Leptonica 1.54
|
#define DEBUG 0 |
l_int32 nextOnPixelInRaster | ( | PIX * | pixs, |
l_int32 | xstart, | ||
l_int32 | ystart, | ||
l_int32 * | px, | ||
l_int32 * | py | ||
) |
Input: pixs (1 bpp) xstart, ystart (starting point for search) &x, &y (<return> coord value of next ON pixel) Return: 1 if a pixel is found; 0 otherwise or on error
l_int32 nextOnPixelInRasterLow | ( | l_uint32 * | data, |
l_int32 | w, | ||
l_int32 | h, | ||
l_int32 | wpl, | ||
l_int32 | xstart, | ||
l_int32 | ystart, | ||
l_int32 * | px, | ||
l_int32 * | py | ||
) |
Input: pixs (1 bpp) &pixa (<optional return>=""> pixa of each c.c.) connectivity (4 or 8) Return: boxa, or null on error
Notes: (1) This is the top-level call for getting bounding boxes or a pixa of the components, and it can be used instead of either pixConnCompBB() or pixConnCompPixa(), rsp.
Input: pixs (1 bpp) connectivity (4 or 8) Return: boxa, or null on error
Notes: (1) Finds bounding boxes of 4- or 8-connected components in a binary image. (2) This works on a copy of the input pix. The c.c. are located in raster order and erased one at a time. In the process, the b.b. is computed and saved.
Input: pixs (1 bpp) &pixa (<return> pixa of each c.c.) connectivity (4 or 8) Return: boxa, or null on error
Notes: (1) This finds bounding boxes of 4- or 8-connected components in a binary image, and saves images of each c.c in a pixa array. (2) It sets up 2 temporary pix, and for each c.c. that is located in raster order, it erases the c.c. from one pix, then uses the b.b. to extract the c.c. from the two pix using an XOR, and finally erases the c.c. from the second pix. (3) A clone of the returned boxa (where all boxes in the array are clones) is inserted into the pixa. (4) If the input is valid, this always returns a boxa and a pixa. If pixs is empty, the boxa and pixa will be empty.
Input: pixs (1 bpp) connectivity (4 or 8) &count (<return> Return: 0 if OK, 1 on error
Notes: (1) This is the top-level call for getting the number of 4- or 8-connected components in a 1 bpp image. (2) It works on a copy of the input pix. The c.c. are located in raster order and erased one at a time.
Input: pixs (1 bpp) lstack (for holding fillsegs) x,y (location of seed pixel) connectivity (4 or 8) Return: 0 if OK, 1 on error
Notes: (1) This removes the component from pixs with a fg pixel at (x,y). (2) See pixSeedfill4() and pixSeedfill8() for details.
Input: pixs (1 bpp) lstack (for holding fillsegs) x,y (location of seed pixel) Return: 0 if OK, 1 on error
Notes: (1) This is Paul Heckbert's stack-based 4-cc seedfill algorithm. (2) This operates on the input 1 bpp pix to remove the fg seed pixel, at (x,y), and all pixels that are 4-connected to it. The seed pixel at (x,y) must initially be ON. (3) Reference: see pixSeedFill4BB()
Input: pixs (1 bpp) lstack (for holding fillsegs) x,y (location of seed pixel) Return: box or null on error.
Notes: (1) This is Paul Heckbert's stack-based 4-cc seedfill algorithm. (2) This operates on the input 1 bpp pix to remove the fg seed pixel, at (x,y), and all pixels that are 4-connected to it. The seed pixel at (x,y) must initially be ON. (3) Returns the bounding box of the erased 4-cc component. (4) Reference: see Paul Heckbert's stack-based seed fill algorithm in "Graphic Gems", ed. Andrew Glassner, Academic Press, 1990. The algorithm description is given on pp. 275-277; working C code is on pp. 721-722.) The code here follows Heckbert's exactly, except we use function calls instead of macros for pushing data on and popping data off the stack. This makes sense to do because Heckbert's fixed-size stack with macros is dangerous: images exist that will overrun the stack and crash. The stack utility here grows dynamically as needed, and the fillseg structures that are not in use are stored in another stack for reuse. It should be noted that the overhead in the function calls (vs. macros) is negligible.
Input: pixs (1 bpp) lstack (for holding fillsegs) x,y (location of seed pixel) Return: 0 if OK, 1 on error
Notes: (1) This is Paul Heckbert's stack-based 8-cc seedfill algorithm. (2) This operates on the input 1 bpp pix to remove the fg seed pixel, at (x,y), and all pixels that are 8-connected to it. The seed pixel at (x,y) must initially be ON. (3) Reference: see pixSeedFill8BB()
Input: pixs (1 bpp) lstack (for holding fillsegs) x,y (location of seed pixel) Return: box or null on error.
Notes: (1) This is Paul Heckbert's stack-based 8-cc seedfill algorithm. (2) This operates on the input 1 bpp pix to remove the fg seed pixel, at (x,y), and all pixels that are 8-connected to it. The seed pixel at (x,y) must initially be ON. (3) Returns the bounding box of the erased 8-cc component. (4) Reference: see Paul Heckbert's stack-based seed fill algorithm in "Graphic Gems", ed. Andrew Glassner, Academic Press, 1990. The algorithm description is given on pp. 275-277; working C code is on pp. 721-722.) The code here follows Heckbert's closely, except the leak checks are changed for 8 connectivity. See comments on pixSeedfill4BB() for more details.
Input: pixs (1 bpp) lstack (for holding fillsegs) x,y (location of seed pixel) connectivity (4 or 8) Return: box or null on error
Notes: (1) This is the high-level interface to Paul Heckbert's stack-based seedfill algorithm.
static void popFillseg | ( | L_STACK * | lstack, |
l_int32 * | pxleft, | ||
l_int32 * | pxright, | ||
l_int32 * | py, | ||
l_int32 * | pdy | ||
) | [static] |
Input: lstack &xleft (<return>) &xright (<return>) &y (<return>) &dy (<return>) Return: void
Notes: (1) This removes a line segment from the stack, and returns its size. (2) The surplussed fillseg is placed on the auxiliary stack for future use.
static void pushFillseg | ( | L_STACK * | lstack, |
l_int32 | xleft, | ||
l_int32 | xright, | ||
l_int32 | y, | ||
l_int32 | dy, | ||
l_int32 | ymax | ||
) | [static] |
Input: lstack xleft, xright y dy ymax Return: void
Notes: (1) This adds a line segment to the stack. (2) The auxiliary stack is used as a storage area to recycle fillsegs that are no longer in use. We only calloc new fillsegs if the auxiliary stack is empty.
static void pushFillsegBB | ( | L_STACK * | lstack, |
l_int32 | xleft, | ||
l_int32 | xright, | ||
l_int32 | y, | ||
l_int32 | dy, | ||
l_int32 | ymax, | ||
l_int32 * | pminx, | ||
l_int32 * | pmaxx, | ||
l_int32 * | pminy, | ||
l_int32 * | pmaxy | ||
) | [static] |
Input: lstack xleft, xright y dy ymax, &minx (<return>) &maxx (<return>) &miny (<return>) &maxy (<return>) Return: void
Notes: (1) This adds a line segment to the stack, and returns its size. (2) The auxiliary stack is used as a storage area to recycle fillsegs that are no longer in use. We only calloc new fillsegs if the auxiliary stack is empty.