Initial PNG support and test files.

pdfio-content.c

@@ -44,7 +44,7 @@ const double	pdfioSRGBWhitePoint[3] = { 0.9505, 1.0, 1.0890 };
 #define _PDFIO_PNG_CHUNK_gAMA	0x67414d41	// Gamma correction
 #define _PDFIO_PNG_CHUNK_tRNS	0x74524e53	// Transparency information
 
-#define _PDIFO_PNG_TYPE_GRAY	0	// Grayscale
+#define _PDFIO_PNG_TYPE_GRAY	0	// Grayscale
 #define _PDFIO_PNG_TYPE_RGB	2	// RGB
 #define _PDFIO_PNG_TYPE_INDEXED	3	// Indexed
 #define _PDFIO_PNG_TYPE_GRAYA	4	// Grayscale + alpha
@@ -64,9 +64,62 @@ typedef pdfio_obj_t *(*_pdfio_image_func_t)(pdfio_dict_t *dict, int fd);
 
 static pdfio_obj_t	*copy_jpeg(pdfio_dict_t *dict, int fd);
 static pdfio_obj_t	*copy_png(pdfio_dict_t *dict, int fd);
+static unsigned		update_png_crc(unsigned crc, const unsigned char *buffer, size_t length);
 static bool		write_string(pdfio_stream_t *st, const char *s, bool *newline);
 
 
+//
+// Local globals...
+//
+
+static unsigned png_crc_table[256] =	// CRC-32 table for PNG files
+{
+  0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
+  0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
+  0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
+  0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
+  0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
+  0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
+  0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
+  0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
+  0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
+  0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
+  0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
+  0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
+  0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
+  0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
+  0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
+  0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
+  0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
+  0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
+  0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
+  0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+  0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
+  0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
+  0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
+  0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
+  0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
+  0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
+  0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
+  0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
+  0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
+  0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
+  0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
+  0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
+  0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
+  0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
+  0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
+  0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
+  0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
+  0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
+  0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
+  0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+  0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
+  0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
+  0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
+};
+
+
 //
 // 'pdfioArrayCreateCalibratedColorFromMatrix()' - Create a calibrated color space array using a CIE XYZ transform matrix.
 //
@@ -260,7 +313,7 @@ pdfio_array_t *				// O - Color array
 pdfioArrayCreateIndexedColor(
     pdfio_file_t        *pdf,		// I - PDF file
     size_t              num_colors,	// I - Number of colors
-    const unsigned char colors[][3])	// I - RGB values for colors
+    const unsigned char *colors)	// I - RGB values for colors
 {
   pdfio_array_t	*indexed_color;		// Color array
 
@@ -276,7 +329,7 @@ pdfioArrayCreateIndexedColor(
   pdfioArrayAppendName(indexed_color, "Indexed");
   pdfioArrayAppendName(indexed_color, "DeviceRGB");
   pdfioArrayAppendNumber(indexed_color, num_colors - 1);
-  pdfioArrayAppendBinary(indexed_color, colors[0], num_colors * 3);
+  pdfioArrayAppendBinary(indexed_color, colors, num_colors * 3);
 
   return (indexed_color);
 }
@@ -1581,12 +1634,14 @@ copy_png(pdfio_dict_t *dict,		// I - Dictionary
          int          fd)		// I - File descriptor
 {
   pdfio_obj_t	*obj = NULL;		// Object
-  pdfio_stream_t *st = NULL;		// Stream for JPEG data
+  pdfio_stream_t *st = NULL;		// Stream for PNG data
+  pdfio_dict_t	*decode = NULL;		// Parameters for PNG decode
   ssize_t	bytes;			// Bytes read
   unsigned char	buffer[16384];		// Read buffer
   unsigned	length,			// Length
 		type,			// Chunk code
 		crc,			// CRC-32
+		temp,			// Temporary value
 		width = 0,		// Width
 		height = 0;		// Height
   unsigned char	bit_depth = 0,		// Bit depth
@@ -1603,21 +1658,134 @@ copy_png(pdfio_dict_t *dict,		// I - Dictionary
     // Get the chunk length and type values...
     length = (unsigned)((buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3]);
     type   = (unsigned)((buffer[4] << 24) | (buffer[5] << 16) | (buffer[6] << 8) | buffer[7]);
+    crc    = update_png_crc(0xffffffff, buffer, 8);
 
     switch (type)
     {
       case _PDFIO_PNG_CHUNK_IDAT : // Image data
+          if (!width || !height)
+          {
+            _pdfioFileError(dict->pdf, "Image data seen in PNG file before header.");
+            return (NULL);
+	  }
+
+          if (!st)
+          {
+	    obj = pdfioFileCreateObject(dict->pdf, dict);
+
+	    if ((st = pdfioObjCreateStream(obj, PDFIO_FILTER_NONE)) == NULL)
+	    {
+	      pdfioObjClose(obj);
+	      return (NULL);
+	    }
+          }
+
+          while (length > 0)
+          {
+            if (length > sizeof(buffer))
+              bytes = (ssize_t)sizeof(buffer);
+	    else
+	      bytes = (ssize_t)length;
+
+            if ((bytes = read(fd, buffer, (size_t)bytes)) <= 0)
+	    {
+	      pdfioStreamClose(st);
+	      _pdfioFileError(dict->pdf, "Early end-of-file in image file.");
+	      return (NULL);
+	    }
+
+            crc = update_png_crc(crc, buffer, (size_t)bytes);
+
+            if (!pdfioStreamWrite(st, buffer, (size_t)bytes))
+            {
+	      pdfioStreamClose(st);
+	      _pdfioFileError(dict->pdf, "Unable to copy image data.");
+	      return (NULL);
+            }
+
+            length -= bytes;
+          }
           break;
 
       case _PDFIO_PNG_CHUNK_IEND : // Image end
+          if (st)
+          {
+            pdfioStreamClose(st);
+            return (obj);
+          }
           break;
 
       case _PDFIO_PNG_CHUNK_IHDR : // Image header
+          if (st)
+          {
+	    pdfioStreamClose(st);
+	    _pdfioFileError(dict->pdf, "Unexpected image header.");
+	    return (NULL);
+          }
+
+          if (length != 13)
+          {
+	    _pdfioFileError(dict->pdf, "Early end-of-file in image file.");
+	    return (NULL);
+          }
+
+          if (read(fd, buffer, length) != length)
+          {
+	    _pdfioFileError(dict->pdf, "Early end-of-file in image file.");
+	    return (NULL);
+          }
+
+	  crc        = update_png_crc(crc, buffer, length);
+	  width      = (unsigned)((buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3]);
+	  height     = (unsigned)((buffer[4] << 24) | (buffer[5] << 16) | (buffer[6] << 8) | buffer[7]);
+	  bit_depth  = buffer[8];
+	  color_type = buffer[9];
+
+	  if (width == 0 || height == 0 || (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 && bit_depth != 8 && bit_depth != 16) || (color_type != _PDFIO_PNG_TYPE_GRAY && color_type != _PDFIO_PNG_TYPE_RGB && color_type != _PDFIO_PNG_TYPE_INDEXED) || buffer[10] || buffer[11] || buffer[12])
+	  {
+	    _pdfioFileError(dict->pdf, "Unsupported PNG image.");
+	    return (NULL);
+	  }
+
+	  pdfioDictSetNumber(dict, "Width", width);
+	  pdfioDictSetNumber(dict, "Height", height);
+	  pdfioDictSetNumber(dict, "BitsPerComponent", bit_depth);
+	  if (color_type == _PDFIO_PNG_TYPE_GRAY)
+	    pdfioDictSetArray(dict, "ColorSpace", pdfioArrayCreateCalibratedColorFromMatrix(dict->pdf, 1, pdfioSRGBGamma, NULL, NULL));
+	  else if (color_type == _PDFIO_PNG_TYPE_RGB)
+	    pdfioDictSetArray(dict, "ColorSpace", pdfioArrayCreateCalibratedColorFromMatrix(dict->pdf, 3, pdfioSRGBGamma, pdfioSRGBMatrix, pdfioSRGBWhitePoint));
+	  pdfioDictSetName(dict, "Filter", "FlateDecode");
+
+	  if ((decode = pdfioDictCreate(dict->pdf)) == NULL)
+	    return (NULL);
+
+	  pdfioDictSetNumber(decode, "BitsPerComponent", bit_depth);
+	  pdfioDictSetNumber(decode, "Colors", color_type == _PDFIO_PNG_TYPE_RGB ? 3 : 1);
+	  pdfioDictSetNumber(decode, "Columns", width);
+	  pdfioDictSetNumber(decode, "Predictor", _PDFIO_PREDICTOR_PNG_AUTO);
+	  pdfioDictSetDict(dict, "DecodeParms", decode);
           break;
 
       case _PDFIO_PNG_CHUNK_PLTE : // Palette
+          if (length == 0 || (length % 3) != 0 || length > 768)
+          {
+	    pdfioStreamClose(st);
+	    _pdfioFileError(dict->pdf, "Invalid color palette.");
+	    return (NULL);
+          }
+
+          if (read(fd, buffer, length) != length)
+          {
+	    _pdfioFileError(dict->pdf, "Early end-of-file in image file.");
+	    return (NULL);
+          }
+
+	  crc = update_png_crc(crc, buffer, length);
+
+          pdfioDictSetArray(dict, "ColorSpace", pdfioArrayCreateIndexedColor(dict->pdf, length / 3, buffer));
           break;
 
+#if 0
       case _PDFIO_PNG_CHUNK_cHRM : // Cromacities and white point
           break;
 
@@ -1626,16 +1794,73 @@ copy_png(pdfio_dict_t *dict,		// I - Dictionary
 
       case _PDFIO_PNG_CHUNK_tRNS : // Transparency information
           break;
+#endif // 0
 
-      default :
+      default : // Something else
+          while (length > 0)
+          {
+            if (length > sizeof(buffer))
+              bytes = (ssize_t)sizeof(buffer);
+	    else
+	      bytes = (ssize_t)length;
+
+            if ((bytes = read(fd, buffer, (size_t)bytes)) <= 0)
+	    {
+	      pdfioStreamClose(st);
+	      _pdfioFileError(dict->pdf, "Early end-of-file in image file.");
+	      return (NULL);
+	    }
+
+            crc    = update_png_crc(crc, buffer, (size_t)bytes);
+            length -= bytes;
+          }
           break;
     }
+
+    // Verify the CRC...
+    crc ^= 0xffffffff;
+
+    if (read(fd, buffer, 4) != 4)
+    {
+      pdfioStreamClose(st);
+      _pdfioFileError(dict->pdf, "Unable to read CRC.");
+      return (NULL);
+    }
+
+    temp = (unsigned)((buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3]);
+    if (temp != crc)
+    {
+      pdfioStreamClose(st);
+      _pdfioFileError(dict->pdf, "Bad CRC.");
+      return (NULL);
+    }
   }
 
   return (NULL);
 }
 
 
+//
+// 'update_png_crc()' - Update the CRC-32 value for a PNG chunk.
+//
+
+static unsigned				// O - CRC-32 value
+update_png_crc(
+    unsigned            crc,		// I - CRC-32 value
+    const unsigned char *buffer,	// I - Buffer
+    size_t              length)		// I - Length of buffer
+{
+  while (length > 0)
+  {
+    crc = png_crc_table[(crc ^ *buffer) & 0xff] ^ (crc >> 8);
+    buffer ++;
+    length --;
+  }
+
+  return (crc);
+}
+
+
 //
 // 'write_string()' - Write a PDF string.
 //

pdfio-content.h

@@ -87,7 +87,7 @@ extern const double	pdfioSRGBWhitePoint[3] PDFIO_PUBLIC;
 extern pdfio_array_t	*pdfioArrayCreateCalibratedColorFromMatrix(pdfio_file_t *pdf, size_t num_colors, double gamma, const double matrix[3][3], const double white_point[3]) PDFIO_PUBLIC;
 extern pdfio_array_t	*pdfioArrayCreateCalibratedColorFromPrimaries(pdfio_file_t *pdf, size_t num_colors, double gamma, double wx, double wy, double rx, double ry, double gx, double gy, double bx, double by) PDFIO_PUBLIC;
 extern pdfio_array_t	*pdfioArrayCreateICCBasedColor(pdfio_file_t *pdf, pdfio_obj_t *icc_object) PDFIO_PUBLIC;
-extern pdfio_array_t	*pdfioArrayCreateIndexedColor(pdfio_file_t *pdf, size_t num_colors, const unsigned char colors[][3]) PDFIO_PUBLIC;
+extern pdfio_array_t	*pdfioArrayCreateIndexedColor(pdfio_file_t *pdf, size_t num_colors, const unsigned char *colors) PDFIO_PUBLIC;
 
 // PDF content drawing functions...
 extern bool		pdfioContentClip(pdfio_stream_t *st, bool even_odd) PDFIO_PUBLIC;