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Leptonica 1.68
C Image Processing Library
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Leptonica 1.68
C Image Processing Library
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Quadtree creation and statistics. More...
Go to the source code of this file.
Defines | |
| #define | DEBUG_BOXES 0 |
Functions | |
| l_int32 | pixQuadtreeMean (PIX *pixs, l_int32 nlevels, PIX *pix_ma, FPIXA **pfpixa) |
| l_int32 | pixQuadtreeVariance (PIX *pixs, l_int32 nlevels, PIX *pix_ma, DPIX *dpix_msa, FPIXA **pfpixa_v, FPIXA **pfpixa_rv) |
| l_int32 | pixMeanInRectangle (PIX *pixs, BOX *box, PIX *pixma, l_float32 *pval) |
| l_int32 | pixVarianceInRectangle (PIX *pixs, BOX *box, PIX *pix_ma, DPIX *dpix_msa, l_float32 *pvar, l_float32 *prvar) |
| BOXAA * | boxaaQuadtreeRegions (l_int32 w, l_int32 h, l_int32 nlevels) |
| l_int32 | quadtreeGetParent (FPIXA *fpixa, l_int32 level, l_int32 x, l_int32 y, l_float32 *pval) |
| l_int32 | quadtreeGetChildren (FPIXA *fpixa, l_int32 level, l_int32 x, l_int32 y, l_float32 *pval00, l_float32 *pval10, l_float32 *pval01, l_float32 *pval11) |
| l_int32 | quadtreeMaxLevels (l_int32 w, l_int32 h) |
| PIX * | fpixaDisplayQuadtree (FPIXA *fpixa, l_int32 factor) |
Quadtree creation and statistics.
Top level quadtree linear statistics
l_int32 pixQuadtreeMean()
l_int32 pixQuadtreeVariance()
Statistics in an arbitrary rectangle
l_int32 pixMeanInRectangle()
l_int32 pixVarianceInRectangle()
Quadtree regions
BOXAA *boxaaQuadtreeRegions()
Quadtree access
l_int32 quadtreeGetParent()
l_int32 quadtreeGetChildren()
l_int32 quadtreeMaxLevels()
Display quadtree
PIX *fpixaDisplayQuadtree()
There are many other statistical quantities that can be computed
in a quadtree, such as rank values, and these can be added as
the need arises.
Similar results that can approximate a single level of the quadtree
can be generated by pixGetAverageTiled(). There we specify the
tile size over which the mean, mean square, and root variance
are generated; the results are saved in a (reduced size) pix.
Because the tile dimensions are integers, it is usually not possible
to obtain tilings that are a power of 2, as required for quadtrees.
Definition in file quadtree.c.
| #define DEBUG_BOXES 0 |
Definition at line 55 of file quadtree.c.
Input: pixs (8 bpp, no colormap) nlevels (in quadtree; max allowed depends on image size) *pix_ma (input mean accumulator; can be null) *pfpixa (<return> mean values in quadtree) Return: 0 if OK, 1 on error
Notes: (1) The returned fpixa has of fpix, each containing the mean values at its level. Level 0 has a single value; level 1 has 4 values; level 2 has 16; etc.
Definition at line 77 of file quadtree.c.
References boxaaDestroy(), boxaaGetBoxa(), boxaaQuadtreeRegions(), boxaDestroy(), boxaGetBox(), boxaGetCount(), boxDestroy(), ERROR_INT, fpixaAddFPix(), fpixaCreate(), fpixCreate(), fpixSetPixel(), L_CLONE, L_INSERT, nlevels, NULL, pixBlockconvAccum(), pixClone(), pixDestroy(), pixGetDepth(), pixGetDimensions(), pixMeanInRectangle(), PROCNAME, quadtreeMaxLevels(), and size.
Referenced by main().
| l_int32 pixQuadtreeVariance | ( | PIX * | pixs, |
| l_int32 | nlevels, | ||
| PIX * | pix_ma, | ||
| DPIX * | dpix_msa, | ||
| FPIXA ** | pfpixa_v, | ||
| FPIXA ** | pfpixa_rv | ||
| ) |
Input: pixs (8 bpp, no colormap) nlevels (in quadtree) *pix_ma (input mean accumulator; can be null) *dpix_msa (input mean square accumulator; can be null) *pfpixa_v (<optional return>=""> variance values in quadtree) *pfpixa_rv (<optional return>=""> root variance values in quadtree) Return: 0 if OK, 1 on error
Notes: (1) The returned fpixav and fpixarv have of fpix, each containing at the respective levels the variance and root variance values.
Definition at line 152 of file quadtree.c.
References boxaaDestroy(), boxaaGetBoxa(), boxaaQuadtreeRegions(), boxaDestroy(), boxaGetBox(), boxaGetCount(), boxDestroy(), dpixClone(), dpixDestroy(), ERROR_INT, fpixaAddFPix(), fpixaCreate(), fpixCreate(), fpixSetPixel(), L_CLONE, L_INSERT, nlevels, NULL, pixBlockconvAccum(), pixClone(), pixDestroy(), pixGetDepth(), pixGetDimensions(), pixMeanSquareAccum(), pixVarianceInRectangle(), PROCNAME, quadtreeMaxLevels(), and size.
Referenced by main().
Input: pix (8 bpp) box (region to compute mean value) pixma (mean accumulator) &val (<return> mean value Return: 0 if OK, 1 on error
Notes: (1) This function is intended to be used for many rectangles on the same image. It can find the mean within a rectangle in O(1), independent of the size of the rectangle.
Definition at line 244 of file quadtree.c.
References boxClipToRectangle(), boxDestroy(), boxGetGeometry(), ERROR_INT, NULL, pixGetDepth(), pixGetDimensions(), pixGetPixel(), and PROCNAME.
Referenced by pixQuadtreeMean().
| l_int32 pixVarianceInRectangle | ( | PIX * | pixs, |
| BOX * | box, | ||
| PIX * | pix_ma, | ||
| DPIX * | dpix_msa, | ||
| l_float32 * | pvar, | ||
| l_float32 * | prvar | ||
| ) |
Input: pix (8 bpp) box (region to compute variance and/or root variance) pix_ma (mean accumulator) dpix_msa (mean square accumulator) &var (<optional return>=""> variance) &rvar (<optional return>=""> root variance) Return: 0 if OK, 1 on error
Notes: (1) This function is intended to be used for many rectangles on the same image. It can find the variance and/or the square root of the variance within a rectangle in O(1), independent of the size of the rectangle.
Definition at line 321 of file quadtree.c.
References boxClipToRectangle(), boxDestroy(), boxGetGeometry(), dpixGetPixel(), ERROR_INT, NULL, pixGetDepth(), pixGetDimensions(), pixGetPixel(), and PROCNAME.
Referenced by pixQuadtreeVariance().
Input: w, h (of pix that is being quadtree-ized) nlevels (in quadtree) Return: baa (for quadtree regions at each level), or null on error
Notes: (1) The returned boxaa has of boxa, each containing the set of rectangles at that level. The rectangle at level 0 is the entire region; at level 1 the region is divided into 4 rectangles, and at level n there are n^4 rectangles. (2) At each level, the rectangles in the boxa are in "raster" order, with LR (fast scan) and TB (slow scan).
Definition at line 430 of file quadtree.c.
References boxaaAddBoxa(), boxaaCreate(), boxaAddBox(), boxaCreate(), boxCreate(), CALLOC, ERROR_PTR, FREE, L_INSERT, nlevels, NULL, and PROCNAME.
Referenced by main(), pixQuadtreeMean(), and pixQuadtreeVariance().
Input: fpixa (mean, variance or root variance) level, x, y (of current pixel) &val (<return> parent pixel value), or 0.0 on error. Return: 0 if OK, 1 on error
Notes: (1) Check return value for error. On error, val is returned as 0.0. (2) The parent is located at: level - 1 (x/2, y/2)
Definition at line 509 of file quadtree.c.
References ERROR_INT, fpixaGetCount(), fpixaGetPixel(), and PROCNAME.
Referenced by main().
| l_int32 quadtreeGetChildren | ( | FPIXA * | fpixa, |
| l_int32 | level, | ||
| l_int32 | x, | ||
| l_int32 | y, | ||
| l_float32 * | pval00, | ||
| l_float32 * | pval10, | ||
| l_float32 * | pval01, | ||
| l_float32 * | pval11 | ||
| ) |
Input: fpixa (mean, variance or root variance) level, x, y (of current pixel) &val00, val01, val10, val11 (<return> child pixel values) Return: 0 if OK, 1 on error
Notes: (1) Check return value for error. On error, all return vals are 0.0. (2) The returned child pixels are located at: level + 1 (2x, 2y), (2x+1, 2y), (2x, 2y+1), (2x+1, 2y+1)
Definition at line 549 of file quadtree.c.
References ERROR_INT, fpixaGetCount(), fpixaGetPixel(), and PROCNAME.
Referenced by main().
Input: w, h (of image) Return: maxlevels (maximum number of levels allowed), or -1 on error
Notes: (1) The criterion for maxlevels is that the subdivision not go down below the single pixel level. The 1.5 factor is intended to keep any rectangle from accidentally having zero dimension due to integer truncation.
Definition at line 593 of file quadtree.c.
References L_MIN.
Referenced by pixQuadtreeMean(), and pixQuadtreeVariance().
Input: fpixa (mean, variance or root variance) factor (replication factor at lowest level) Return: pixd (8 bpp, mosaic of quadtree images), or null on error
Notes: (1) The mean and root variance fall naturally in the 8 bpp range, but the variance is typically outside the range. This function displays 8 bpp pix clipped to 255, so the image pixels will mostly be 255 (white).
Definition at line 625 of file quadtree.c.
References bmfCreate(), bmfDestroy(), buf, ERROR_PTR, fpixaGetCount(), fpixaGetFPix(), fpixConvertToPix(), fpixDestroy(), L_ADD_BELOW, L_CLIP_TO_ZERO, L_CLONE, L_INSERT, nlevels, NULL, pixaAddPix(), pixaCreate(), pixAddSingleTextblock(), pixaDestroy(), pixaDisplayTiledInRows(), pixConvertTo32(), pixDestroy(), pixExpandReplicate(), pixGetWidth(), and PROCNAME.
Referenced by main().
1.7.3