/*!
* \brief boxaPermutePseudorandom()
*
* \param[in] boxas input boxa
* \return boxad with boxes permuted, or NULL on error
*
* <pre>
* Notes:
* (1) This does a pseudorandom in-place permutation of the boxes.
* (2) The result is guaranteed not to have any boxes in their
* original position, but it is not very random. If you
* need randomness, use boxaPermuteRandom().
* </pre>
*/
BOXA *
boxaPermutePseudorandom(BOXA *boxas)
{
l_int32 n;
NUMA *na;
BOXA *boxad;
PROCNAME("boxaPermutePseudorandom");
if (!boxas)
return (BOXA *)ERROR_PTR("boxa not defined", procName, NULL);
n = boxaGetCount(boxas);
na = numaPseudorandomSequence(n, 0);
boxad = boxaSortByIndex(boxas, na);
numaDestroy(&na);
return boxad;
}
/*!
* boxaBinSort()
*
* Input: boxa
* sorttype (L_SORT_BY_X, L_SORT_BY_Y, L_SORT_BY_WIDTH,
* L_SORT_BY_HEIGHT, L_SORT_BY_PERIMETER)
* sortorder (L_SORT_INCREASING, L_SORT_DECREASING)
* &naindex (<optional return> index of sorted order into
* original array)
* Return: boxad (sorted version of boxas), or null on error
*
* Notes:
* (1) For a large number of boxes (say, greater than 1000), this
* O(n) binsort is much faster than the O(nlogn) shellsort.
* For 5000 components, this is over 20x faster than boxaSort().
* (2) Consequently, boxaSort() calls this function if it will
* likely go much faster.
*/
BOXA *
boxaBinSort(BOXA *boxas,
l_int32 sorttype,
l_int32 sortorder,
NUMA **pnaindex)
{
l_int32 i, n, x, y, w, h;
BOXA *boxad;
NUMA *na, *naindex;
PROCNAME("boxaBinSort");
if (pnaindex) *pnaindex = NULL;
if (!boxas)
return (BOXA *)ERROR_PTR("boxas not defined", procName, NULL);
if (sorttype != L_SORT_BY_X && sorttype != L_SORT_BY_Y &&
sorttype != L_SORT_BY_WIDTH && sorttype != L_SORT_BY_HEIGHT &&
sorttype != L_SORT_BY_PERIMETER)
return (BOXA *)ERROR_PTR("invalid sort type", procName, NULL);
if (sortorder != L_SORT_INCREASING && sortorder != L_SORT_DECREASING)
return (BOXA *)ERROR_PTR("invalid sort order", procName, NULL);
/* Generate Numa of appropriate box dimensions */
n = boxaGetCount(boxas);
if ((na = numaCreate(n)) == NULL)
return (BOXA *)ERROR_PTR("na not made", procName, NULL);
for (i = 0; i < n; i++) {
boxaGetBoxGeometry(boxas, i, &x, &y, &w, &h);
switch (sorttype)
{
case L_SORT_BY_X:
numaAddNumber(na, x);
break;
case L_SORT_BY_Y:
numaAddNumber(na, y);
break;
case L_SORT_BY_WIDTH:
numaAddNumber(na, w);
break;
case L_SORT_BY_HEIGHT:
numaAddNumber(na, h);
break;
case L_SORT_BY_PERIMETER:
numaAddNumber(na, w + h);
break;
default:
L_WARNING("invalid sort type", procName);
}
}
/* Get the sort index for data array */
if ((naindex = numaGetBinSortIndex(na, sortorder)) == NULL)
return (BOXA *)ERROR_PTR("naindex not made", procName, NULL);
/* Build up sorted boxa using the sort index */
boxad = boxaSortByIndex(boxas, naindex);
if (pnaindex)
*pnaindex = naindex;
else
numaDestroy(&naindex);
numaDestroy(&na);
return boxad;
}
/*!
* boxaSort()
*
* Input: boxa
* sorttype (L_SORT_BY_X, L_SORT_BY_Y, L_SORT_BY_WIDTH,
* L_SORT_BY_HEIGHT, L_SORT_BY_MIN_DIMENSION,
* L_SORT_BY_MAX_DIMENSION, L_SORT_BY_PERIMETER,
* L_SORT_BY_AREA, L_SORT_BY_ASPECT_RATIO)
* sortorder (L_SORT_INCREASING, L_SORT_DECREASING)
* &naindex (<optional return> index of sorted order into
* original array)
* Return: boxad (sorted version of boxas), or null on error
*/
BOXA *
boxaSort(BOXA *boxas,
l_int32 sorttype,
l_int32 sortorder,
NUMA **pnaindex)
{
l_int32 i, n, x, y, w, h, size;
BOXA *boxad;
NUMA *na, *naindex;
PROCNAME("boxaSort");
if (pnaindex) *pnaindex = NULL;
if (!boxas)
return (BOXA *)ERROR_PTR("boxas not defined", procName, NULL);
if (sorttype != L_SORT_BY_X && sorttype != L_SORT_BY_Y &&
sorttype != L_SORT_BY_WIDTH && sorttype != L_SORT_BY_HEIGHT &&
sorttype != L_SORT_BY_MIN_DIMENSION &&
sorttype != L_SORT_BY_MAX_DIMENSION &&
sorttype != L_SORT_BY_PERIMETER &&
sorttype != L_SORT_BY_AREA &&
sorttype != L_SORT_BY_ASPECT_RATIO)
return (BOXA *)ERROR_PTR("invalid sort type", procName, NULL);
if (sortorder != L_SORT_INCREASING && sortorder != L_SORT_DECREASING)
return (BOXA *)ERROR_PTR("invalid sort order", procName, NULL);
/* Use O(n) binsort if possible */
n = boxaGetCount(boxas);
if (n > MIN_COMPS_FOR_BIN_SORT &&
((sorttype == L_SORT_BY_X) || (sorttype == L_SORT_BY_Y) ||
(sorttype == L_SORT_BY_WIDTH) || (sorttype == L_SORT_BY_HEIGHT) ||
(sorttype == L_SORT_BY_PERIMETER)))
return boxaBinSort(boxas, sorttype, sortorder, pnaindex);
/* Build up numa of specific data */
if ((na = numaCreate(n)) == NULL)
return (BOXA *)ERROR_PTR("na not made", procName, NULL);
for (i = 0; i < n; i++) {
boxaGetBoxGeometry(boxas, i, &x, &y, &w, &h);
switch (sorttype)
{
case L_SORT_BY_X:
numaAddNumber(na, x);
break;
case L_SORT_BY_Y:
numaAddNumber(na, y);
break;
case L_SORT_BY_WIDTH:
numaAddNumber(na, w);
break;
case L_SORT_BY_HEIGHT:
numaAddNumber(na, h);
break;
case L_SORT_BY_MIN_DIMENSION:
size = L_MIN(w, h);
numaAddNumber(na, size);
break;
case L_SORT_BY_MAX_DIMENSION:
size = L_MAX(w, h);
numaAddNumber(na, size);
break;
case L_SORT_BY_PERIMETER:
size = w + h;
numaAddNumber(na, size);
break;
case L_SORT_BY_AREA:
size = w * h;
numaAddNumber(na, size);
break;
case L_SORT_BY_ASPECT_RATIO:
numaAddNumber(na, (l_float32)w / (l_float32)h);
break;
default:
L_WARNING("invalid sort type", procName);
}
}
/* Get the sort index for data array */
if ((naindex = numaGetSortIndex(na, sortorder)) == NULL)
return (BOXA *)ERROR_PTR("naindex not made", procName, NULL);
/* Build up sorted boxa using sort index */
boxad = boxaSortByIndex(boxas, naindex);
if (pnaindex)
*pnaindex = naindex;
else
numaDestroy(&naindex);
numaDestroy(&na);
return boxad;
}
