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Leptonica 1.85.0
Image processing and image analysis suite
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Leptonica 1.85.0
Image processing and image analysis suite
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Go to the source code of this file.
Data Structures | |
| struct | PixMemoryManager |
Functions | |
| static void | pixFree (PIX *pix) |
| static void * | pixdata_malloc (size_t size) |
| static void | pixdata_free (void *ptr) |
| void | setPixMemoryManager (alloc_fn allocator, dealloc_fn deallocator) |
| PIX * | pixCreate (l_int32 width, l_int32 height, l_int32 depth) |
| PIX * | pixCreateNoInit (l_int32 width, l_int32 height, l_int32 depth) |
| PIX * | pixCreateTemplate (const PIX *pixs) |
| PIX * | pixCreateTemplateNoInit (const PIX *pixs) |
| PIX * | pixCreateWithCmap (l_int32 width, l_int32 height, l_int32 depth, l_int32 initcolor) |
| PIX * | pixCreateHeader (l_int32 width, l_int32 height, l_int32 depth) |
| PIX * | pixClone (PIX *pixs) |
| void | pixDestroy (PIX **ppix) |
| PIX * | pixCopy (PIX *pixd, const PIX *pixs) |
| l_ok | pixResizeImageData (PIX *pixd, const PIX *pixs) |
| l_ok | pixCopyColormap (PIX *pixd, const PIX *pixs) |
| l_ok | pixTransferAllData (PIX *pixd, PIX **ppixs, l_int32 copytext, l_int32 copyformat) |
| l_ok | pixSwapAndDestroy (PIX **ppixd, PIX **ppixs) |
| l_int32 | pixGetWidth (const PIX *pix) |
| l_int32 | pixSetWidth (PIX *pix, l_int32 width) |
| l_int32 | pixGetHeight (const PIX *pix) |
| l_int32 | pixSetHeight (PIX *pix, l_int32 height) |
| l_int32 | pixGetDepth (const PIX *pix) |
| l_int32 | pixSetDepth (PIX *pix, l_int32 depth) |
| l_ok | pixGetDimensions (const PIX *pix, l_int32 *pw, l_int32 *ph, l_int32 *pd) |
| l_ok | pixSetDimensions (PIX *pix, l_int32 w, l_int32 h, l_int32 d) |
| l_ok | pixCopyDimensions (PIX *pixd, const PIX *pixs) |
| l_int32 | pixGetSpp (const PIX *pix) |
| l_int32 | pixSetSpp (PIX *pix, l_int32 spp) |
| l_ok | pixCopySpp (PIX *pixd, const PIX *pixs) |
| l_int32 | pixGetWpl (const PIX *pix) |
| l_int32 | pixSetWpl (PIX *pix, l_int32 wpl) |
| l_int32 | pixGetXRes (const PIX *pix) |
| l_int32 | pixSetXRes (PIX *pix, l_int32 res) |
| l_int32 | pixGetYRes (const PIX *pix) |
| l_int32 | pixSetYRes (PIX *pix, l_int32 res) |
| l_ok | pixGetResolution (const PIX *pix, l_int32 *pxres, l_int32 *pyres) |
| l_ok | pixSetResolution (PIX *pix, l_int32 xres, l_int32 yres) |
| l_int32 | pixCopyResolution (PIX *pixd, const PIX *pixs) |
| l_int32 | pixScaleResolution (PIX *pix, l_float32 xscale, l_float32 yscale) |
| l_int32 | pixGetInputFormat (const PIX *pix) |
| l_int32 | pixSetInputFormat (PIX *pix, l_int32 informat) |
| l_int32 | pixCopyInputFormat (PIX *pixd, const PIX *pixs) |
| l_int32 | pixSetSpecial (PIX *pix, l_int32 special) |
| char * | pixGetText (PIX *pix) |
| l_ok | pixSetText (PIX *pix, const char *textstring) |
| l_ok | pixAddText (PIX *pix, const char *textstring) |
| l_int32 | pixCopyText (PIX *pixd, const PIX *pixs) |
| l_uint8 * | pixGetTextCompNew (PIX *pix, size_t *psize) |
| l_ok | pixSetTextCompNew (PIX *pix, const l_uint8 *data, size_t size) |
| PIXCMAP * | pixGetColormap (PIX *pix) |
| l_ok | pixSetColormap (PIX *pix, PIXCMAP *colormap) |
| l_ok | pixDestroyColormap (PIX *pix) |
| l_uint32 * | pixGetData (PIX *pix) |
| l_int32 | pixFreeAndSetData (PIX *pix, l_uint32 *data) |
| l_int32 | pixSetData (PIX *pix, l_uint32 *data) |
| l_int32 | pixFreeData (PIX *pix) |
| l_uint32 * | pixExtractData (PIX *pixs) |
| void ** | pixGetLinePtrs (PIX *pix, l_int32 *psize) |
| l_int32 | pixSizesEqual (const PIX *pix1, const PIX *pix2) |
| l_ok | pixMaxAspectRatio (PIX *pixs, l_float32 *pratio) |
| l_ok | pixPrintStreamInfo (FILE *fp, const PIX *pix, const char *text) |
Variables | |
| static struct PixMemoryManager | pix_mem_manager |
| const char * | ImageFileFormatExtensions [] |
The pixN.c {N = 1,2,3,4,5} files are sorted by the type of operation.
The primary functions in these files are:
pix1.c: constructors, destructors and field accessors
pix2.c: pixel poking of image, pad and border pixels
pix3.c: masking and logical ops, counting, mirrored tiling
pix4.c: histograms, statistics, fg/bg estimation
pix5.c: property measurements, rectangle extraction
This file has the basic constructors, destructors and field accessors
Pix memory management (allows custom allocator and deallocator)
static void *pixdata_malloc()
static void pixdata_free()
void setPixMemoryManager()
Pix creation
PIX *pixCreate()
PIX *pixCreateNoInit()
PIX *pixCreateTemplate()
PIX *pixCreateTemplateNoInit()
PIX *pixCreateWithCmap()
PIX *pixCreateHeader()
PIX *pixClone()
Pix destruction
void pixDestroy()
static void pixFree()
Pix copy
PIX *pixCopy()
l_int32 pixResizeImageData()
l_int32 pixCopyColormap()
l_int32 pixTransferAllData()
l_int32 pixSwapAndDestroy()
Pix accessors
l_int32 pixGetWidth()
l_int32 pixSetWidth()
l_int32 pixGetHeight()
l_int32 pixSetHeight()
l_int32 pixGetDepth()
l_int32 pixSetDepth()
l_int32 pixGetDimensions()
l_int32 pixSetDimensions()
l_int32 pixCopyDimensions()
l_int32 pixGetSpp()
l_int32 pixSetSpp()
l_int32 pixCopySpp()
l_int32 pixGetWpl()
l_int32 pixSetWpl()
l_uint32 pixGetXRes()
l_int32 pixSetXRes()
l_uint32 pixGetYRes()
l_int32 pixSetYRes()
l_int32 pixGetResolution()
l_int32 pixSetResolution()
l_int32 pixCopyResolution()
l_int32 pixScaleResolution()
l_int32 pixGetInputFormat()
l_int32 pixSetInputFormat()
l_int32 pixCopyInputFormat()
l_int32 pixSetSpecial()
char *pixGetText()
l_int32 pixSetText()
l_int32 pixAddText()
l_int32 pixCopyText()
l_uint8 *pixGetTextCompNew()
l_int32 *pixSetTextCompNew()
PIXCMAP *pixGetColormap()
l_int32 pixSetColormap()
l_int32 pixDestroyColormap()
l_uint32 *pixGetData()
l_int32 pixFreeAndSetData()
l_int32 pixSetData()
l_int32 pixFreeData()
l_uint32 *pixExtractData()
Pix line ptrs
void **pixGetLinePtrs()
Pix size comparisons
l_int32 pixSizesEqual()
l_int32 pixMaxAspectRatio()
Pix debug
l_int32 pixPrintStreamInfo()
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Important notes on direct management of pix image data
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Custom allocator and deallocator
--------------------------------
At the lowest level, you can specify the function that does the
allocation and deallocation of the data field in the pix.
By default, this is malloc and free. However, by calling
setPixMemoryManager(), custom functions can be substituted.
When using this, keep two things in mind:
(1) Call setPixMemoryManager() before any pix have been allocated
(2) Destroy all pix as usual, in order to prevent leaks.
In pixalloc.c, we provide an example custom allocator and deallocator.
To use it, you must call pmsCreate() before any pix have been allocated
and pmsDestroy() at the end after all pix have been destroyed.
Direct manipulation of the pix data field
-----------------------------------------
Memory management of the (image) data field in the pix is
handled differently from that in the colormap and text fields.
For colormap and text, the functions pixSetColormap() and
pixSetText() remove the existing heap data and insert the
new data. For the image data, pixSetData() just reassigns the
data field; any existing data will be lost if there isn't
another handle for it.
Why is pixSetData() limited in this way? Because the image
data can be very large, we need flexible ways to handle it,
particularly when you want to re-use the data in a different
context without making a copy. Here are some different
things you might want to do:
(1) Use pixCopy(pixd, pixs) where pixd is not the same size
as pixs. This will remove the data in pixd, allocate a
new data field in pixd, and copy the data from pixs, leaving
pixs unchanged.
(2) Use pixTransferAllData(pixd, &pixs, ...) to transfer the
data from pixs to pixd without making a copy of it. If
pixs is not cloned, this will do the transfer and destroy pixs.
But if the refcount of pixs is greater than 1, it just copies
the data and decrements the ref count.
(3) Use pixSwapAndDestroy(pixd, &pixs) to replace pixs by an
existing pixd. This is similar to pixTransferAllData(), but
simpler, in that it never makes any copies and if pixs is
cloned, the other references are not changed by this operation.
(4) Use pixExtractData() to extract the image data from the pix
without copying if possible. This could be used, for example,
to convert from a pix to some other data structure with minimal
heap allocation. After the data is extracated, the pixels can
be munged and used in another context. However, the danger
here is that the pix might have a refcount > 1, in which case
a copy of the data must be made and the input pix left unchanged.
If there are no clones, the image data can be extracted without
a copy, and the data ptr in the pix must be nulled before
destroying it because the pix will no longer 'own' the data.
We have provided accessors and functions here that should be
sufficient so that you can do anything you want without
explicitly referencing any of the pix member fields.
However, to avoid memory smashes and leaks when doing special operations
on the pix data field, look carefully at the behavior of the image
data accessors and keep in mind that when you invoke pixDestroy(),
the pix considers itself the owner of all its heap data.
Definition in file pix1.c.
| l_ok pixAddText | ( | PIX * | pix, |
| const char * | textstring ) |
| [in] | pix | |
| [in] | textstring | can be null |
Notes:
(1) This adds the new textstring to any existing text.
(2) Either or both the existing text and the new text
string can be null.
Definition at line 1457 of file pix1.c.
References pixGetText(), and Pix::text.
| [in] | pixs |
Notes:
(1) A "clone" is simply a handle (ptr) to an existing pix.
It is implemented because (a) images can be large and
hence expensive to copy, and (b) extra handles to a data
structure need to be made with a simple policy to avoid
both double frees and memory leaks. Pix are reference
counted. The side effect of pixClone() is an increase
by 1 in the ref count.
(2) The protocol to be used is:
(a) Whenever you want a new handle to an existing image,
call pixClone(), which just bumps a ref count.
(b) Always call pixDestroy() on all handles. This
decrements the ref count, nulls the handle, and
only destroys the pix when pixDestroy() has been
called on all handles.
Definition at line 583 of file pix1.c.
References Pix::refcount.
Referenced by pixSwapAndDestroy().
| [in] | pixd | [optional] can be null, equal to pixs, different from pixs |
| [in] | pixs |
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.
Definition at line 690 of file pix1.c.
References Pix::data, pixCopyColormap(), pixCopySpp(), pixCreateTemplate(), and pixResizeImageData().
| [in] | pixd | |
| [in] | pixs | copies the colormap to pixd |
Notes:
(1) This destroys the colormap in pixd, unless the operation is a no-op
Definition at line 796 of file pix1.c.
References Pix::colormap, pixDestroyColormap(), and pixSetColormap().
Referenced by pixCopy(), pixCreateTemplateNoInit(), and pixTransferAllData().
| [in] | pixd | |
| [in] | pixs |
Definition at line 1122 of file pix1.c.
Referenced by pixTransferAllData().
| [in] | pixd | |
| [in] | pixs |
Definition at line 1188 of file pix1.c.
Referenced by pixCopy(), pixCreateTemplateNoInit(), and pixTransferAllData().
| PIX * pixCreate | ( | l_int32 | width, |
| l_int32 | height, | ||
| l_int32 | depth ) |
| [in] | width,height,depth |
Definition at line 315 of file pix1.c.
References Pix::data, Pix::h, pixCreateNoInit(), and Pix::wpl.
Referenced by pixCreateWithCmap().
| PIX * pixCreateHeader | ( | l_int32 | width, |
| l_int32 | height, | ||
| l_int32 | depth ) |
| [in] | width,height,depth |
Notes:
(1) It is assumed that all 32 bit pix have 3 spp. If there is
a valid alpha channel, this will be set to 4 spp later.
(2) All pixCreate*() functions call pixCreateHeader().
If the number of bytes to be allocated is larger than the
maximum value in an int32, we can get overflow, resulting
in a smaller amount of memory actually being allocated.
Later, an attempt to access memory that wasn't allocated will
cause a crash. So to avoid crashing a program (or worse)
with bad (or malicious) input, we limit the requested
allocation of image data in a typesafe way.
Definition at line 495 of file pix1.c.
References Pix::informat, and Pix::refcount.
Referenced by pixCreateNoInit().
| PIX * pixCreateNoInit | ( | l_int32 | width, |
| l_int32 | height, | ||
| l_int32 | depth ) |
| [in] | width,height,depth |
Notes:
(1) Pad bits are set to avoid reading uninitialized data, because
some optimized routines read from pad bits.
(2) Initializing memory is very fast, so this optimization is
not used in the library.
Definition at line 344 of file pix1.c.
References pixCreateHeader(), pixDestroy(), and pixSetData().
Referenced by pixCreate(), and pixCreateTemplateNoInit().
| [in] | pixs |
Notes:
(1) Makes a Pix of the same size as the input Pix, with the
data array allocated and initialized to 0.
(2) Copies the other fields, including colormap if it exists.
Definition at line 380 of file pix1.c.
References Pix::data, Pix::h, pixCreateTemplateNoInit(), and Pix::wpl.
Referenced by pixCopy().
| [in] | pixs |
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.
(3) Pad bits are set to avoid reading uninitialized data, because
some optimized routines read from pad bits.
(4) Initializing memory is very fast, so this optimization is
not used in the library.
Definition at line 412 of file pix1.c.
References pixCopyColormap(), pixCopySpp(), pixCreateNoInit(), and pixGetDimensions().
Referenced by pixCreateTemplate().
| PIX * pixCreateWithCmap | ( | l_int32 | width, |
| l_int32 | height, | ||
| l_int32 | depth, | ||
| l_int32 | initcolor ) |
| [in] | width | |
| [in] | height | |
| [in] | depth | 2, 4 or 8 bpp |
| [in] | initcolor | L_SET_BLACK, L_SET_WHITE |
Notes:
(1) Creates a pix with a cmap, initialized to value 0.
(2) Initializes the pix black or white by adding that color
to the cmap at index 0.
Definition at line 451 of file pix1.c.
References L_SET_BLACK, pixCreate(), and pixSetColormap().
| void pixDestroy | ( | PIX ** | ppix | ) |
| [in,out] | ppix | will be set to null before returning |
Notes:
(1) Decrements the ref count and, if 0, destroys the pix.
(2) Always nulls the input ptr.
Definition at line 609 of file pix1.c.
References pixFree().
Referenced by pixCreateNoInit(), pixSwapAndDestroy(), and pixTransferAllData().
| l_ok pixDestroyColormap | ( | PIX * | pix | ) |
| [in] | pix |
Definition at line 1610 of file pix1.c.
References Pix::colormap.
Referenced by pixCopyColormap(), pixFree(), pixSetColormap(), and pixTransferAllData().
| l_uint32 * pixExtractData | ( | PIX * | pixs | ) |
| [in] | pix |
Notes:
(1) This extracts the pix image data for use in another context.
The caller still needs to use pixDestroy() on the input pix.
(2) If refcount == 1, the data is extracted and the
pix->data ptr is set to NULL.
(3) If refcount > 1, this simply returns a copy of the data,
using the pix allocator, and leaving the input pix unchanged.
Definition at line 1748 of file pix1.c.
References pixGetData(), pixSetData(), and Pix::refcount.
|
static |
| [in] | pix |
Notes:
(1) Decrements the ref count and, if 0, destroys the pix.
Definition at line 637 of file pix1.c.
References pixDestroyColormap(), pixGetData(), pixGetText(), and Pix::refcount.
Referenced by pixDestroy().
| l_int32 pixFreeAndSetData | ( | PIX * | pix, |
| l_uint32 * | data ) |
| [in] | pix | |
| [in] | data |
Notes:
(1) This frees the existing raster data in the pix and assigns data.
Definition at line 1664 of file pix1.c.
References Pix::data, and pixFreeData().
Referenced by pixResizeImageData().
| l_int32 pixFreeData | ( | PIX * | pix | ) |
| [in] | pix |
Notes:
(1) This frees the data and sets the pix data ptr to null.
It should be used before pixSetData() in the situation where
you want to free any existing data before doing
a subsequent assignment with pixSetData().
Definition at line 1716 of file pix1.c.
References Pix::data, and pixGetData().
Referenced by pixFreeAndSetData(), and pixTransferAllData().
| l_uint32 * pixGetData | ( | PIX * | pix | ) |
| [in] | pix |
Notes:
(1) This gives a new handle for the data. The data is still
owned by the pix, so do not call LEPT_FREE() on it.
(2) This cannot guarantee that the pix data returned will not
be changed, so pix cannot be declared const. And because
most imaging operations call this for access to the data,
this prevents them from declaring pix to be const, even if
they only use the data for inspection.
Definition at line 1643 of file pix1.c.
References Pix::data.
Referenced by pixExtractData(), pixFree(), pixFreeData(), pixGetLinePtrs(), and pixTransferAllData().
| l_ok pixGetDimensions | ( | const PIX * | pix, |
| l_int32 * | pw, | ||
| l_int32 * | ph, | ||
| l_int32 * | pd ) |
| [in] | pix | |
| [out] | pw,ph,pd | [optional] each can be null |
Definition at line 1075 of file pix1.c.
References Pix::d, Pix::h, and Pix::w.
Referenced by pixCreateTemplateNoInit(), pixMaxAspectRatio(), and pixResizeImageData().
| void ** pixGetLinePtrs | ( | PIX * | pix, |
| l_int32 * | psize ) |
| [in] | pix | |
| [out] | psize | [optional] array size, which is the pix height |
Notes:
(1) This is intended to be used for fast random pixel access.
For example, for an 8 bpp image,
val = GET_DATA_BYTE(lines8[i], j);
is equivalent to, but much faster than,
pixGetPixel(pix, j, i, &val);
(2) How much faster? For 1 bpp, it's from 6 to 10x faster.
For 8 bpp, it's an amazing 30x faster. So if you are
doing random access over a substantial part of the image,
use this line ptr array.
(3) When random access is used in conjunction with a stack,
queue or heap, the overall computation time depends on
the operations performed on each struct that is popped
or pushed, and whether we are using a priority queue (O(logn))
or a queue or stack (O(1)). For example, for maze search,
the overall ratio of time for line ptrs vs. pixGet/Set* is
Maze type Type Time ratio
binary queue 0.4
gray heap (priority queue) 0.6
(4) Because this returns a void** and the accessors take void*,
the compiler cannot check the pointer types. It is
strongly recommended that you adopt a naming scheme for
the returned ptr arrays that indicates the pixel depth.
(This follows the original intent of Simonyi's "Hungarian"
application notation, where naming is used proactively
to make errors visibly obvious.) By doing this, you can
tell by inspection if the correct accessor is used.
For example, for an 8 bpp pixg:
void **lineg8 = pixGetLinePtrs(pixg, NULL);
val = GET_DATA_BYTE(lineg8[i], j); // fast access; BYTE, 8
...
LEPT_FREE(lineg8); // don't forget this
(5) These are convenient for accessing bytes sequentially in an
8 bpp grayscale image. People who write image processing code
on 8 bpp images are accustomed to grabbing pixels directly out
of the raster array. Note that for little endians, you first
need to reverse the byte order in each 32-bit word.
Here's a typical usage pattern:
pixEndianByteSwap(pix); // always safe; no-op on big-endians
l_uint8 **lineptrs = (l_uint8 **)pixGetLinePtrs(pix, NULL);
pixGetDimensions(pix, &w, &h, NULL);
for (i = 0; i < h; i++) {
l_uint8 *line = lineptrs[i];
for (j = 0; j < w; j++) {
val = line[j];
...
}
}
pixEndianByteSwap(pix); // restore big-endian order
LEPT_FREE(lineptrs);
This can be done even more simply as follows:
l_uint8 **lineptrs = pixSetupByteProcessing(pix, &w, &h);
for (i = 0; i < h; i++) {
l_uint8 *line = lineptrs[i];
for (j = 0; j < w; j++) {
val = line[j];
...
}
}
pixCleanupByteProcessing(pix, lineptrs);
Definition at line 1845 of file pix1.c.
References pixGetData().
| l_ok pixGetResolution | ( | const PIX * | pix, |
| l_int32 * | pxres, | ||
| l_int32 * | pyres ) |
| char * pixGetText | ( | PIX * | pix | ) |
| [in] | pix |
Notes:
(1) The text string belongs to the pix:
* the caller must NOT free it
* it must not be used after the pix is destroyed
Definition at line 1409 of file pix1.c.
References Pix::text.
Referenced by pixAddText(), pixFree(), pixGetTextCompNew(), and pixTransferAllData().
| l_uint8 * pixGetTextCompNew | ( | PIX * | pix, |
| size_t * | psize ) |
| [in] | pix | |
| [out] | psize | this number of bytes of returned binary data |
Notes:
(1) The ascii string in the text field of the input pix was
previously stored there using pixSetTextCompNew().
(2) This retrieves the string and performs ascii85 decoding
followed by decompression on it. The returned binary data
is owned by the caller and must be freed.
Definition at line 1506 of file pix1.c.
References pixGetText().
| l_ok pixMaxAspectRatio | ( | PIX * | pixs, |
| l_float32 * | pratio ) |
| [in] | pixs | 32 bpp rgb |
| [out] | pratio | max aspect ratio, >= 1.0; -1.0 on error |
Definition at line 1905 of file pix1.c.
References pixGetDimensions().
| l_ok pixPrintStreamInfo | ( | FILE * | fp, |
| const PIX * | pix, | ||
| const char * | text ) |
| [in] | fp | file stream |
| [in] | pix | |
| [in] | text | [optional] identifying string; can be null |
Definition at line 1940 of file pix1.c.
References Pix::colormap, Pix::data, Pix::refcount, and Pix::text.
| [in] | pixd | gets new uninitialized buffer for image data |
| [in] | pixs | determines the size of the buffer; not changed |
Notes:
(1) If the sizes of data in pixs and pixd are unequal, this
frees the existing image data in pixd and allocates
an uninitialized buffer that will hold the required amount
of image data in pixs. The image data from pixs is not
copied into the new buffer.
(2) On failure to allocate, pixd is unchanged.
Definition at line 751 of file pix1.c.
References pixFreeAndSetData(), pixGetDimensions(), and pixSizesEqual().
Referenced by pixCopy(), and pixTransferAllData().
| l_int32 pixScaleResolution | ( | PIX * | pix, |
| l_float32 | xscale, | ||
| l_float32 | yscale ) |
| [in] | pix | |
| [in] | colormap | optional; can be null. |
Notes:
(1) If colormap is not defined, this is a no-op.
(2) This destroys any existing colormap before assigning the
new colormap to pix.
(3) If the colormap is not valid, this returns 1. The caller
should check if there is a possibility that the pix and
colormap depths differ.
(4) This does not do the work of checking pixs for a pixel value
that is out of bounds for the colormap -- that only needs to
be done when reading and writing with an I/O library like
png and gif.
(5) Because colormaps are not ref counted, the new colormap
must not belong to any other pix.
Definition at line 1583 of file pix1.c.
References Pix::colormap, and pixDestroyColormap().
Referenced by pixCopyColormap(), and pixCreateWithCmap().
| l_int32 pixSetData | ( | PIX * | pix, |
| l_uint32 * | data ) |
| [in] | pix | |
| [in] | data |
Notes:
(1) This does not free any existing data. To free existing
data, use pixFreeAndSetData() instead.
Definition at line 1690 of file pix1.c.
References Pix::data.
Referenced by pixCreateNoInit(), pixExtractData(), and pixTransferAllData().
| l_ok pixSetDimensions | ( | PIX * | pix, |
| l_int32 | w, | ||
| l_int32 | h, | ||
| l_int32 | d ) |
| [in] | pix | |
| [in] | w,h,d | use 0 to skip the setting for any of these |
| l_ok pixSetResolution | ( | PIX * | pix, |
| l_int32 | xres, | ||
| l_int32 | yres ) |
| l_ok pixSetText | ( | PIX * | pix, |
| const char * | textstring ) |
| [in] | pix | |
| [in] | textstring | can be null |
Notes:
(1) This removes any existing textstring and puts a copy of
the input textstring there.
Definition at line 1431 of file pix1.c.
References Pix::text.
Referenced by pixTransferAllData().
| l_ok pixSetTextCompNew | ( | PIX * | pix, |
| const l_uint8 * | data, | ||
| size_t | size ) |
| [in] | pix | |
| [in] | data | binary data |
| [in] | size | number of bytes of binary data |
Notes:
(1) This receives binary data and performs compression and ascii85
encoding on it. The ascii result is stored in the input pix,
replacing any string that may be there.
(2) The input data can be reconstructed using pixGetTextCompNew().
Definition at line 1535 of file pix1.c.
References Pix::text.
| [in] | pix1,pix2 |
Definition at line 1879 of file pix1.c.
Referenced by pixResizeImageData().
| [out] | ppixd | [optional] input pixd can be null, and it must be different from pixs |
| [in,out] | ppixs | will be nulled after the swap |
Notes:
(1) Simple operation to change the handle name safely.
After this operation, the original image in pixd has
been destroyed, pixd points to what was pixs, and
the input pixs ptr has been nulled.
(2) This works safely whether or not pixs and pixd are cloned.
If pixs is cloned, the other handles still point to
the original image, with the ref count reduced by 1.
(3) Usage example:
Pix *pix1 = pixRead("...");
Pix *pix2 = function(pix1, ...);
pixSwapAndDestroy(&pix1, &pix2);
pixDestroy(&pix1); // holds what was in pix2
Definition pix_internal.h:181
Example with clones ([] shows ref count of image generated
by the function):
Pix *pixs = pixRead("...");
Pix *pix1 = pixClone(pixs);
Pix *pix2 = function(pix1, ...); [1]
Pix *pix3 = pixClone(pix2); [1] --> [2]
pixSwapAndDestroy(&pix1, &pix2);
pixDestroy(&pixs); // still holds read image
pixDestroy(&pix1); // holds what was in pix2 [2] --> [1]
pixDestroy(&pix3); // holds what was in pix2 [1] --> [0]
Definition at line 969 of file pix1.c.
References pixClone(), and pixDestroy().
| [in] | pixd | must be different from pixs |
| [in,out] | ppixs | will be nulled if refcount goes to 0 |
| [in] | copytext | 1 to copy the text field; 0 to skip |
| [in] | copyformat | 1 to copy the informat field; 0 to skip |
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:
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.
Definition at line 880 of file pix1.c.
References Pix::colormap, Pix::data, pixCopyColormap(), pixCopyDimensions(), pixCopySpp(), pixDestroy(), pixDestroyColormap(), pixFreeData(), pixGetData(), pixGetText(), pixResizeImageData(), pixSetData(), pixSetText(), and Pix::refcount.
| void setPixMemoryManager | ( | alloc_fn | allocator, |
| dealloc_fn | deallocator ) |
| [in] | allocator | [optional] use NULL to skip |
| [in] | deallocator | [optional] use NULL to skip |
Notes:
(1) Use this to change the alloc and/or dealloc functions;
e.g., setPixMemoryManager(my_malloc, my_free).
(2) The C99 standard (section 6.7.5.3, par. 8) says:
A declaration of a parameter as "function returning type"
shall be adjusted to "pointer to function returning type"
so that it can be in either of these two forms:
(a) type (function-ptr(type, ...))
(b) type ((*function-ptr)(type, ...))
because form (a) is implicitly converted to form (b), as in the
definition of struct PixMemoryManager above. So, for example,
we should be able to declare either of these:
(a) void *(allocator(size_t))
(b) void *((*allocator)(size_t))
However, MSVC++ only accepts the second version.
Definition at line 296 of file pix1.c.
References pix_mem_manager.
|
static |
Default Pix memory manager
Definition at line 236 of file pix1.c.
Referenced by setPixMemoryManager().
1.12.0