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1 /*M///////////////////////////////////////////////////////////////////////////////////////
2 //
3 //  IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
4 //
5 //  By downloading, copying, installing or using the software you agree to this license.
6 //  If you do not agree to this license, do not download, install,
7 //  copy or use the software.
8 //
9 //
10 //                        Intel License Agreement
11 //                For Open Source Computer Vision Library
12 //
13 // Copyright (C) 2000, Intel Corporation, all rights reserved.
14 // Third party copyrights are property of their respective owners.
15 //
16 // Redistribution and use in source and binary forms, with or without modification,
17 // are permitted provided that the following conditions are met:
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19 //   * Redistribution's of source code must retain the above copyright notice,
20 //     this list of conditions and the following disclaimer.
21 //
22 //   * Redistribution's in binary form must reproduce the above copyright notice,
23 //     this list of conditions and the following disclaimer in the documentation
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40 //M*/
41 
42 #include "_highgui.h"
43 
44 #ifdef HAVE_PNG
45 
46 /****************************************************************************************\
47     This part of the file implements PNG codec on base of libpng library,
48     in particular, this code is based on example.c from libpng
49     (see otherlibs/_graphics/readme.txt for copyright notice)
50     and png2bmp sample from libpng distribution (Copyright (C) 1999-2001 MIYASAKA Masaru)
51 \****************************************************************************************/
52 
53 #if defined WIN32 || defined HAVE_PNG_H
54 #include <png.h>
55 #else
56 #include <libpng/png.h>
57 #endif
58 #include "grfmt_png.h"
59 
60 // PNG Filter Factory
GrFmtPng()61 GrFmtPng::GrFmtPng()
62 {
63     m_sign_len = 8;
64     m_signature = "\x89\x50\x4e\x47\xd\xa\x1a\xa";
65     m_description = "Portable Network Graphics files (*.png)";
66 }
67 
68 
~GrFmtPng()69 GrFmtPng::~GrFmtPng()
70 {
71 }
72 
73 
NewReader(const char * filename)74 GrFmtReader* GrFmtPng::NewReader( const char* filename )
75 {
76     return new GrFmtPngReader( filename );
77 }
78 
79 
NewWriter(const char * filename)80 GrFmtWriter* GrFmtPng::NewWriter( const char* filename )
81 {
82     return new GrFmtPngWriter( filename );
83 }
84 
85 
CheckSignature(const char * signature)86 bool  GrFmtPng::CheckSignature( const char* signature )
87 {
88     return png_check_sig( (uchar*)signature, m_sign_len ) != 0;
89 }
90 
91 /////////////////////// GrFmtPngReader ///////////////////
92 
GrFmtPngReader(const char * filename)93 GrFmtPngReader::GrFmtPngReader( const char* filename ) : GrFmtReader( filename )
94 {
95     m_color_type = m_bit_depth = 0;
96     m_png_ptr = 0;
97     m_info_ptr = m_end_info = 0;
98     m_f = 0;
99 }
100 
101 
~GrFmtPngReader()102 GrFmtPngReader::~GrFmtPngReader()
103 {
104 }
105 
106 
Close()107 void  GrFmtPngReader::Close()
108 {
109     if( m_f )
110     {
111         fclose( m_f );
112         m_f = 0;
113     }
114 
115     if( m_png_ptr )
116     {
117         png_structp png_ptr = (png_structp)m_png_ptr;
118         png_infop info_ptr = (png_infop)m_info_ptr;
119         png_infop end_info = (png_infop)m_end_info;
120         png_destroy_read_struct( &png_ptr, &info_ptr, &end_info );
121         m_png_ptr = m_info_ptr = m_end_info = 0;
122     }
123     GrFmtReader::Close();
124 }
125 
126 
ReadHeader()127 bool  GrFmtPngReader::ReadHeader()
128 {
129     bool result = false;
130 
131     Close();
132 
133     png_structp png_ptr = png_create_read_struct( PNG_LIBPNG_VER_STRING, 0, 0, 0 );
134 
135     if( png_ptr )
136     {
137         png_infop info_ptr = png_create_info_struct( png_ptr );
138         png_infop end_info = png_create_info_struct( png_ptr );
139 
140         m_png_ptr = png_ptr;
141         m_info_ptr = info_ptr;
142         m_end_info = end_info;
143 
144         if( info_ptr && end_info )
145         {
146             if( setjmp( png_ptr->jmpbuf ) == 0 )
147             {
148                 m_f = fopen( m_filename, "rb" );
149                 if( m_f )
150                 {
151                     png_uint_32 width, height;
152                     int bit_depth, color_type;
153 
154                     png_init_io( png_ptr, m_f );
155                     png_read_info( png_ptr, info_ptr );
156 
157                     png_get_IHDR( png_ptr, info_ptr, &width, &height,
158                                   &bit_depth, &color_type, 0, 0, 0 );
159 
160                     m_iscolor = color_type == PNG_COLOR_TYPE_RGB ||
161                                 color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
162                                 color_type == PNG_COLOR_TYPE_PALETTE;
163 
164                     m_width = (int)width;
165                     m_height = (int)height;
166                     m_color_type = color_type;
167                     m_bit_depth = bit_depth;
168 
169                     result = true;
170                 }
171             }
172         }
173     }
174 
175     if( !result )
176         Close();
177 
178     return result;
179 }
180 
181 
ReadData(uchar * data,int step,int color)182 bool  GrFmtPngReader::ReadData( uchar* data, int step, int color )
183 {
184     bool result = false;
185     uchar** buffer = 0;
186 
187     color = color > 0 || ( m_iscolor && color < 0 );
188 
189     if( m_png_ptr && m_info_ptr && m_end_info && m_width && m_height )
190     {
191         png_structp png_ptr = (png_structp)m_png_ptr;
192         png_infop info_ptr = (png_infop)m_info_ptr;
193         png_infop end_info = (png_infop)m_end_info;
194 
195         if( setjmp(png_ptr->jmpbuf) == 0 )
196         {
197             int y;
198 
199             if( m_bit_depth > 8 && !m_native_depth )
200                 png_set_strip_16( png_ptr );
201             else if( !isBigEndian() )
202                 png_set_swap( png_ptr );
203 
204             /* observation: png_read_image() writes 400 bytes beyond
205              * end of data when reading a 400x118 color png
206              * "mpplus_sand.png".  OpenCV crashes even with demo
207              * programs.  Looking at the loaded image I'd say we get 4
208              * bytes per pixel instead of 3 bytes per pixel.  Test
209              * indicate that it is a good idea to always ask for
210              * stripping alpha..  18.11.2004 Axel Walthelm
211              */
212             png_set_strip_alpha( png_ptr );
213 
214             if( m_color_type == PNG_COLOR_TYPE_PALETTE )
215                 png_set_palette_to_rgb( png_ptr );
216 
217             if( m_color_type == PNG_COLOR_TYPE_GRAY && m_bit_depth < 8 )
218                 png_set_gray_1_2_4_to_8( png_ptr );
219 
220             if( m_iscolor && color )
221                 png_set_bgr( png_ptr ); // convert RGB to BGR
222             else if( color )
223                 png_set_gray_to_rgb( png_ptr ); // Gray->RGB
224             else
225                 png_set_rgb_to_gray( png_ptr, 1, -1, -1 ); // RGB->Gray
226 
227             png_read_update_info( png_ptr, info_ptr );
228 
229             buffer = new uchar*[m_height];
230 
231             for( y = 0; y < m_height; y++ )
232                 buffer[y] = data + y*step;
233 
234             png_read_image( png_ptr, buffer );
235             png_read_end( png_ptr, end_info );
236 
237             result = true;
238         }
239     }
240 
241     Close();
242     delete[] buffer;
243 
244     return result;
245 }
246 
247 
248 /////////////////////// GrFmtPngWriter ///////////////////
249 
250 
GrFmtPngWriter(const char * filename)251 GrFmtPngWriter::GrFmtPngWriter( const char* filename ) : GrFmtWriter( filename )
252 {
253 }
254 
255 
~GrFmtPngWriter()256 GrFmtPngWriter::~GrFmtPngWriter()
257 {
258 }
259 
260 
IsFormatSupported(int depth)261 bool  GrFmtPngWriter::IsFormatSupported( int depth )
262 {
263     return depth == IPL_DEPTH_8U || depth == IPL_DEPTH_16U;
264 }
265 
WriteImage(const uchar * data,int step,int width,int height,int depth,int channels)266 bool  GrFmtPngWriter::WriteImage( const uchar* data, int step,
267                                   int width, int height, int depth, int channels )
268 {
269     png_structp png_ptr = png_create_write_struct( PNG_LIBPNG_VER_STRING, 0, 0, 0 );
270     png_infop info_ptr = 0;
271     FILE* f = 0;
272     uchar** buffer = 0;
273     int y;
274     bool result = false;
275 
276     if( depth != IPL_DEPTH_8U && depth != IPL_DEPTH_16U )
277         return false;
278 
279     if( png_ptr )
280     {
281         info_ptr = png_create_info_struct( png_ptr );
282 
283         if( info_ptr )
284         {
285             if( setjmp( png_ptr->jmpbuf ) == 0 )
286             {
287                 f = fopen( m_filename, "wb" );
288 
289                 if( f )
290                 {
291                     png_init_io( png_ptr, f );
292 
293                     png_set_compression_mem_level( png_ptr, MAX_MEM_LEVEL );
294 
295                     png_set_IHDR( png_ptr, info_ptr, width, height, depth,
296                         channels == 1 ? PNG_COLOR_TYPE_GRAY :
297                         channels == 3 ? PNG_COLOR_TYPE_RGB : PNG_COLOR_TYPE_RGBA,
298                         PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
299                         PNG_FILTER_TYPE_DEFAULT );
300 
301                     png_write_info( png_ptr, info_ptr );
302 
303                     png_set_bgr( png_ptr );
304                     if( !isBigEndian() )
305                         png_set_swap( png_ptr );
306 
307                     buffer = new uchar*[height];
308                     for( y = 0; y < height; y++ )
309                         buffer[y] = (uchar*)(data + y*step);
310 
311                     png_write_image( png_ptr, buffer );
312                     png_write_end( png_ptr, info_ptr );
313 
314                     delete[] buffer;
315 
316                     result = true;
317                 }
318             }
319         }
320     }
321 
322     png_destroy_write_struct( &png_ptr, &info_ptr );
323 
324     if(f) fclose( f );
325 
326     return result;
327 }
328 
329 #endif
330 
331 /* End of file. */
332 
333 
334