/*!
* pixEmbedForRotation()
*
* Input: pixs (1, 2, 4, 8, 32 bpp rgb)
* angle (radians; clockwise is positive)
* incolor (L_BRING_IN_WHITE, L_BRING_IN_BLACK)
* width (original width; use 0 to avoid embedding)
* height (original height; use 0 to avoid embedding)
* Return: pixd, or null on error
*
* Notes:
* (1) For very small rotations, just return a clone.
* (2) Generate larger image to embed pixs if necessary, and
* place the center of the input image in the center.
* (3) Rotation brings either white or black pixels in
* from outside the image. For colormapped images where
* there is no white or black, a new color is added if
* possible for these pixels; otherwise, either the
* lightest or darkest color is used. In most cases,
* the colormap will be removed prior to rotation.
* (4) The dest is to be expanded so that no image pixels
* are lost after rotation. Input of the original width
* and height allows the expansion to stop at the maximum
* required size, which is a square with side equal to
* sqrt(w*w + h*h).
* (5) For an arbitrary angle, the expansion can be found by
* considering the UL and UR corners. As the image is
* rotated, these move in an arc centered at the center of
* the image. Normalize to a unit circle by dividing by half
* the image diagonal. After a rotation of T radians, the UL
* and UR corners are at points T radians along the unit
* circle. Compute the x and y coordinates of both these
* points and take the max of absolute values; these represent
* the half width and half height of the containing rectangle.
* The arithmetic is done using formulas for sin(a+b) and cos(a+b),
* where b = T. For the UR corner, sin(a) = h/d and cos(a) = w/d.
* For the UL corner, replace a by (pi - a), and you have
* sin(pi - a) = h/d, cos(pi - a) = -w/d. The equations
* given below follow directly.
*/
PIX *
pixEmbedForRotation(PIX *pixs,
l_float32 angle,
l_int32 incolor,
l_int32 width,
l_int32 height)
{
l_int32 w, h, d, w1, h1, w2, h2, maxside, wnew, hnew, xoff, yoff, setcolor;
l_float64 sina, cosa, fw, fh;
PIX *pixd;
PROCNAME("pixEmbedForRotation");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
if (incolor != L_BRING_IN_WHITE && incolor != L_BRING_IN_BLACK)
return (PIX *)ERROR_PTR("invalid incolor", procName, NULL);
if (L_ABS(angle) < MIN_ANGLE_TO_ROTATE)
return pixClone(pixs);
/* Test if big enough to hold any rotation of the original image */
pixGetDimensions(pixs, &w, &h, &d);
maxside = (l_int32)(sqrt((l_float64)(width * width) +
(l_float64)(height * height)) + 0.5);
if (w >= maxside && h >= maxside) /* big enough */
return pixClone(pixs);
/* Find the new sizes required to hold the image after rotation.
* Note that the new dimensions must be at least as large as those
* of pixs, because we're rasterop-ing into it before rotation. */
cosa = cos(angle);
sina = sin(angle);
fw = (l_float64)w;
fh = (l_float64)h;
w1 = (l_int32)(L_ABS(fw * cosa - fh * sina) + 0.5);
w2 = (l_int32)(L_ABS(-fw * cosa - fh * sina) + 0.5);
h1 = (l_int32)(L_ABS(fw * sina + fh * cosa) + 0.5);
h2 = (l_int32)(L_ABS(-fw * sina + fh * cosa) + 0.5);
wnew = L_MAX(w, L_MAX(w1, w2));
hnew = L_MAX(h, L_MAX(h1, h2));
if ((pixd = pixCreate(wnew, hnew, d)) == NULL)
return (PIX *)ERROR_PTR("pixd not made", procName, NULL);
pixCopyResolution(pixd, pixs);
pixCopyColormap(pixd, pixs);
pixCopySpp(pixd, pixs);
pixCopyText(pixd, pixs);
xoff = (wnew - w) / 2;
yoff = (hnew - h) / 2;
/* Set background to color to be rotated in */
setcolor = (incolor == L_BRING_IN_BLACK) ? L_SET_BLACK : L_SET_WHITE;
pixSetBlackOrWhite(pixd, setcolor);
/* Rasterop automatically handles all 4 channels for rgba */
pixRasterop(pixd, xoff, yoff, w, h, PIX_SRC, pixs, 0, 0);
return pixd;
}
/*!
* pixSelectByWidthHeightRatio()
*
* Input: pixs (1 bpp)
* thresh (threshold ratio of width/height)
* connectivity (4 or 8)
* type (L_SELECT_IF_LT, L_SELECT_IF_GT,
* L_SELECT_IF_LTE, L_SELECT_IF_GTE)
* &changed (<optional return> 1 if changed; 0 if clone returned)
* Return: pixd, or null on error
*
* Notes:
* (1) The args specify constraints on the width-to-height ratio
* for components that are kept.
* (2) If unchanged, returns a copy of pixs. Otherwise,
* returns a new pix with the filtered components.
* (3) This filters components based on the width-to-height ratios.
* (4) Use L_SELECT_IF_LT or L_SELECT_IF_LTE to save components
* with less than the threshold ratio, and
* L_SELECT_IF_GT or L_SELECT_IF_GTE to remove them.
*/
PIX *
pixSelectByWidthHeightRatio(PIX *pixs,
l_float32 thresh,
l_int32 connectivity,
l_int32 type,
l_int32 *pchanged)
{
l_int32 w, h, empty, changed, count;
BOXA *boxa;
PIX *pixd;
PIXA *pixas, *pixad;
PROCNAME("pixSelectByWidthHeightRatio");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
if (connectivity != 4 && connectivity != 8)
return (PIX *)ERROR_PTR("connectivity not 4 or 8", procName, NULL);
if (type != L_SELECT_IF_LT && type != L_SELECT_IF_GT &&
type != L_SELECT_IF_LTE && type != L_SELECT_IF_GTE)
return (PIX *)ERROR_PTR("invalid type", procName, NULL);
if (pchanged) *pchanged = FALSE;
/* Check if any components exist */
pixZero(pixs, &empty);
if (empty)
return pixCopy(NULL, pixs);
/* Filter components */
boxa = pixConnComp(pixs, &pixas, connectivity);
pixad = pixaSelectByWidthHeightRatio(pixas, thresh, type, &changed);
boxaDestroy(&boxa);
pixaDestroy(&pixas);
/* Render the result */
if (!changed) {
pixaDestroy(&pixad);
return pixCopy(NULL, pixs);
}
else {
if (pchanged) *pchanged = TRUE;
pixGetDimensions(pixs, &w, &h, NULL);
count = pixaGetCount(pixad);
if (count == 0) /* return empty pix */
pixd = pixCreateTemplate(pixs);
else {
pixd = pixaDisplay(pixad, w, h);
pixCopyResolution(pixd, pixs);
pixCopyColormap(pixd, pixs);
pixCopyText(pixd, pixs);
pixCopyInputFormat(pixd, pixs);
}
pixaDestroy(&pixad);
return pixd;
}
}
/*!
* pixTransferAllData()
*
* Input: pixd (must be different from pixs)
* &pixs (will be nulled if refcount goes to 0)
* copytext (1 to copy the text field; 0 to skip)
* copyformat (1 to copy the informat field; 0 to skip)
* Return: 0 if OK, 1 on error
*
* Notes:
* (1) This does a complete data transfer from pixs to pixd,
* followed by the destruction of pixs (refcount permitting).
* (2) If the refcount of pixs is 1, pixs is destroyed. Otherwise,
* the data in pixs is copied (rather than transferred) to pixd.
* (3) This operation, like all others with a pre-existing pixd,
* will side-effect any existing clones of pixd. The pixd
* refcount does not change.
* (4) When might you use this? Suppose you have an in-place Pix
* function (returning void) with the typical signature:
* void function-inplace(PIX *pix, ...)
* where "..." are non-pointer input parameters, and suppose
* further that you sometimes want to return an arbitrary Pix
* in place of the input Pix. There are two ways you can do this:
* (a) The straightforward way is to change the function
* signature to take the address of the Pix ptr:
* void function-inplace(PIX **ppix, ...) {
* PIX *pixt = function-makenew(*ppix);
* pixDestroy(ppix);
* *ppix = pixt;
* return;
* }
* Here, the input and returned pix are different, as viewed
* by the calling function, and the inplace function is
* expected to destroy the input pix to avoid a memory leak.
* (b) Keep the signature the same and use pixTransferAllData()
* to return the new Pix in the input Pix struct:
* void function-inplace(PIX *pix, ...) {
* PIX *pixt = function-makenew(pix);
* pixTransferAllData(pix, &pixt); // pixt is destroyed
* return;
* }
* Here, the input and returned pix are the same, as viewed
* by the calling function, and the inplace function must
* never destroy the input pix, because the calling function
* maintains an unchanged handle to it.
*/
l_int32
pixTransferAllData(PIX *pixd,
PIX **ppixs,
l_int32 copytext,
l_int32 copyformat)
{
l_int32 nbytes;
PIX *pixs;
PROCNAME("pixTransferAllData");
if (!ppixs)
return ERROR_INT("&pixs not defined", procName, 1);
if ((pixs = *ppixs) == NULL)
return ERROR_INT("pixs not defined", procName, 1);
if (!pixd)
return ERROR_INT("pixd not defined", procName, 1);
if (pixs == pixd) /* no-op */
return ERROR_INT("pixd == pixs", procName, 1);
if (pixGetRefcount(pixs) == 1) { /* transfer the data, cmap, text */
pixFreeData(pixd); /* dealloc any existing data */
pixSetData(pixd, pixGetData(pixs)); /* transfer new data from pixs */
pixs->data = NULL; /* pixs no longer owns data */
pixSetColormap(pixd, pixGetColormap(pixs)); /* frees old; sets new */
pixs->colormap = NULL; /* pixs no longer owns colormap */
if (copytext) {
pixSetText(pixd, pixGetText(pixs));
pixSetText(pixs, NULL);
}
} else { /* preserve pixs by making a copy of the data, cmap, text */
pixResizeImageData(pixd, pixs);
nbytes = 4 * pixGetWpl(pixs) * pixGetHeight(pixs);
memcpy((char *)pixGetData(pixd), (char *)pixGetData(pixs), nbytes);
pixCopyColormap(pixd, pixs);
if (copytext)
pixCopyText(pixd, pixs);
}
pixCopyResolution(pixd, pixs);
pixCopyDimensions(pixd, pixs);
if (copyformat)
pixCopyInputFormat(pixd, pixs);
/* This will destroy pixs if data was transferred;
* otherwise, it just decrements its refcount. */
pixDestroy(ppixs);
return 0;
}
/*!
* pixCopy()
*
* Input: pixd (<optional>; can be null, or equal to pixs,
* or different from pixs)
* pixs
* Return: pixd, or null on error
*
* Notes:
* (1) There are three cases:
* (a) pixd == null (makes a new pix; refcount = 1)
* (b) pixd == pixs (no-op)
* (c) pixd != pixs (data copy; no change in refcount)
* If the refcount of pixd > 1, case (c) will side-effect
* these handles.
* (2) The general pattern of use is:
* pixd = pixCopy(pixd, pixs);
* This will work for all three cases.
* For clarity when the case is known, you can use:
* (a) pixd = pixCopy(NULL, pixs);
* (c) pixCopy(pixd, pixs);
* (3) For case (c), we check if pixs and pixd are the same
* size (w,h,d). If so, the data is copied directly.
* Otherwise, the data is reallocated to the correct size
* and the copy proceeds. The refcount of pixd is unchanged.
* (4) This operation, like all others that may involve a pre-existing
* pixd, will side-effect any existing clones of pixd.
*/
PIX *
pixCopy(PIX *pixd, /* can be null */
PIX *pixs)
{
l_int32 bytes;
l_uint32 *datas, *datad;
PROCNAME("pixCopy");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
if (pixs == pixd)
return pixd;
/* Total bytes in image data */
bytes = 4 * pixGetWpl(pixs) * pixGetHeight(pixs);
/* If we're making a new pix ... */
if (!pixd) {
if ((pixd = pixCreateTemplate(pixs)) == NULL)
return (PIX *)ERROR_PTR("pixd not made", procName, NULL);
datas = pixGetData(pixs);
datad = pixGetData(pixd);
memcpy((char *)datad, (char *)datas, bytes);
return pixd;
}
/* Reallocate image data if sizes are different */
if (pixResizeImageData(pixd, pixs) == 1)
return (PIX *)ERROR_PTR("reallocation of data failed", procName, NULL);
/* Copy non-image data fields */
pixCopyColormap(pixd, pixs);
pixCopyResolution(pixd, pixs);
pixCopyInputFormat(pixd, pixs);
pixCopyText(pixd, pixs);
/* Copy image data */
datas = pixGetData(pixs);
datad = pixGetData(pixd);
memcpy((char*)datad, (char*)datas, bytes);
return pixd;
}
/*!
* pixCreateTemplateNoInit()
*
* Input: pixs
* Return: pixd, or null on error
*
* Notes:
* (1) Makes a Pix of the same size as the input Pix, with
* the data array allocated but not initialized to 0.
* (2) Copies the other fields, including colormap if it exists.
*/
PIX *
pixCreateTemplateNoInit(PIX *pixs)
{
l_int32 w, h, d;
PIX *pixd;
PROCNAME("pixCreateTemplateNoInit");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
pixGetDimensions(pixs, &w, &h, &d);
if ((pixd = pixCreateNoInit(w, h, d)) == NULL)
return (PIX *)ERROR_PTR("pixd not made", procName, NULL);
pixCopyResolution(pixd, pixs);
pixCopyColormap(pixd, pixs);
pixCopyText(pixd, pixs);
pixCopyInputFormat(pixd, pixs);
return pixd;
}
/*!
* \brief pixSetStrokeWidth()
*
* \param[in] pixs 1 bpp pix
* \param[in] width set stroke width to this value, in [1 ... 100].
* \param[in] thinfirst 1 to thin all pix to a skeleton first; 0 to skip
* \param[in] connectivity 4 or 8, to be used if %thinfirst == 1
* \return pixd with stroke width set to %width, or NULL on error
*
* <pre>
* Notes:
* (1) See notes in pixaSetStrokeWidth().
* (2) A white border of sufficient width to avoid boundary
* artifacts in the thickening step is added before thinning.
* (3) %connectivity == 8 usually gives a slightly smoother result.
* </pre>
*/
PIX *
pixSetStrokeWidth(PIX *pixs,
l_int32 width,
l_int32 thinfirst,
l_int32 connectivity)
{
char buf[16];
l_int32 border;
PIX *pix1, *pix2, *pixd;
PROCNAME("pixSetStrokeWidth");
if (!pixs || (pixGetDepth(pixs) != 1))
return (PIX *)ERROR_PTR("pixs undefined or not 1 bpp", procName, NULL);
if (width < 1 || width > 100)
return (PIX *)ERROR_PTR("width not in [1 ... 100]", procName, NULL);
if (connectivity != 4 && connectivity != 8)
return (PIX *)ERROR_PTR("connectivity not 4 or 8", procName, NULL);
if (!thinfirst && width == 1) /* nothing to do */
return pixCopy(NULL, pixs);
/* Add a white border */
border = width / 2;
pix1 = pixAddBorder(pixs, border, 0);
/* Thin to a skeleton */
if (thinfirst)
pix2 = pixThinConnected(pix1, L_THIN_FG, connectivity, 0);
else
pix2 = pixClone(pix1);
pixDestroy(&pix1);
/* Dilate */
snprintf(buf, sizeof(buf), "D%d.%d", width, width);
pixd = pixMorphSequence(pix2, buf, 0);
pixCopyText(pixd, pixs);
pixDestroy(&pix2);
return pixd;
}
