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* Renamed read_vpag_chunk_callback() function to png_user_chunk_callb…
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…ack()

  in coders/png.c
* Implemented a private PNG caNv (canvas) chunk for remembering the
  original dimensions and offsets when an image is cropped.  Previously
  we used the oFFs and vpAg chunks for this purpose, but this had potential
  conflicts with other applications that also use the oFFs chunk.
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@glennrp
glennrp committed Jan 22, 2017
1 parent ad73e6c commit a9e228f
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8 changes: 8 additions & 0 deletions ChangeLog
View file
Original file line number Diff line number Diff line change
@@ -1,3 +1,11 @@
2017-01-22 7.0.4-6 Glenn Randers-Pehrson <glennrp@image...>
* Renamed read_vpag_chunk_callback() function to png_user_chunk_callback()
in coders/png.c
* Implemented a private PNG caNv (canvas) chunk for remembering the
original dimensions and offsets when an image is cropped. Previously
we used the oFFs and vpAg chunks for this purpose, but this had potential
conflicts with other applications that also use the oFFs chunk.

2017-01-22 7.0.4-6 Dirk Lemstra <dirk@lem.....org>
* Replaced CoderSeekableStreamFlag with CoderDecoderSeekableStreamFlag and
CoderEncoderSeekableStreamFlag.
Expand Down
188 changes: 142 additions & 46 deletions coders/png.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -549,6 +549,7 @@ static const png_byte mng_SEEK[5]={ 83, 69, 69, 75, (png_byte) '\0'};
static const png_byte mng_SHOW[5]={ 83, 72, 79, 87, (png_byte) '\0'};
static const png_byte mng_TERM[5]={ 84, 69, 82, 77, (png_byte) '\0'};
static const png_byte mng_bKGD[5]={ 98, 75, 71, 68, (png_byte) '\0'};
static const png_byte mng_caNv[5]={ 99, 97, 78, 118, (png_byte) '\0'};
static const png_byte mng_cHRM[5]={ 99, 72, 82, 77, (png_byte) '\0'};
static const png_byte mng_gAMA[5]={103, 65, 77, 65, (png_byte) '\0'};
static const png_byte mng_iCCP[5]={105, 67, 67, 80, (png_byte) '\0'};
Expand Down Expand Up @@ -811,6 +812,7 @@ typedef struct _MngInfo
ping_exclude_tEXt,
ping_exclude_tRNS,
ping_exclude_vpAg,
ping_exclude_caNv,
ping_exclude_zCCP, /* hex-encoded iCCP */
ping_exclude_zTXt,
ping_preserve_colormap,
Expand Down Expand Up @@ -1806,7 +1808,7 @@ Magick_png_read_raw_profile(png_struct *ping,Image *image,
}

#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
static int read_vpag_chunk_callback(png_struct *ping, png_unknown_chunkp chunk)
static int read_user_chunk_callback(png_struct *ping, png_unknown_chunkp chunk)
{
Image
*image;
Expand All @@ -1821,36 +1823,68 @@ static int read_vpag_chunk_callback(png_struct *ping, png_unknown_chunkp chunk)
*/

LogMagickEvent(CoderEvent,GetMagickModule(),
" read_vpag_chunk: found %c%c%c%c chunk",
" read_user_chunk: found %c%c%c%c chunk",
chunk->name[0],chunk->name[1],chunk->name[2],chunk->name[3]);

if (chunk->name[0] != 118 || chunk->name[1] != 112 ||
chunk->name[2] != 65 ||chunk-> name[3] != 103)
return(0); /* Did not recognize */
/* vpAg (deprecated, replaced by caNv) */
if (chunk->name[0] == 118 &&
chunk->name[1] == 112 &&
chunk->name[2] == 65 &&
chunk->name[3] == 103)
{
/* recognized vpAg */

if (chunk->size != 9)
return(-1); /* Error return */

if (chunk->data[8] != 0)
return(0); /* ImageMagick requires pixel units */

image=(Image *) png_get_user_chunk_ptr(ping);

image->page.width=(size_t) ((chunk->data[0] << 24) |
(chunk->data[1] << 16) | (chunk->data[2] << 8) | chunk->data[3]);

/* recognized vpAg */
image->page.height=(size_t) ((chunk->data[4] << 24) |
(chunk->data[5] << 16) | (chunk->data[6] << 8) | chunk->data[7]);

return(1);
}

/* caNv */
if (chunk->name[0] == 99 &&
chunk->name[1] == 97 &&
chunk->name[2] == 78 &&
chunk->name[3] == 118)
{
/* recognized caNv */

if (chunk->size != 9)
return(-1); /* Error return */
if (chunk->size != 16)
return(-1); /* Error return */

if (chunk->data[8] != 0)
return(0); /* ImageMagick requires pixel units */
image=(Image *) png_get_user_chunk_ptr(ping);

image=(Image *) png_get_user_chunk_ptr(ping);
image->page.width=(size_t) ((chunk->data[0] << 24) |
(chunk->data[1] << 16) | (chunk->data[2] << 8) | chunk->data[3]);

image->page.width=(size_t) ((chunk->data[0] << 24) |
(chunk->data[1] << 16) | (chunk->data[2] << 8) | chunk->data[3]);
image->page.height=(size_t) ((chunk->data[4] << 24) |
(chunk->data[5] << 16) | (chunk->data[6] << 8) | chunk->data[7]);

image->page.height=(size_t) ((chunk->data[4] << 24) |
(chunk->data[5] << 16) | (chunk->data[6] << 8) | chunk->data[7]);
image->page.x=(size_t) ((chunk->data[8] << 24) |
(chunk->data[9] << 16) | (chunk->data[10] << 8) | chunk->data[11]);

/* Return one of the following: */
/* return(-n); chunk had an error */
/* return(0); did not recognize */
/* return(n); success */
image->page.y=(size_t) ((chunk->data[12] << 24) |
(chunk->data[13] << 16) | (chunk->data[14] << 8) | chunk->data[15]);

return(1);
/* Return one of the following: */
/* return(-n); chunk had an error */
/* return(0); did not recognize */
/* return(n); success */

return(1);
}

return(0); /* Did not recognize */
}
#endif

Expand Down Expand Up @@ -2263,22 +2297,23 @@ static Image *ReadOnePNGImage(MngInfo *mng_info,
#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
else
{
png_set_keep_unknown_chunks(ping, 1, mng_iCCP, 1);
png_set_keep_unknown_chunks(ping, 1, (png_bytep) mng_iCCP, 1);
}
#endif
}
#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
/* Ignore unused chunks and all unknown chunks except for vpAg */
#if PNG_LIBPNG_VER < 10700 /* Avoid libpng16 warning */
/* Ignore unused chunks and all unknown chunks except for caNv and vpAg */
# if PNG_LIBPNG_VER < 10700 /* Avoid libpng16 warning */
png_set_keep_unknown_chunks(ping, 2, NULL, 0);
#else
# else
png_set_keep_unknown_chunks(ping, 1, NULL, 0);
#endif
png_set_keep_unknown_chunks(ping, 2, mng_vpAg, 1);
# endif
png_set_keep_unknown_chunks(ping, 2, (png_bytep) mng_caNv, 1);
png_set_keep_unknown_chunks(ping, 2, (png_bytep) mng_vpAg, 1);
png_set_keep_unknown_chunks(ping, 1, unused_chunks,
(int)sizeof(unused_chunks)/5);
/* Callback for other unknown chunks */
png_set_read_user_chunk_fn(ping, image, read_vpag_chunk_callback);
png_set_read_user_chunk_fn(ping, image, read_user_chunk_callback);
#endif

#ifdef PNG_SET_USER_LIMITS_SUPPORTED
Expand Down Expand Up @@ -3823,6 +3858,7 @@ static Image *ReadOnePNGImage(MngInfo *mng_info,
exception);
}

/* cHRM chunk: */
if (ping_found_cHRM != MagickFalse)
{
(void) FormatLocaleString(msg,MagickPathExtent,"%s",
Expand All @@ -3831,6 +3867,7 @@ static Image *ReadOnePNGImage(MngInfo *mng_info,
exception);
}

/* bKGD chunk: */
if (png_get_valid(ping,ping_info,PNG_INFO_bKGD))
{
(void) FormatLocaleString(msg,MagickPathExtent,"%s",
Expand All @@ -3843,6 +3880,7 @@ static Image *ReadOnePNGImage(MngInfo *mng_info,
"chunk was found");

#if defined(PNG_iCCP_SUPPORTED)
/* iCCP chunk: */
if (ping_found_iCCP != MagickFalse)
(void) SetImageProperty(image,"png:iCCP",msg,
exception);
Expand All @@ -3853,6 +3891,7 @@ static Image *ReadOnePNGImage(MngInfo *mng_info,
exception);

#if defined(PNG_sRGB_SUPPORTED)
/* sRGB chunk: */
if (ping_found_sRGB != MagickFalse)
{
(void) FormatLocaleString(msg,MagickPathExtent,
Expand All @@ -3864,6 +3903,7 @@ static Image *ReadOnePNGImage(MngInfo *mng_info,
}
#endif

/* gAMA chunk: */
if (ping_found_gAMA != MagickFalse)
{
(void) FormatLocaleString(msg,MagickPathExtent,
Expand All @@ -3874,6 +3914,7 @@ static Image *ReadOnePNGImage(MngInfo *mng_info,
}

#if defined(PNG_pHYs_SUPPORTED)
/* pHYs chunk: */
if (png_get_valid(ping,ping_info,PNG_INFO_pHYs))
{
(void) FormatLocaleString(msg,MagickPathExtent,
Expand All @@ -3885,6 +3926,7 @@ static Image *ReadOnePNGImage(MngInfo *mng_info,
#endif

#if defined(PNG_oFFs_SUPPORTED)
/* oFFs chunk: */
if (png_get_valid(ping,ping_info,PNG_INFO_oFFs))
{
(void) FormatLocaleString(msg,MagickPathExtent,"x_off=%.20g, y_off=%.20g",
Expand All @@ -3898,6 +3940,20 @@ static Image *ReadOnePNGImage(MngInfo *mng_info,
read_tIME_chunk(image,ping,end_info,exception);
#endif

/* caNv chunk: */
if ((image->page.width != 0 && image->page.width != image->columns) ||
(image->page.height != 0 && image->page.height != image->rows) ||
(image->page.x != 0 || image->page.y != 0))
{
(void) FormatLocaleString(msg,MagickPathExtent,
"width=%.20g, height=%.20g, x_offset=%.20g, y_offset=%.20g",
(double) image->page.width,(double) image->page.height,
(double) image->page.x,(double) image->page.y);
(void) SetImageProperty(image,"png:caNv",msg,
exception);
}

/* vpAg chunk: */
if ((image->page.width != 0 && image->page.width != image->columns) ||
(image->page.height != 0 && image->page.height != image->rows))
{
Expand Down Expand Up @@ -7414,7 +7470,7 @@ ModuleExport size_t RegisterPNGImage(void)
#endif

entry=AcquireMagickInfo("PNG","MNG","Multiple-image Network Graphics");
entry->flags|=CoderDecoderSeekableStreamFlag; /* To do: eliminate this. */
entry->flags|=CoderSeekableStreamFlag; /* To do: eliminate this. */

#if defined(MAGICKCORE_PNG_DELEGATE)
entry->decoder=(DecodeImageHandler *) ReadMNGImage;
Expand Down Expand Up @@ -7906,7 +7962,8 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,

int
num_passes,
pass;
pass,
ping_wrote_caNv;

png_byte
ping_trans_alpha[256];
Expand Down Expand Up @@ -7961,6 +8018,7 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
ping_exclude_tIME,
/* ping_exclude_tRNS, */
ping_exclude_vpAg,
ping_exclude_caNv,
ping_exclude_zCCP, /* hex-encoded iCCP */
ping_exclude_zTXt,

Expand Down Expand Up @@ -8105,6 +8163,7 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
ping_have_tRNS=MagickFalse;

ping_exclude_bKGD=mng_info->ping_exclude_bKGD;
ping_exclude_caNv=mng_info->ping_exclude_caNv;
ping_exclude_cHRM=mng_info->ping_exclude_cHRM;
ping_exclude_date=mng_info->ping_exclude_date;
/* ping_exclude_EXIF=mng_info->ping_exclude_EXIF; */
Expand Down Expand Up @@ -10708,22 +10767,6 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
}
}

#if defined(PNG_oFFs_SUPPORTED)
if (ping_exclude_oFFs == MagickFalse)
{
if (image->page.x || image->page.y)
{
png_set_oFFs(ping,ping_info,(png_int_32) image->page.x,
(png_int_32) image->page.y, 0);

if (logging != MagickFalse)
(void) LogMagickEvent(CoderEvent,GetMagickModule(),
" Setting up oFFs chunk with x=%d, y=%d, units=0",
(int) image->page.x, (int) image->page.y);
}
}
#endif

#if defined(PNG_tIME_SUPPORTED)
if (ping_exclude_tIME == MagickFalse)
{
Expand Down Expand Up @@ -10802,7 +10845,49 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
/* write any PNG-chunk-m profiles */
(void) Magick_png_write_chunk_from_profile(image,"PNG-chunk-m",logging);

if (ping_exclude_vpAg == MagickFalse)
ping_wrote_caNv = MagickFalse;

/* write caNv chunk */
if (ping_exclude_caNv == MagickFalse)
{
if ((image->page.width != 0 && image->page.width != image->columns) ||
(image->page.height != 0 && image->page.height != image->rows) ||
image->page.x != 0 || image->page.y != 0)
{
unsigned char
chunk[20];

(void) WriteBlobMSBULong(image,16L); /* data length=8 */
PNGType(chunk,mng_caNv);
LogPNGChunk(logging,mng_caNv,16L);
PNGLong(chunk+4,(png_uint_32) image->page.width);
PNGLong(chunk+8,(png_uint_32) image->page.height);
PNGsLong(chunk+12,(png_int_32) image->page.x);
PNGsLong(chunk+16,(png_int_32) image->page.y);
(void) WriteBlob(image,20,chunk);
(void) WriteBlobMSBULong(image,crc32(0,chunk,20));
ping_wrote_caNv = MagickTrue;
}
}

#if defined(PNG_oFFs_SUPPORTED)
if (ping_exclude_oFFs == MagickFalse && ping_wrote_caNv == MagickFalse)
{
if (image->page.x || image->page.y)
{
png_set_oFFs(ping,ping_info,(png_int_32) image->page.x,
(png_int_32) image->page.y, 0);

if (logging != MagickFalse)
(void) LogMagickEvent(CoderEvent,GetMagickModule(),
" Setting up oFFs chunk with x=%d, y=%d, units=0",
(int) image->page.x, (int) image->page.y);
}
}
#endif

/* write vpAg chunk (deprecated, replaced by caNv) */
if (ping_exclude_vpAg == MagickFalse && ping_wrote_caNv == MagickFalse)
{
if ((image->page.width != 0 && image->page.width != image->columns) ||
(image->page.height != 0 && image->page.height != image->rows))
Expand Down Expand Up @@ -11809,6 +11894,7 @@ static MagickBooleanType WritePNGImage(const ImageInfo *image_info,
*/

mng_info->ping_exclude_bKGD=MagickFalse;
mng_info->ping_exclude_caNv=MagickFalse;
mng_info->ping_exclude_cHRM=MagickFalse;
mng_info->ping_exclude_date=MagickFalse;
mng_info->ping_exclude_EXIF=MagickFalse; /* hex-encoded EXIF in zTXt */
Expand Down Expand Up @@ -12016,6 +12102,7 @@ static MagickBooleanType WritePNGImage(const ImageInfo *image_info,
if (IsOptionMember("all",value) != MagickFalse)
{
mng_info->ping_exclude_bKGD=excluding;
mng_info->ping_exclude_caNv=excluding;
mng_info->ping_exclude_cHRM=excluding;
mng_info->ping_exclude_date=excluding;
mng_info->ping_exclude_EXIF=excluding;
Expand All @@ -12037,6 +12124,8 @@ static MagickBooleanType WritePNGImage(const ImageInfo *image_info,
{
mng_info->ping_exclude_bKGD=excluding != MagickFalse ? MagickFalse :
MagickTrue;
mng_info->ping_exclude_caNv=excluding != MagickFalse ? MagickFalse :
MagickTrue;
mng_info->ping_exclude_cHRM=excluding != MagickFalse ? MagickFalse :
MagickTrue;
mng_info->ping_exclude_date=excluding != MagickFalse ? MagickFalse :
Expand Down Expand Up @@ -12071,6 +12160,9 @@ static MagickBooleanType WritePNGImage(const ImageInfo *image_info,
if (IsOptionMember("bkgd",value) != MagickFalse)
mng_info->ping_exclude_bKGD=excluding;

if (IsOptionMember("caNv",value) != MagickFalse)
mng_info->ping_exclude_caNv=excluding;

if (IsOptionMember("chrm",value) != MagickFalse)
mng_info->ping_exclude_cHRM=excluding;

Expand Down Expand Up @@ -12126,6 +12218,9 @@ static MagickBooleanType WritePNGImage(const ImageInfo *image_info,
if (mng_info->ping_exclude_bKGD != MagickFalse)
(void) LogMagickEvent(CoderEvent,GetMagickModule(),
" bKGD");
if (mng_info->ping_exclude_caNv != MagickFalse)
(void) LogMagickEvent(CoderEvent,GetMagickModule(),
" caNv");
if (mng_info->ping_exclude_cHRM != MagickFalse)
(void) LogMagickEvent(CoderEvent,GetMagickModule(),
" cHRM");
Expand Down Expand Up @@ -13652,6 +13747,7 @@ static MagickBooleanType WriteMNGImage(const ImageInfo *image_info,Image *image,

/* We don't want any ancillary chunks written */
mng_info->ping_exclude_bKGD=MagickTrue;
mng_info->ping_exclude_caNv=MagickTrue;
mng_info->ping_exclude_cHRM=MagickTrue;
mng_info->ping_exclude_date=MagickTrue;
mng_info->ping_exclude_EXIF=MagickTrue;
Expand Down

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