clipm_priv_array.h File Reference

#include <cpl.h>

Go to the source code of this file.

Functions
cpl_array *	clipm_priv_array_new_from_image_row (const cpl_image *image, cpl_size row_ndx)
	Extract an image row and store it in an array. More...
cpl_array *	clipm_priv_array_new_from_image_col (const cpl_image *image, cpl_size col_ndx)
	Extract an image column and store it in an array. More...
double	clipm_priv_array_estimate_fwhm (const cpl_array *input, double centre, double bg_level, cpl_size *out_maxindex, double *out_middlepos, double *out_edgeslope)
	Search maximum from given centre position and find FWHM. More...
void	clipm_priv_array_null (cpl_array **a)
	Delete a CPL array object and set the pointer to NULL. More...

Function Documentation

double clipm_priv_array_estimate_fwhm	(	const cpl_array *	input,
		double	centre,
		double	bg_level,
		cpl_size *	out_maxindex,
		double *	out_middlepos,
		double *	out_edgeslope
	)

Search maximum from given centre position and find FWHM.

Parameters

input	Input vector
centre	Centre position
bg_level	Background level
out_maxindex	(Optional output) index of found maximum value, can be NULL
out_middlepos	(Optional output) middle position between left and right FWHM edges, can be NULL
out_edgeslope	(Optional output) steepness of the edges, returns -1.0 if unsuccessful, can be NULL

Returns

Full-width-half-maximum, -1.0 in the case of error

Principle:

• The maximum is searched in ascending direction.
• From the maximum's position, the borders where the signal falls below the mean of the maximum and bg_level are searched.
• If out_edgeslope is given, then the steepness is measured between the 30% and 70% percent levels. This is done for both end, if one fails, then the other value is returned, otherwise the mean of both.

Note

• out_maxindex does not return the position of the maximum value of the whole input vector, but of the maximum found by starting at centre.
• This function jumps over "bad" flagges regions.
• The FWHM is interpolated using non-bad values.
• If out_edgeslope can not be computed, NO error is set

Error Handling:

• In the case of error, all output values are set to -1.
• The following error codes can be set by this function:
  • CPL_ERROR_NULL_INPUT: input vector is NULL
  • CPL_ERROR_ACCESS_OUT_OF_RANGE: centre is outside the input vector range
  • CPL_ERROR_INVALID_TYPE: input is not of type CPL_TYPE_INT, CPL_TYPE_FLOAT or CPL_TYPE_DOUBLE
  • CPL_ERROR_CONTINUE: the FWHM could not be found, or the peak is not brighter than bg_level
  • CPL_ERROR_DATA_NOT_FOUND: too many bad pixels prevent the computation of the FWHM

Todo:

• Force _clipm_priv_vector_find_limits() to fail in unit test
• Check out_edgeslope in unit test, also with flat object

cpl_array* clipm_priv_array_new_from_image_col	(	const cpl_image *	image,
		cpl_size	col_ndx
	)

Extract an image column and store it in an array.

Parameters

image	Input image
col_ndx	Column index (FITS convention)

Returns

The new array

Bad Pixel Handling:

• Bad pixels will lead to invalid entried in the output array.

Error Handling:

The following errors can occur:

• CPL_ERROR_NULL_INPUT: image is NULL
• CPL_ERROR_INVALID_TYPE: image is not of type CPL_TYPE_INT, CPL_TYPE_FLOAT or CPL_TYPE_DOUBLE
• CPL_ERROR_ACCESS_OUT_OF_RANGE: col_ndx is outside the horizontal image range

cpl_array* clipm_priv_array_new_from_image_row	(	const cpl_image *	image,
		cpl_size	row_ndx
	)

Extract an image row and store it in an array.

Parameters

image	Input image
row_ndx	Row index (FITS convention)

Returns

The new array

Bad Pixel Handling:

• Bad pixels will lead to invalid entried in the output array.

Error Handling:

The following errors can occur:

• CPL_ERROR_NULL_INPUT: image is NULL
• CPL_ERROR_INVALID_TYPE: image is not of type CPL_TYPE_INT, CPL_TYPE_FLOAT or CPL_TYPE_DOUBLE
• CPL_ERROR_ACCESS_OUT_OF_RANGE: row_ndx is outside the vertical image range

void clipm_priv_array_null

(

cpl_array **

a

)

Delete a CPL array object and set the pointer to NULL.

Parameters

a	Pointer to array pointer

Returns

Nothing

The following code is executed:

   if (a != NULL)
   {
       cpl_array_delete(*a);  // checks for NULL pointer
       *a = NULL;
   }
* 

Error Handling:

No error can occur here.