of peaks to be searched for. If an origin position other than at the picture's center (NX/2 + 1, NY/2 + 1) is desired, enter '1' in the second position. The system will then allow you to enter the X,Y coordinates of the origin to be used.]

If the option "CENTER ORIGIN OVERRIDE" is specified the following two questions appear:

.NEW ORIGIN COORDINATES: 1,1
[Enter the new origin coordinates.]

.ENTER PEAK NUMBER FOR RATIO: 1
[Enter the number of the peak relative to which the heights of the other peaks are calculated. This ratio is printed out and listed in the document file along with the other parameters of the peaks.]

NOTES

1. In the above example, the computer will find the 12 largest peaks. These positions will be printed in the RESULTS file, and the position of the largest peak will be printed to the user's terminal. Optionally, the peak positions and values will be put into the register variables if requested.

2. This routine does NOT find "maximum" location when image has plateaus. It may even find the "last" value along the plateau. To overcome this use low pass filtration first or use 'PK M'.

3. The register variables from the command line (if any) can be used as input to a subsequent 'SH' (SHIFT) operation.

SUBROUTINES

SPEAK, PARABL

CALLER

UTIL1