|
| static BOXA * | findTileRegionsForSearch (BOX *box, l_int32 w, l_int32 h, l_int32 searchdir, l_int32 mindist, l_int32 tsize, l_int32 ntiles) |
| |
| l_ok | pixSetMasked (PIX *pixd, PIX *pixm, l_uint32 val) |
| |
| l_ok | pixSetMaskedGeneral (PIX *pixd, PIX *pixm, l_uint32 val, l_int32 x, l_int32 y) |
| |
| l_ok | pixCombineMasked (PIX *pixd, PIX *pixs, PIX *pixm) |
| |
| l_ok | pixCombineMaskedGeneral (PIX *pixd, PIX *pixs, PIX *pixm, l_int32 x, l_int32 y) |
| |
| l_ok | pixPaintThroughMask (PIX *pixd, PIX *pixm, l_int32 x, l_int32 y, l_uint32 val) |
| |
| l_ok | pixPaintSelfThroughMask (PIX *pixd, PIX *pixm, l_int32 x, l_int32 y, l_int32 searchdir, l_int32 mindist, l_int32 tilesize, l_int32 ntiles, l_int32 distblend) |
| |
| PIX * | pixMakeMaskFromVal (PIX *pixs, l_int32 val) |
| |
| PIX * | pixMakeMaskFromLUT (PIX *pixs, l_int32 *tab) |
| |
| PIX * | pixMakeArbMaskFromRGB (PIX *pixs, l_float32 rc, l_float32 gc, l_float32 bc, l_float32 thresh) |
| |
| PIX * | pixSetUnderTransparency (PIX *pixs, l_uint32 val, l_int32 debug) |
| |
| PIX * | pixMakeAlphaFromMask (PIX *pixs, l_int32 dist, BOX **pbox) |
| |
| l_ok | pixGetColorNearMaskBoundary (PIX *pixs, PIX *pixm, BOX *box, l_int32 dist, l_uint32 *pval, l_int32 debug) |
| |
| PIX * | pixInvert (PIX *pixd, PIX *pixs) |
| |
| PIX * | pixOr (PIX *pixd, PIX *pixs1, PIX *pixs2) |
| |
| PIX * | pixAnd (PIX *pixd, PIX *pixs1, PIX *pixs2) |
| |
| PIX * | pixXor (PIX *pixd, PIX *pixs1, PIX *pixs2) |
| |
| PIX * | pixSubtract (PIX *pixd, PIX *pixs1, PIX *pixs2) |
| |
| l_ok | pixZero (PIX *pix, l_int32 *pempty) |
| |
| l_ok | pixForegroundFraction (PIX *pix, l_float32 *pfract) |
| |
| NUMA * | pixaCountPixels (PIXA *pixa) |
| |
| l_ok | pixCountPixels (PIX *pixs, l_int32 *pcount, l_int32 *tab8) |
| |
| l_ok | pixCountPixelsInRect (PIX *pixs, BOX *box, l_int32 *pcount, l_int32 *tab8) |
| |
| NUMA * | pixCountByRow (PIX *pix, BOX *box) |
| |
| NUMA * | pixCountByColumn (PIX *pix, BOX *box) |
| |
| NUMA * | pixCountPixelsByRow (PIX *pix, l_int32 *tab8) |
| |
| NUMA * | pixCountPixelsByColumn (PIX *pix) |
| |
| l_ok | pixCountPixelsInRow (PIX *pix, l_int32 row, l_int32 *pcount, l_int32 *tab8) |
| |
| NUMA * | pixGetMomentByColumn (PIX *pix, l_int32 order) |
| |
| l_ok | pixThresholdPixelSum (PIX *pix, l_int32 thresh, l_int32 *pabove, l_int32 *tab8) |
| |
| l_int32 * | makePixelSumTab8 (void) |
| |
| l_int32 * | makePixelCentroidTab8 (void) |
| |
| NUMA * | pixAverageByRow (PIX *pix, BOX *box, l_int32 type) |
| |
| NUMA * | pixAverageByColumn (PIX *pix, BOX *box, l_int32 type) |
| |
| l_ok | pixAverageInRect (PIX *pix, BOX *box, l_float32 *pave) |
| |
| NUMA * | pixVarianceByRow (PIX *pix, BOX *box) |
| |
| NUMA * | pixVarianceByColumn (PIX *pix, BOX *box) |
| |
| l_ok | pixVarianceInRect (PIX *pix, BOX *box, l_float32 *prootvar) |
| |
| NUMA * | pixAbsDiffByRow (PIX *pix, BOX *box) |
| |
| NUMA * | pixAbsDiffByColumn (PIX *pix, BOX *box) |
| |
| l_ok | pixAbsDiffInRect (PIX *pix, BOX *box, l_int32 dir, l_float32 *pabsdiff) |
| |
| l_ok | pixAbsDiffOnLine (PIX *pix, l_int32 x1, l_int32 y1, l_int32 x2, l_int32 y2, l_float32 *pabsdiff) |
| |
| l_int32 | pixCountArbInRect (PIX *pixs, BOX *box, l_int32 val, l_int32 factor, l_int32 *pcount) |
| |
| PIX * | pixMirroredTiling (PIX *pixs, l_int32 w, l_int32 h) |
| |
| l_ok | pixFindRepCloseTile (PIX *pixs, BOX *box, l_int32 searchdir, l_int32 mindist, l_int32 tsize, l_int32 ntiles, BOX **pboxtile, l_int32 debug) |
| |
This file has these operations:
(1) Mask-directed operations
(2) Full-image bit-logical operations
(3) Foreground pixel counting operations on 1 bpp images
(4) Average and variance of pixel values
(5) Mirrored tiling of a smaller image Masked operations
l_int32 pixSetMasked()
l_int32 pixSetMaskedGeneral()
l_int32 pixCombineMasked()
l_int32 pixCombineMaskedGeneral()
l_int32 pixPaintThroughMask()
PIX *pixPaintSelfThroughMask()
PIX *pixMakeMaskFromVal()
PIX *pixMakeMaskFromLUT()
PIX *pixMakeArbMaskFromRGB()
PIX *pixSetUnderTransparency()
PIX *pixMakeAlphaFromMask()
l_int32 pixGetColorNearMaskBoundary() One and two-image boolean operations on arbitrary depth images
PIX *pixInvert()
PIX *pixOr()
PIX *pixAnd()
PIX *pixXor()
PIX *pixSubtract() Foreground pixel counting in 1 bpp images
l_int32 pixZero()
l_int32 pixForegroundFraction()
NUMA *pixaCountPixels()
l_int32 pixCountPixels()
l_int32 pixCountPixelsInRect()
NUMA *pixCountByRow()
NUMA *pixCountByColumn()
NUMA *pixCountPixelsByRow()
NUMA *pixCountPixelsByColumn()
l_int32 pixCountPixelsInRow()
NUMA *pixGetMomentByColumn()
l_int32 pixThresholdPixelSum()
l_int32 *makePixelSumTab8()
l_int32 *makePixelCentroidTab8() Average of pixel values in gray images
NUMA *pixAverageByRow()
NUMA *pixAverageByColumn()
l_int32 pixAverageInRect() Variance of pixel values in gray images
NUMA *pixVarianceByRow()
NUMA *pixVarianceByColumn()
l_int32 pixVarianceInRect() Average of absolute value of pixel differences in gray images
NUMA *pixAbsDiffByRow()
NUMA *pixAbsDiffByColumn()
l_int32 pixAbsDiffInRect()
l_int32 pixAbsDiffOnLine() Count of pixels with specific value
l_int32 pixCountArbInRect() Mirrored tiling
PIX *pixMirroredTiling() Representative tile near but outside region
l_int32 pixFindRepCloseTile() Static helper function
static BOXA *findTileRegionsForSearch()
Definition in file pix3.c.
pixAnd()
- Parameters
-
| [in] | pixd | [optional]; this can be null, equal to pixs1, different from pixs1 |
| [in] | pixs1 | can be == pixd |
| [in] | pixs2 | must be != pixd |
- Returns
- pixd always
Notes:
(1) This gives the intersection of two images with equal depth,
aligning them to the the UL corner. pixs1 and pixs2
need not have the same width and height.
(2) There are 3 cases:
(a) pixd == null, (src1 & src2) –> new pixd
(b) pixd == pixs1, (src1 & src2) –> src1 (in-place)
(c) pixd != pixs1, (src1 & src2) –> input pixd
(3) For clarity, if the case is known, use these patterns:
(a) pixd = pixAnd(NULL, pixs1, pixs2);
(b) pixAnd(pixs1, pixs1, pixs2);
(c) pixAnd(pixd, pixs1, pixs2);
(4) The size of the result is determined by pixs1.
(5) The depths of pixs1 and pixs2 must be equal.
(6) Note carefully that the order of pixs1 and pixs2 only matters
for the in-place case. For in-place, you must have
pixd == pixs1. Setting pixd == pixs2 gives an incorrect
result: the copy puts pixs1 image data in pixs2, and
the rasterop is then between pixs2 and pixs2 (a no-op).
Definition at line 1510 of file pix3.c.
Referenced by boxaCompareRegions(), pixaClipToPix(), pixCorrelationBinary(), and pixDisplayDiffBinary().
| l_ok pixCombineMasked |
( |
PIX * |
pixd, |
|
|
PIX * |
pixs, |
|
|
PIX * |
pixm |
|
) |
| |
pixCombineMasked()
- Parameters
-
| [in] | pixd | 1 bpp, 8 bpp gray or 32 bpp rgb; no cmap |
| [in] | pixs | 1 bpp, 8 bpp gray or 32 bpp rgb; no cmap |
| [in] | pixm | [optional] 1 bpp mask; no operation if NULL |
- Returns
- 0 if OK; 1 on error
Notes:
(1) In-place operation; pixd is changed.
(2) This sets each pixel in pixd that co-locates with an ON
pixel in pixm to the corresponding value of pixs.
(3) pixs and pixd must be the same depth and not colormapped.
(4) All three input pix are aligned at the UL corner, and the
operation is clipped to the intersection of all three images.
(5) If pixm == NULL, it's a no-op.
(6) Implementation: see notes in pixCombineMaskedGeneral().
For 8 bpp selective masking, you might guess that it
would be faster to generate an 8 bpp version of pixm,
using pixConvert1To8(pixm, 0, 255), and then use a
general combine operation
d = (d & ~m) | (s & m)
on a word-by-word basis. Not always. The word-by-word
combine takes a time that is independent of the mask data.
If the mask is relatively sparse, the byte-check method
is actually faster!
Definition at line 374 of file pix3.c.
References pixGetDimensions().
Referenced by pixMorphSequenceMasked(), and wshedRenderColors().
| l_ok pixCombineMaskedGeneral |
( |
PIX * |
pixd, |
|
|
PIX * |
pixs, |
|
|
PIX * |
pixm, |
|
|
l_int32 |
x, |
|
|
l_int32 |
y |
|
) |
| |
pixCombineMaskedGeneral()
- Parameters
-
| [in] | pixd | 1 bpp, 8 bpp gray or 32 bpp rgb |
| [in] | pixs | 1 bpp, 8 bpp gray or 32 bpp rgb |
| [in] | pixm | [optional] 1 bpp mask |
| [in] | x,y | origin of pixs and pixm relative to pixd; can be negative |
- Returns
- 0 if OK; 1 on error
Notes:
(1) In-place operation; pixd is changed.
(2) This is a generalized version of pixCombinedMasked(), where
the source and mask can be placed at the same (arbitrary)
location relative to pixd.
(3) pixs and pixd must be the same depth and not colormapped.
(4) The UL corners of both pixs and pixm are aligned with
the point (x, y) of pixd, and the operation is clipped to
the intersection of all three images.
(5) If pixm == NULL, it's a no-op.
(6) Implementation. There are two ways to do these. In the first,
we use rasterop, ORing the part of pixs under the mask
with pixd (which has been appropriately cleared there first).
In the second, the mask is used one pixel at a time to
selectively replace pixels of pixd with those of pixs.
Here, we use rasterop for 1 bpp and pixel-wise replacement
for 8 and 32 bpp. To use rasterop for 8 bpp, for example,
we must first generate an 8 bpp version of the mask.
The code is simple: Pix *pixm8 = pixConvert1To8(NULL, pixm, 0, 255);
Pix *pixt = pixAnd(NULL, pixs, pixm8);
pixRasterop(pixd, x, y, wmin, hmin, PIX_DST & PIX_NOT(PIX_SRC),
pixm8, 0, 0);
pixRasterop(pixd, x, y, wmin, hmin, PIX_SRC | PIX_DST,
pixt, 0, 0);
pixDestroy(&pixt);
pixDestroy(&pixm8);
Definition at line 493 of file pix3.c.
References pixGetDimensions().
pixInvert()
- Parameters
-
| [in] | pixd | [optional]; this can be null, equal to pixs, or different from pixs |
| [in] | pixs | |
- Returns
- pixd, or NULL on error
Notes:
(1) This inverts pixs, for all pixel depths.
(2) There are 3 cases:
(a) pixd == null, ~src –> new pixd
(b) pixd == pixs, ~src –> src (in-place)
(c) pixd != pixs, ~src –> input pixd
(3) For clarity, if the case is known, use these patterns:
(a) pixd = pixInvert(NULL, pixs);
(b) pixInvert(pixs, pixs);
(c) pixInvert(pixd, pixs);
Definition at line 1395 of file pix3.c.
References pixCopy(), and pixRasterop().
Referenced by ccbaDisplayImage1(), ccbaDisplayImage2(), pixBlockrank(), pixDecideIfTable(), pixThresholdForFgBg(), and recogAverageSamples().
| PIX* pixMakeAlphaFromMask |
( |
PIX * |
pixs, |
|
|
l_int32 |
dist, |
|
|
BOX ** |
pbox |
|
) |
| |
pixMakeAlphaFromMask()
- Parameters
-
| [in] | pixs | 1 bpp |
| [in] | dist | blending distance; typically 10 - 30 |
| [out] | pbox | [optional] use NULL to get the full size |
- Returns
- pixd (8 bpp gray, or NULL on error
Notes:
(1) This generates a 8 bpp alpha layer that is opaque (256)
over the FG of pixs, and goes transparent linearly away
from the FG pixels, decaying to 0 (transparent) is an
8-connected distance given by dist. If dist == 0,
this does a simple conversion from 1 to 8 bpp.
(2) If &box == NULL, this returns an alpha mask that is the
full size of pixs. Otherwise, the returned mask pixd covers
just the FG pixels of pixs, expanded by dist in each
direction (if possible), and the returned box gives the
location of the returned mask relative to pixs.
(3) This is useful for painting through a mask and allowing
blending of the painted image with an underlying image
in the mask background for pixels near foreground mask pixels.
For example, with an underlying rgb image pix1, an overlaying
image rgb pix2, binary mask pixm, and dist > 0, this
blending is achieved with:
pix3 = pixMakeAlphaFromMask(pixm, dist, &box);
boxGetGeometry(box, &x, &y, NULL, NULL);
pix4 = pixBlendWithGrayMask(pix1, pix2, pix3, x, y);
Definition at line 1222 of file pix3.c.
pixOr()
- Parameters
-
| [in] | pixd | [optional]; this can be null, equal to pixs1, different from pixs1 |
| [in] | pixs1 | can be == pixd |
| [in] | pixs2 | must be != pixd |
- Returns
- pixd always
Notes:
(1) This gives the union of two images with equal depth,
aligning them to the the UL corner. pixs1 and pixs2
need not have the same width and height.
(2) There are 3 cases:
(a) pixd == null, (src1 | src2) –> new pixd
(b) pixd == pixs1, (src1 | src2) –> src1 (in-place)
(c) pixd != pixs1, (src1 | src2) –> input pixd
(3) For clarity, if the case is known, use these patterns:
(a) pixd = pixOr(NULL, pixs1, pixs2);
(b) pixOr(pixs1, pixs1, pixs2);
(c) pixOr(pixd, pixs1, pixs2);
(4) The size of the result is determined by pixs1.
(5) The depths of pixs1 and pixs2 must be equal.
(6) Note carefully that the order of pixs1 and pixs2 only matters
for the in-place case. For in-place, you must have
pixd == pixs1. Setting pixd == pixs2 gives an incorrect
result: the copy puts pixs1 image data in pixs2, and
the rasterop is then between pixs2 and pixs2 (a no-op).
Definition at line 1446 of file pix3.c.
Referenced by pixDecideIfTable().
| l_ok pixPaintSelfThroughMask |
( |
PIX * |
pixd, |
|
|
PIX * |
pixm, |
|
|
l_int32 |
x, |
|
|
l_int32 |
y, |
|
|
l_int32 |
searchdir, |
|
|
l_int32 |
mindist, |
|
|
l_int32 |
tilesize, |
|
|
l_int32 |
ntiles, |
|
|
l_int32 |
distblend |
|
) |
| |
pixPaintSelfThroughMask()
- Parameters
-
| [in] | pixd | 8 bpp gray or 32 bpp rgb; not colormapped |
| [in] | pixm | 1 bpp mask |
| [in] | x,y | origin of pixm relative to pixd; must not be negative |
| [in] | searchdir | L_HORIZ, L_VERT or L_BOTH_DIRECTIONS |
| [in] | mindist | min distance of nearest tile edge to box; >= 0 |
| [in] | tilesize | requested size for tiling; may be reduced |
| [in] | ntiles | number of tiles tested in each row/column |
| [in] | distblend | distance outside the fg used for blending with pixs |
- Returns
- 0 if OK; 1 on error
Notes:
(1) In-place operation; pixd is changed.
(2) If pixm == NULL, it's a no-op.
(3) The mask origin is placed at (x,y) on pixd, and the
operation is clipped to the intersection of pixd and the
fg of the mask.
(4) tsize is the the requested size for tiling. The actual
actual size for each c.c. will be bounded by the minimum
dimension of the c.c.
(5) For mindist, searchdir and ntiles, see pixFindRepCloseTile().
They determine the set of possible tiles that can be used
to build a larger mirrored tile to paint onto pixd through
the c.c. of pixm.
(6) distblend is used for alpha blending. It is only applied
if there is exactly one c.c. in the mask. Use distblend == 0
to skip blending and just paint through the 1 bpp mask.
(7) To apply blending to more than 1 component, call this function
repeatedly with pixm, x and y representing one component of
the mask each time. This would be done as follows, for an
underlying image pixs and mask pixm of components to fill:
Boxa *boxa = pixConnComp(pixm, &pixa, 8);
n = boxaGetCount(boxa);
for (i = 0; i < n; i++) {
Pix *pix = pixaGetPix(pixa, i, L_CLONE);
Box *box = pixaGetBox(pixa, i, L_CLONE);
boxGetGeometry(box, &bx, &by, &bw, &bh);
pixPaintSelfThroughMask(pixs, pix, bx, by, searchdir,
mindist, tilesize, ntiles, distblend);
pixDestroy(&pix);
boxDestroy(&box);
}
pixaDestroy(&pixa);
boxaDestroy(&boxa);
(8) If no tiles can be found, this falls back to estimating the
color near the boundary of the region to be textured.
(9) This can be used to replace the pixels in some regions of
an image by selected neighboring pixels. The mask represents
the pixels to be replaced. For each connected component in
the mask, this function selects up to two tiles of neighboring
pixels to be used for replacement of pixels represented by
the component (i.e., under the FG of that component in the mask).
After selection, mirror replication is used to generate an
image that is large enough to cover the component. Alpha
blending can also be used outside of the component, but near the
edge, to blur the transition between painted and original pixels.
Definition at line 786 of file pix3.c.
| l_ok pixPaintThroughMask |
( |
PIX * |
pixd, |
|
|
PIX * |
pixm, |
|
|
l_int32 |
x, |
|
|
l_int32 |
y, |
|
|
l_uint32 |
val |
|
) |
| |
pixPaintThroughMask()
- Parameters
-
| [in] | pixd | 1, 2, 4, 8, 16 or 32 bpp; or colormapped |
| [in] | pixm | [optional] 1 bpp mask |
| [in] | x,y | origin of pixm relative to pixd; can be negative |
| [in] | val | pixel value to set at each masked pixel |
- Returns
- 0 if OK; 1 on error
Notes:
(1) In-place operation. Calls pixSetMaskedCmap() for colormapped
images.
(2) For 1, 2, 4, 8 and 16 bpp gray, we take the appropriate
number of least significant bits of val.
(3) If pixm == NULL, it's a no-op.
(4) The mask origin is placed at (x,y) on pixd, and the
operation is clipped to the intersection of rectangles.
(5) For rgb, the components in val are in the canonical locations,
with red in location COLOR_RED, etc.
(6) Implementation detail 1:
For painting with val == 0 or val == maxval, you can use rasterop.
If val == 0, invert the mask so that it's 0 over the region
into which you want to write, and use PIX_SRC & PIX_DST to
clear those pixels. To write with val = maxval (all 1's),
use PIX_SRC | PIX_DST to set all bits under the mask.
(7) Implementation detail 2:
The rasterop trick can be used for depth > 1 as well.
For val == 0, generate the mask for depth d from the binary
mask using
pixmd = pixUnpackBinary(pixm, d, 1);
and use pixRasterop() with PIX_MASK. For val == maxval,
pixmd = pixUnpackBinary(pixm, d, 0);
and use pixRasterop() with PIX_PAINT.
But note that if d == 32 bpp, it is about 3x faster to use
the general implementation (not pixRasterop()).
(8) Implementation detail 3:
It might be expected that the switch in the inner loop will
cause large branching delays and should be avoided.
This is not the case, because the entrance is always the
same and the compiler can correctly predict the jump.
Definition at line 618 of file pix3.c.
Referenced by boxaCompareRegions(), kernelDisplayInPix(), pixDisplayDiffBinary(), recogShowPath(), selaAddCrossJunctions(), selaAddTJunctions(), and wshedRenderFill().
| PIX* pixSetUnderTransparency |
( |
PIX * |
pixs, |
|
|
l_uint32 |
val, |
|
|
l_int32 |
debug |
|
) |
| |
pixSetUnderTransparency()
- Parameters
-
| [in] | pixs | 32 bpp rgba |
| [in] | val | 32 bit unsigned color to use where alpha == 0 |
| [in] | debug | displays layers of pixs |
- Returns
- pixd 32 bpp rgba, or NULL on error
Notes:
(1) This sets the r, g and b components under every fully
transparent alpha component to val. The alpha components
are unchanged.
(2) Full transparency is denoted by alpha == 0. Setting
all pixels to a constant val where alpha is transparent
can improve compressibility by reducing the entropy.
(3) The visual result depends on how the image is displayed.
(a) For display devices that respect the use of the alpha
layer, this will not affect the appearance.
(b) For typical leptonica operations, alpha is ignored,
so there will be a change in appearance because this
resets the rgb values in the fully transparent region.
(4) pixRead() and pixWrite() will, by default, read and write
4-component (rgba) pix in png format. To ignore the alpha
component after reading, or omit it on writing, pixSetSpp(..., 3).
(5) Here are some examples:
* To convert all fully transparent pixels in a 4 component
(rgba) png file to white:
pixs = pixRead(<infile>);
pixd = pixSetUnderTransparency(pixs, 0xffffff00, 0);
* To write pixd with the alpha component:
pixWrite(<outfile>, pixd, IFF_PNG);
* To write and rgba image without the alpha component, first do:
pixSetSpp(pixd, 3);
If you later want to use the alpha, spp must be reset to 4.
* (fancier) To remove the alpha by blending the image over
a white background:
pixRemoveAlpha()
This changes all pixel values where the alpha component is
not opaque (255).
(6) Caution. rgb images in leptonica typically have value 0 in
the alpha channel, which is fully transparent. If spp for
such an image were changed from 3 to 4, the image becomes
fully transparent, and this function will set each pixel to val.
If you really want to set every pixel to the same value,
use pixSetAllArbitrary().
(7) This is useful for compressing an RGBA image where the part
of the image that is fully transparent is random junk; compression
is typically improved by setting that region to a constant.
For rendering as a 3 component RGB image over a uniform
background of arbitrary color, use pixAlphaBlendUniform().
Definition at line 1146 of file pix3.c.
pixSubtract()
- Parameters
-
| [in] | pixd | [optional]; this can be null, equal to pixs1, equal to pixs2, or different from both pixs1 and pixs2 |
| [in] | pixs1 | can be == pixd |
| [in] | pixs2 | can be == pixd |
- Returns
- pixd always
Notes:
(1) This gives the set subtraction of two images with equal depth,
aligning them to the the UL corner. pixs1 and pixs2
need not have the same width and height.
(2) Source pixs2 is always subtracted from source pixs1.
The result is
pixs1 \ pixs2 = pixs1 & (~pixs2)
(3) There are 4 cases:
(a) pixd == null, (src1 - src2) –> new pixd
(b) pixd == pixs1, (src1 - src2) –> src1 (in-place)
(c) pixd == pixs2, (src1 - src2) –> src2 (in-place)
(d) pixd != pixs1 && pixd != pixs2),
(src1 - src2) –> input pixd
(4) For clarity, if the case is known, use these patterns:
(a) pixd = pixSubtract(NULL, pixs1, pixs2);
(b) pixSubtract(pixs1, pixs1, pixs2);
(c) pixSubtract(pixs2, pixs1, pixs2);
(d) pixSubtract(pixd, pixs1, pixs2);
(5) The size of the result is determined by pixs1.
(6) The depths of pixs1 and pixs2 must be equal.
Definition at line 1639 of file pix3.c.
Referenced by pixDecideIfTable(), pixDisplayDiffBinary(), and selDisplayInPix().
pixXor()
- Parameters
-
| [in] | pixd | [optional]; this can be null, equal to pixs1, different from pixs1 |
| [in] | pixs1 | can be == pixd |
| [in] | pixs2 | must be != pixd |
- Returns
- pixd always
Notes:
(1) This gives the XOR of two images with equal depth,
aligning them to the the UL corner. pixs1 and pixs2
need not have the same width and height.
(2) There are 3 cases:
(a) pixd == null, (src1 ^ src2) –> new pixd
(b) pixd == pixs1, (src1 ^ src2) –> src1 (in-place)
(c) pixd != pixs1, (src1 ^ src2) –> input pixd
(3) For clarity, if the case is known, use these patterns:
(a) pixd = pixXor(NULL, pixs1, pixs2);
(b) pixXor(pixs1, pixs1, pixs2);
(c) pixXor(pixd, pixs1, pixs2);
(4) The size of the result is determined by pixs1.
(5) The depths of pixs1 and pixs2 must be equal.
(6) Note carefully that the order of pixs1 and pixs2 only matters
for the in-place case. For in-place, you must have
pixd == pixs1. Setting pixd == pixs2 gives an incorrect
result: the copy puts pixs1 image data in pixs2, and
the rasterop is then between pixs2 and pixs2 (a no-op).
Definition at line 1574 of file pix3.c.
Referenced by boxaCompareRegions(), pixExtractBoundary(), and recogShowPath().
1.8.14