Example #1
0
static void test_raster_metadata() {
	rt_raster raster = NULL;

	/* create raster */
	raster = rt_raster_new(5, 5);
	CU_ASSERT(raster != NULL);

	/* # of bands */
	CU_ASSERT_EQUAL(rt_raster_get_num_bands(raster), 0);

	/* has bands */
	CU_ASSERT(!rt_raster_has_band(raster, 1));

	/* upper-left corner */
	rt_raster_set_offsets(raster, 30, -70);
	CU_ASSERT_DOUBLE_EQUAL(rt_raster_get_x_offset(raster), 30, DBL_EPSILON);
	CU_ASSERT_DOUBLE_EQUAL(rt_raster_get_y_offset(raster), -70, DBL_EPSILON);

	/* scale */
	rt_raster_set_scale(raster, 10, -10);
	CU_ASSERT_DOUBLE_EQUAL(rt_raster_get_x_scale(raster), 10, DBL_EPSILON);
	CU_ASSERT_DOUBLE_EQUAL(rt_raster_get_y_scale(raster), -10, DBL_EPSILON);

	/* skew */
	rt_raster_set_skews(raster, 0.0001, -0.05);
	CU_ASSERT_DOUBLE_EQUAL(rt_raster_get_x_skew(raster), 0.0001, DBL_EPSILON);
	CU_ASSERT_DOUBLE_EQUAL(rt_raster_get_y_skew(raster), -0.05, DBL_EPSILON);

	/* srid */
	rt_raster_set_srid(raster, 4326);
	CU_ASSERT_EQUAL(rt_raster_get_srid(raster), 4326);
	rt_raster_set_srid(raster, 4269);
	CU_ASSERT_EQUAL(rt_raster_get_srid(raster), 4269);

	cu_free_raster(raster);
}
Example #2
0
static void test_raster_clone() {
	rt_raster rast1;
	rt_raster rast2;
	rt_band band;

	int maxX = 5;
	int maxY = 5;
	double gt[6];

	rast1 = rt_raster_new(maxX, maxY);
	CU_ASSERT(rast1 != NULL);

	rt_raster_set_offsets(rast1, 0, 0);
	rt_raster_set_scale(rast1, 1, -1);
	rt_raster_set_srid(rast1, 4326);

	band = cu_add_band(rast1, PT_32BUI, 1, 6);
	CU_ASSERT(band != NULL);

	/* clone without bands */
	rast2 = rt_raster_clone(rast1, 0);
	CU_ASSERT(rast2 != NULL);
	CU_ASSERT_EQUAL(rt_raster_get_num_bands(rast2), 0);

	rt_raster_get_geotransform_matrix(rast2, gt);
	CU_ASSERT_EQUAL(rt_raster_get_srid(rast2), 4326);
	CU_ASSERT_DOUBLE_EQUAL(gt[0], 0, DBL_EPSILON);
	CU_ASSERT_DOUBLE_EQUAL(gt[1], 1, DBL_EPSILON);
	CU_ASSERT_DOUBLE_EQUAL(gt[2], 0, DBL_EPSILON);
	CU_ASSERT_DOUBLE_EQUAL(gt[3], 0, DBL_EPSILON);
	CU_ASSERT_DOUBLE_EQUAL(gt[4], 0, DBL_EPSILON);
	CU_ASSERT_DOUBLE_EQUAL(gt[5], -1, DBL_EPSILON);

	cu_free_raster(rast2);

	/* clone with bands */
	rast2 = rt_raster_clone(rast1, 1);
	CU_ASSERT(rast2 != NULL);
	CU_ASSERT_EQUAL(rt_raster_get_num_bands(rast2), 1);

	cu_free_raster(rast2);
	cu_free_raster(rast1);
}
Example #3
0
/**
 * n-raster iterator.
 * The raster returned should be freed by the caller
 *
 * @param itrset : set of rt_iterator objects.
 * @param itrcount : number of objects in itrset.
 * @param extenttype : type of extent for the output raster.
 * @param customextent : raster specifying custom extent.
 * is only used if extenttype is ET_CUSTOM.
 * @param pixtype : the desired pixel type of the output raster's band.
 * @param hasnodata : indicates if the band has nodata value
 * @param nodataval : the nodata value, will be appropriately
 * truncated to fit the pixtype size.
 * @param distancex : the number of pixels around the specified pixel
 * along the X axis
 * @param distancey : the number of pixels around the specified pixel
 * along the Y axis
 * @param mask : the object of mask
 * @param userarg : pointer to any argument that is passed as-is to callback.
 * @param callback : callback function for actual processing of pixel values.
 * @param *rtnraster : return one band raster from iterator process
 *
 * The callback function _must_ have the following signature.
 *
 *    int FNAME(rt_iterator_arg arg, void *userarg, double *value, int *nodata)
 *
 * The callback function _must_ return zero (error) or non-zero (success)
 * indicating whether the function ran successfully.
 * The parameters passed to the callback function are as follows.
 *
 * - rt_iterator_arg arg: struct containing pixel values, NODATA flags and metadata
 * - void *userarg: NULL or calling function provides to rt_raster_iterator() for use by callback function
 * - double *value: value of pixel to be burned by rt_raster_iterator()
 * - int *nodata: flag (0 or 1) indicating that pixel to be burned is NODATA
 *
 * @return ES_NONE on success, ES_ERROR on error
 */
rt_errorstate
rt_raster_iterator(
	rt_iterator itrset, uint16_t itrcount,
	rt_extenttype extenttype, rt_raster customextent,
	rt_pixtype pixtype,
	uint8_t hasnodata, double nodataval,
	uint16_t distancex, uint16_t distancey,
	rt_mask mask,
	void *userarg,
	int (*callback)(
		rt_iterator_arg arg,
		void *userarg,
		double *value,
		int *nodata
	),
	rt_raster *rtnraster
) {
	/* output raster */
	rt_raster rtnrast = NULL;
	/* output raster's band */
	rt_band rtnband = NULL;

	/* working raster */
	rt_raster rast = NULL;

	_rti_iterator_arg _param = NULL;
	int allnull = 0;
	int allempty = 0;
	int aligned = 0;
	double offset[4] = {0.};
	rt_pixel npixels;

	int i = 0;
	int status = 0;
	int inextent = 0;
	int x = 0;
	int y = 0;
	int _x = 0;
	int _y = 0;

	int _width = 0;
	int _height = 0;

	double minval;
	double value;
	int isnodata;
	int nodata;

	RASTER_DEBUG(3, "Starting...");

	assert(itrset != NULL && itrcount > 0);
	assert(rtnraster != NULL);

	/* init rtnraster to NULL */
	*rtnraster = NULL;

	/* check that callback function is not NULL */
	if (callback == NULL) {
		rterror("rt_raster_iterator: Callback function not provided");
		return ES_ERROR;
	}

	/* check that custom extent is provided if extenttype = ET_CUSTOM */
	if (extenttype == ET_CUSTOM && rt_raster_is_empty(customextent)) {
		rterror("rt_raster_iterator: Custom extent cannot be empty if extent type is ET_CUSTOM");
		return ES_ERROR;
	}

	/* check that pixtype != PT_END */
	if (pixtype == PT_END) {
		rterror("rt_raster_iterator: Pixel type cannot be PT_END");
		return ES_ERROR;
	}

	/* initialize _param */
	if ((_param = _rti_iterator_arg_init()) == NULL) {
		rterror("rt_raster_iterator: Could not initialize internal variables");
		return ES_ERROR;
	}

	/* fill _param */
	if (!_rti_iterator_arg_populate(_param, itrset, itrcount, distancex, distancey, &allnull, &allempty)) {
		rterror("rt_raster_iterator: Could not populate for internal variables");
		_rti_iterator_arg_destroy(_param);
		return ES_ERROR;
	}

	/* shortcut if all null, return NULL */
	if (allnull == itrcount) {
		RASTER_DEBUG(3, "all rasters are NULL, returning NULL");

		_rti_iterator_arg_destroy(_param);

		return ES_NONE;
	}
	/* shortcut if all empty, return empty raster */
	else if (allempty == itrcount) {
		RASTER_DEBUG(3, "all rasters are empty, returning empty raster");

		_rti_iterator_arg_destroy(_param);

		rtnrast = rt_raster_new(0, 0);
		if (rtnrast == NULL) {
			rterror("rt_raster_iterator: Could not create empty raster");
			return ES_ERROR;
		}
		rt_raster_set_scale(rtnrast, 0, 0);

		*rtnraster = rtnrast;
		return ES_NONE;
	}

	/* check that all rasters are aligned */
	RASTER_DEBUG(3, "checking alignment of all rasters");
	rast = NULL;

	/* find raster to use as reference */
	/* use custom if provided */
	if (extenttype == ET_CUSTOM) {
		RASTER_DEBUG(4, "using custom extent as reference raster");
		rast = customextent;
	}
	/* use first valid one in _param->raster */
	else {
		for (i = 0; i < itrcount; i++) {
			if (!_param->isempty[i]) {
				RASTER_DEBUGF(4, "using raster at index %d as reference raster", i);
				rast = _param->raster[i];
				break;
			}
		}
	}

	/* no rasters found, SHOULD NEVER BE HERE! */
	if (rast == NULL) {
		rterror("rt_raster_iterator: Could not find reference raster to use for alignment tests");

		_rti_iterator_arg_destroy(_param);

		return ES_ERROR;
	}

	do {
		aligned = 1;

		/* check custom first if set. also skip if rasters are the same */
		if (extenttype == ET_CUSTOM && rast != customextent) {
			if (rt_raster_same_alignment(rast, customextent, &aligned, NULL) != ES_NONE) {
				rterror("rt_raster_iterator: Could not test for alignment between reference raster and custom extent");

				_rti_iterator_arg_destroy(_param);

				return ES_ERROR;
			}

			RASTER_DEBUGF(5, "custom extent alignment: %d", aligned);
			if (!aligned)
				break;
		}

		for (i = 0; i < itrcount; i++) {
			/* skip NULL rasters and if rasters are the same */
			if (_param->isempty[i] || rast == _param->raster[i])
				continue;

			if (rt_raster_same_alignment(rast, _param->raster[i], &aligned, NULL) != ES_NONE) {
				rterror("rt_raster_iterator: Could not test for alignment between reference raster and raster %d", i);

				_rti_iterator_arg_destroy(_param);

				return ES_ERROR;
			}
			RASTER_DEBUGF(5, "raster at index %d alignment: %d", i, aligned);

			/* abort checking since a raster isn't aligned */
			if (!aligned)
				break;
		}
	}
	while (0);

	/* not aligned, error */
	if (!aligned) {
		rterror("rt_raster_iterator: The set of rasters provided (custom extent included, if appropriate) do not have the same alignment");

		_rti_iterator_arg_destroy(_param);

		return ES_ERROR;
	}

	/* use extenttype to build output raster (no bands though) */
	i = -1;
	switch (extenttype) {
		case ET_INTERSECTION:
		case ET_UNION:
			/* make copy of first "real" raster */
			rtnrast = rtalloc(sizeof(struct rt_raster_t));
			if (rtnrast == NULL) {
				rterror("rt_raster_iterator: Could not allocate memory for output raster");

				_rti_iterator_arg_destroy(_param);

				return ES_ERROR;
			}

			for (i = 0; i < itrcount; i++) {
				if (!_param->isempty[i]) {
					memcpy(rtnrast, _param->raster[i], sizeof(struct rt_raster_serialized_t));
					break;
				}
			}
			rtnrast->numBands = 0;
			rtnrast->bands = NULL;

			/* get extent of output raster */
			rast = NULL;
			for (i = i + 1; i < itrcount; i++) {
				if (_param->isempty[i])
					continue;

				status = rt_raster_from_two_rasters(rtnrast, _param->raster[i], extenttype, &rast, NULL);
				rtdealloc(rtnrast);

				if (rast == NULL || status != ES_NONE) {
					rterror("rt_raster_iterator: Could not compute %s extent of rasters",
						extenttype == ET_UNION ? "union" : "intersection"
					);

					_rti_iterator_arg_destroy(_param);

					return ES_ERROR;
				}
				else if (rt_raster_is_empty(rast)) {
					rtinfo("rt_raster_iterator: Computed raster for %s extent is empty",
						extenttype == ET_UNION ? "union" : "intersection"
					);

					_rti_iterator_arg_destroy(_param);

					*rtnraster = rast;
					return ES_NONE;
				}

				rtnrast = rast;
				rast = NULL;
			}

			break;
		/*
			first, second and last have similar checks
			and continue into custom
		*/
		case ET_FIRST:
			i = 0;
		case ET_SECOND:
			if (i < 0) {
				if (itrcount < 2)
					i = 0;
				else
					i = 1;
			}
		case ET_LAST:
			if (i < 0) i = itrcount - 1;
			
			/* input raster is null, return NULL */
			if (_param->raster[i] == NULL) {
				RASTER_DEBUGF(3, "returning NULL as %s raster is NULL and extent type is ET_%s",
					(i == 0 ? "first" : (i == 1 ? "second" : "last")),
					(i == 0 ? "FIRST" : (i == 1 ? "SECOND" : "LAST"))
				);

				_rti_iterator_arg_destroy(_param);

				return ES_NONE;
			}
			/* input raster is empty, return empty raster */
			else if (_param->isempty[i]) {
				RASTER_DEBUGF(3, "returning empty raster as %s raster is empty and extent type is ET_%s",
					(i == 0 ? "first" : (i == 1 ? "second" : "last")),
					(i == 0 ? "FIRST" : (i == 1 ? "SECOND" : "LAST"))
				);

				_rti_iterator_arg_destroy(_param);

				rtnrast = rt_raster_new(0, 0);
				if (rtnrast == NULL) {
					rterror("rt_raster_iterator: Could not create empty raster");
					return ES_ERROR;
				}
				rt_raster_set_scale(rtnrast, 0, 0);

				*rtnraster = rtnrast;
				return ES_NONE;
			}
		/* copy the custom extent raster */
		case ET_CUSTOM:
			rtnrast = rtalloc(sizeof(struct rt_raster_t));
			if (rtnrast == NULL) {
				rterror("rt_raster_iterator: Could not allocate memory for output raster");

				_rti_iterator_arg_destroy(_param);

				return ES_ERROR;
			}

			switch (extenttype) {
				case ET_CUSTOM:
					memcpy(rtnrast, customextent, sizeof(struct rt_raster_serialized_t));
					break;
				/* first, second, last */
				default:
					memcpy(rtnrast, _param->raster[i], sizeof(struct rt_raster_serialized_t));
					break;
			}
			rtnrast->numBands = 0;
			rtnrast->bands = NULL;
			break;
	}

	_width = rt_raster_get_width(rtnrast);
	_height = rt_raster_get_height(rtnrast);

	RASTER_DEBUGF(4, "rtnrast (width, height, ulx, uly, scalex, scaley, skewx, skewy, srid) = (%d, %d, %f, %f, %f, %f, %f, %f, %d)",
		_width,
		_height,
		rt_raster_get_x_offset(rtnrast),
		rt_raster_get_y_offset(rtnrast),
		rt_raster_get_x_scale(rtnrast),
		rt_raster_get_y_scale(rtnrast),
		rt_raster_get_x_skew(rtnrast),
		rt_raster_get_y_skew(rtnrast),
		rt_raster_get_srid(rtnrast)
	);

	/* init values and NODATA for use with empty rasters */
	if (!_rti_iterator_arg_empty_init(_param)) {
		rterror("rt_raster_iterator: Could not initialize empty values and NODATA");

		_rti_iterator_arg_destroy(_param);
		rt_raster_destroy(rtnrast);
		
		return ES_ERROR;
	}

	/* create output band */
	if (rt_raster_generate_new_band(
		rtnrast,
		pixtype,
		nodataval,
		hasnodata, nodataval,
		0
	) < 0) {
		rterror("rt_raster_iterator: Could not add new band to output raster");

		_rti_iterator_arg_destroy(_param);
		rt_raster_destroy(rtnrast);

		return ES_ERROR;
	}

	/* get output band */
	rtnband = rt_raster_get_band(rtnrast, 0);
	if (rtnband == NULL) {
		rterror("rt_raster_iterator: Could not get new band from output raster");

		_rti_iterator_arg_destroy(_param);
		rt_raster_destroy(rtnrast);

		return ES_ERROR;
	}

	/* output band's minimum value */
	minval = rt_band_get_min_value(rtnband);

	/* initialize argument for callback function */
	if (!_rti_iterator_arg_callback_init(_param)) {
		rterror("rt_raster_iterator: Could not initialize callback function argument");

		_rti_iterator_arg_destroy(_param);
		rt_band_destroy(rtnband);
		rt_raster_destroy(rtnrast);

		return ES_ERROR;
	}

	/* fill _param->offset */
	for (i = 0; i < itrcount; i++) {
		if (_param->isempty[i])
			continue;

		status = rt_raster_from_two_rasters(rtnrast, _param->raster[i], ET_FIRST, &rast, offset);
		rtdealloc(rast);
		if (status != ES_NONE) {
			rterror("rt_raster_iterator: Could not compute raster offsets");

			_rti_iterator_arg_destroy(_param);
			rt_band_destroy(rtnband);
			rt_raster_destroy(rtnrast);

			return ES_ERROR;
		}

		_param->offset[i][0] = offset[2];
		_param->offset[i][1] = offset[3];
		RASTER_DEBUGF(4, "rast %d offset: %f %f", i, offset[2], offset[3]);
	}

	/* loop over each pixel (POI) of output raster */
	/* _x,_y are for output raster */
	/* x,y are for input raster */
	for (_y = 0; _y < _height; _y++) {
		for (_x = 0; _x < _width; _x++) {
			RASTER_DEBUGF(4, "iterating output pixel (x, y) = (%d, %d)", _x, _y);
			_param->arg->dst_pixel[0] = _x;
			_param->arg->dst_pixel[1] = _y;

			/* loop through each input raster */
			for (i = 0; i < itrcount; i++) {
				RASTER_DEBUGF(4, "raster %d", i);

				/*
					empty raster
					OR band does not exist and flag set to use NODATA
					OR band is NODATA
				*/
				if (
					_param->isempty[i] ||
					(_param->band.rtband[i] == NULL && itrset[i].nbnodata) ||
					_param->band.isnodata[i]
				) {
					RASTER_DEBUG(4, "empty raster, band does not exist or band is NODATA. using empty values and NODATA");
					
					x = _x;
					y = _y;

					_param->arg->values[i] = _param->empty.values;
					_param->arg->nodata[i] = _param->empty.nodata;

					continue;
				}

				/* input raster's X,Y */
				x = _x - (int) _param->offset[i][0];
				y = _y - (int) _param->offset[i][1];
				RASTER_DEBUGF(4, "source pixel (x, y) = (%d, %d)", x, y);

				_param->arg->src_pixel[i][0] = x;
				_param->arg->src_pixel[i][1] = y;

				/* neighborhood */
				npixels = NULL;
				status = 0;
				if (distancex > 0 && distancey > 0) {
					RASTER_DEBUG(4, "getting neighborhood");

					status = rt_band_get_nearest_pixel(
						_param->band.rtband[i],
						x, y,
						distancex, distancey,
						1,
						&npixels
					);
					if (status < 0) {
						rterror("rt_raster_iterator: Could not get pixel neighborhood");

						_rti_iterator_arg_destroy(_param);
						rt_band_destroy(rtnband);
						rt_raster_destroy(rtnrast);

						return ES_ERROR;
					}
				}

				/* get value of POI */
				/* get pixel's value */
				if (
					(x >= 0 && x < _param->width[i]) &&
					(y >= 0 && y < _param->height[i])
				) {
					RASTER_DEBUG(4, "getting value of POI");
					if (rt_band_get_pixel(
						_param->band.rtband[i],
						x, y,
						&value,
						&isnodata
					) != ES_NONE) {
						rterror("rt_raster_iterator: Could not get the pixel value of band");

						_rti_iterator_arg_destroy(_param);
						rt_band_destroy(rtnband);
						rt_raster_destroy(rtnrast);

						return ES_ERROR;
					}
					inextent = 1;
				}
				/* outside band extent, set to NODATA */
				else {
					RASTER_DEBUG(4, "Outside band extent, setting value to NODATA");
					/* has NODATA, use NODATA */
					if (_param->band.hasnodata[i])
						value = _param->band.nodataval[i];
					/* no NODATA, use min possible value */
					else
						value = _param->band.minval[i];

					inextent = 0;
					isnodata = 1;
				}

				/* add pixel to neighborhood */
				status++;
				if (status > 1)
					npixels = (rt_pixel) rtrealloc(npixels, sizeof(struct rt_pixel_t) * status);
				else
					npixels = (rt_pixel) rtalloc(sizeof(struct rt_pixel_t));

				if (npixels == NULL) {
					rterror("rt_raster_iterator: Could not reallocate memory for neighborhood");

					_rti_iterator_arg_destroy(_param);
					rt_band_destroy(rtnband);
					rt_raster_destroy(rtnrast);

					return ES_ERROR;
				}

				npixels[status - 1].x = x;
				npixels[status - 1].y = y;
				npixels[status - 1].nodata = 1;
				npixels[status - 1].value = value;

				/* set nodata flag */
				if ((!_param->band.hasnodata[i] && inextent) || !isnodata) {
					npixels[status - 1].nodata = 0;
				}
				RASTER_DEBUGF(4, "value, nodata: %f, %d", value, npixels[status - 1].nodata);

				/* convert set of rt_pixel to 2D array */
				status = rt_pixel_set_to_array(
					npixels, status,mask,
					x, y,
					distancex, distancey,
					&(_param->arg->values[i]),
					&(_param->arg->nodata[i]),
					NULL, NULL
				);
				rtdealloc(npixels);
				if (status != ES_NONE) {
					rterror("rt_raster_iterator: Could not create 2D array of neighborhood");

					_rti_iterator_arg_destroy(_param);
					rt_band_destroy(rtnband);
					rt_raster_destroy(rtnrast);

					return ES_ERROR;
				}
			}
	
			/* callback */
			RASTER_DEBUG(4, "calling callback function");
			value = 0;
			nodata = 0;
			status = callback(_param->arg, userarg, &value, &nodata);

			/* free memory from callback */
			_rti_iterator_arg_callback_clean(_param);

			/* handle callback status */
			if (status == 0) {
				rterror("rt_raster_iterator: Callback function returned an error");

				_rti_iterator_arg_destroy(_param);
				rt_band_destroy(rtnband);
				rt_raster_destroy(rtnrast);

				return ES_ERROR;
			}

			/* burn value to pixel */
			status = 0;
			if (!nodata) {
				status = rt_band_set_pixel(rtnband, _x, _y, value, NULL);
				RASTER_DEBUGF(4, "burning pixel (%d, %d) with value: %f", _x, _y, value);
			}
			else if (!hasnodata) {
				status = rt_band_set_pixel(rtnband, _x, _y, minval, NULL);
				RASTER_DEBUGF(4, "burning pixel (%d, %d) with minval: %f", _x, _y, minval);
			}
			else {
				RASTER_DEBUGF(4, "NOT burning pixel (%d, %d)", _x, _y);
			}
			if (status != ES_NONE) {
				rterror("rt_raster_iterator: Could not set pixel value");

				_rti_iterator_arg_destroy(_param);
				rt_band_destroy(rtnband);
				rt_raster_destroy(rtnrast);

				return ES_ERROR;
			}
		}
	}

	/* lots of cleanup */
	_rti_iterator_arg_destroy(_param);

	*rtnraster = rtnrast;
	return ES_NONE;
}
Datum RASTER_dwithin(PG_FUNCTION_ARGS)
{
	const int set_count = 2;
	rt_pgraster *pgrast[2];
	int pgrastpos[2] = {-1, -1};
	rt_raster rast[2] = {NULL};
	uint32_t bandindex[2] = {0};
	uint32_t hasbandindex[2] = {0};
	double distance = 0;

	uint32_t i;
	uint32_t j;
	uint32_t k;
	uint32_t numBands;
	int rtn;
	int result;

	for (i = 0, j = 0; i < set_count; i++) {
		/* pgrast is null, return null */
		if (PG_ARGISNULL(j)) {
			for (k = 0; k < i; k++) {
				rt_raster_destroy(rast[k]);
				PG_FREE_IF_COPY(pgrast[k], pgrastpos[k]);
			}
			PG_RETURN_NULL();
		}
		pgrast[i] = (rt_pgraster *) PG_DETOAST_DATUM(PG_GETARG_DATUM(j));
		pgrastpos[i] = j;
		j++;

		/* raster */
		rast[i] = rt_raster_deserialize(pgrast[i], FALSE);
		if (!rast[i]) {
			for (k = 0; k <= i; k++) {
				if (k < i)
					rt_raster_destroy(rast[k]);
				PG_FREE_IF_COPY(pgrast[k], pgrastpos[k]);
			}
			elog(ERROR, "RASTER_dwithin: Could not deserialize the %s raster", i < 1 ? "first" : "second");
			PG_RETURN_NULL();
		}

		/* numbands */
		numBands = rt_raster_get_num_bands(rast[i]);
		if (numBands < 1) {
			elog(NOTICE, "The %s raster provided has no bands", i < 1 ? "first" : "second");
			if (i > 0) i++;
			for (k = 0; k < i; k++) {
				rt_raster_destroy(rast[k]);
				PG_FREE_IF_COPY(pgrast[k], pgrastpos[k]);
			}
			PG_RETURN_NULL();
		}

		/* band index */
		if (!PG_ARGISNULL(j)) {
			bandindex[i] = PG_GETARG_INT32(j);
			if (bandindex[i] < 1 || bandindex[i] > numBands) {
				elog(NOTICE, "Invalid band index (must use 1-based) for the %s raster. Returning NULL", i < 1 ? "first" : "second");
				if (i > 0) i++;
				for (k = 0; k < i; k++) {
					rt_raster_destroy(rast[k]);
					PG_FREE_IF_COPY(pgrast[k], pgrastpos[k]);
				}
				PG_RETURN_NULL();
			}
			hasbandindex[i] = 1;
		}
		else
			hasbandindex[i] = 0;
		POSTGIS_RT_DEBUGF(4, "hasbandindex[%d] = %d", i, hasbandindex[i]);
		POSTGIS_RT_DEBUGF(4, "bandindex[%d] = %d", i, bandindex[i]);
		j++;
	}

	/* distance */
	if (PG_ARGISNULL(4)) {
		elog(NOTICE, "Distance cannot be NULL.  Returning NULL");
		for (k = 0; k < set_count; k++) {
			rt_raster_destroy(rast[k]);
			PG_FREE_IF_COPY(pgrast[k], pgrastpos[k]);
		}
		PG_RETURN_NULL();
	}

	distance = PG_GETARG_FLOAT8(4);
	if (distance < 0) {
		elog(NOTICE, "Distance cannot be less than zero.  Returning NULL");
		for (k = 0; k < set_count; k++) {
			rt_raster_destroy(rast[k]);
			PG_FREE_IF_COPY(pgrast[k], pgrastpos[k]);
		}
		PG_RETURN_NULL();
	}

	/* hasbandindex must be balanced */
	if (
		(hasbandindex[0] && !hasbandindex[1]) ||
		(!hasbandindex[0] && hasbandindex[1])
	) {
		elog(NOTICE, "Missing band index.  Band indices must be provided for both rasters if any one is provided");
		for (k = 0; k < set_count; k++) {
			rt_raster_destroy(rast[k]);
			PG_FREE_IF_COPY(pgrast[k], pgrastpos[k]);
		}
		PG_RETURN_NULL();
	}

	/* SRID must match */
	if (rt_raster_get_srid(rast[0]) != rt_raster_get_srid(rast[1])) {
		for (k = 0; k < set_count; k++) {
			rt_raster_destroy(rast[k]);
			PG_FREE_IF_COPY(pgrast[k], pgrastpos[k]);
		}
		elog(ERROR, "The two rasters provided have different SRIDs");
		PG_RETURN_NULL();
	}

	rtn = rt_raster_within_distance(
		rast[0], (hasbandindex[0] ? bandindex[0] - 1 : -1),
		rast[1], (hasbandindex[1] ? bandindex[1] - 1 : -1),
		distance,
		&result
	);
	for (k = 0; k < set_count; k++) {
		rt_raster_destroy(rast[k]);
		PG_FREE_IF_COPY(pgrast[k], pgrastpos[k]);
	}

	if (rtn != ES_NONE) {
		elog(ERROR, "RASTER_dwithin: Could not test that the two rasters are within the specified distance of each other");
		PG_RETURN_NULL();
	}

	PG_RETURN_BOOL(result);
}