imsanity / libs / imagecreatefrombmp.php

imagecreatefrombmp.php in Imsanity 2.5.0, at libs/imagecreatefrombmp.php

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1	<?php
2	/**
3	* The imagecreatefrombmp function converts a bmp to an image resource
4	*
5	* @author http://www.programmierer-forum.de/function-imagecreatefrombmp-laeuft-mit-allen-bitraten-t143137.htm
6	* @package Imsanity
7	*/
8
9	if ( ! function_exists( 'imagecreatefrombmp' ) ) {
10
11	/**
12	* Converts a bitmap (BMP) image into an image resource.
13	*
14	* @param string $filename The name of the image file.
15	* @return bool\|object False, or a GD image resource.
16	*/
17	function imagecreatefrombmp( $filename ) {
18	// version 1.1.
19	if ( ! is_readable( $filename ) ) {
20	/* translators: %s: the image filename */
21	trigger_error( sprintf( __( 'imagecreatefrombmp: Can not open %s!', 'imsanity' ), $filename ), E_USER_WARNING );
22	return false;
23	}
24	$fh = fopen( $filename, 'rb' );
25	if ( ! $fh ) {
26	/* translators: %s: the image filename */
27	trigger_error( sprintf( __( 'imagecreatefrombmp: Can not open %s!', 'imsanity' ), $filename ), E_USER_WARNING );
28	return false;
29	}
30	// read file header.
31	$meta = unpack( 'vtype/Vfilesize/Vreserved/Voffset', fread( $fh, 14 ) );
32	// check for bitmap.
33	if ( 19778 !== (int) $meta['type'] ) {
34	/* translators: %s: the image filename */
35	trigger_error( sprintf( __( 'imagecreatefrombmp: %s is not a bitmap!', 'imsanity' ), $filename ), E_USER_WARNING );
36	return false;
37	}
38	// read image header.
39	$meta += unpack( 'Vheadersize/Vwidth/Vheight/vplanes/vbits/Vcompression/Vimagesize/Vxres/Vyres/Vcolors/Vimportant', fread( $fh, 40 ) );
40	$bytes_read = 40;
41
42	// read additional bitfield header.
43	if ( 3 === (int) $meta['compression'] ) {
44	$meta += unpack( 'VrMask/VgMask/VbMask', fread( $fh, 12 ) );
45	$bytes_read += 12;
46	}
47
48	// set bytes and padding.
49	$meta['bytes'] = $meta['bits'] / 8;
50	$meta['decal'] = 4 - ( 4 * ( ( $meta['width'] * $meta['bytes'] / 4 ) - floor( $meta['width'] * $meta['bytes'] / 4 ) ) );
51	if ( 4 === (int) $meta['decal'] ) {
52	$meta['decal'] = 0;
53	}
54
55	// obtain imagesize.
56	if ( $meta['imagesize'] < 1 ) {
57	$meta['imagesize'] = $meta['filesize'] - $meta['offset'];
58	// in rare cases filesize is equal to offset so we need to read physical size.
59	if ( $meta['imagesize'] < 1 ) {
60	$meta['imagesize'] = filesize( $filename ) - $meta['offset'];
61	if ( $meta['imagesize'] < 1 ) {
62	/* translators: %s: the image filename */
63	trigger_error( sprintf( __( 'imagecreatefrombmp: Cannot obtain filesize of %s !', 'imsanity' ), $filename ), E_USER_WARNING );
64	return false;
65	}
66	}
67	}
68
69	// calculate colors.
70	$meta['colors'] = ! $meta['colors'] ? pow( 2, $meta['bits'] ) : $meta['colors'];
71
72	// read color palette.
73	$palette = array();
74	if ( $meta['bits'] < 16 ) {
75	$palette = unpack( 'l' . $meta['colors'], fread( $fh, $meta['colors'] * 4 ) );
76	// in rare cases the color value is signed.
77	if ( $palette[1] < 0 ) {
78	foreach ( $palette as $i => $color ) {
79	$palette[ $i ] = $color + 16777216;
80	}
81	}
82	}
83
84	// ignore extra bitmap headers.
85	if ( $meta['headersize'] > $bytes_read ) {
86	fread( $fh, $meta['headersize'] - $bytes_read );
87	}
88
89	// create gd image.
90	$im = imagecreatetruecolor( $meta['width'], $meta['height'] );
91	$data = fread( $fh, $meta['imagesize'] );
92
93	// uncompress data.
94	switch ( $meta['compression'] ) {
95	case 1:
96	$data = rle8_decode( $data, $meta['width'] );
97	break;
98	case 2:
99	$data = rle4_decode( $data, $meta['width'] );
100	break;
101	}
102
103	$p = 0;
104	$vide = chr( 0 );
105	$y = $meta['height'] - 1;
106	/* translators: %s: the image filename */
107	$error = sprintf( __( 'imagecreatefrombmp: %s has not enough data!', 'imsanity' ), $filename );
108	// loop through the image data beginning with the lower left corner.
109	while ( $y >= 0 ) {
110	$x = 0;
111	while ( $x < $meta['width'] ) {
112	switch ( $meta['bits'] ) {
113	case 32:
114	case 24:
115	$part = substr( $data, $p, 3 );
116	if ( ! $part ) {
117	trigger_error( $error, E_USER_WARNING );
118	return $im;
119	}
120	$color = unpack( 'V', $part . $vide );
121	break;
122	case 16:
123	$part = substr( $data, $p, 2 );
124	if ( ! $part ) {
125	trigger_error( $error, E_USER_WARNING );
126	return $im;
127	}
128	$color = unpack( 'v', $part );
129	if ( empty( $meta['rMask'] ) \|\| 0xf800 !== (int) $meta['rMask'] ) {
130	$color[1] = ( ( $color[1] & 0x7c00 ) >> 7 ) * 65536 + ( ( $color[1] & 0x03e0 ) >> 2 ) * 256 + ( ( $color[1] & 0x001f ) << 3 ); // 555.
131	} else {
132	$color[1] = ( ( $color[1] & 0xf800 ) >> 8 ) * 65536 + ( ( $color[1] & 0x07e0 ) >> 3 ) * 256 + ( ( $color[1] & 0x001f ) << 3 ); // 565.
133	}
134	break;
135	case 8:
136	$color = unpack( 'n', $vide . substr( $data, $p, 1 ) );
137	$color[1] = $palette[ $color[1] + 1 ];
138	break;
139	case 4:
140	$color = unpack( 'n', $vide . substr( $data, floor( $p ), 1 ) );
141	$color[1] = 0 === ( $p * 2 ) % 2 ? $color[1] >> 4 : $color[1] & 0x0F;
142	$color[1] = $palette[ $color[1] + 1 ];
143	break;
144	case 1:
145	$color = unpack( 'n', $vide . substr( $data, floor( $p ), 1 ) );
146	switch ( ( $p * 8 ) % 8 ) {
147	case 0:
148	$color[1] = $color[1] >> 7;
149	break;
150	case 1:
151	$color[1] = ( $color[1] & 0x40 ) >> 6;
152	break;
153	case 2:
154	$color[1] = ( $color[1] & 0x20 ) >> 5;
155	break;
156	case 3:
157	$color[1] = ( $color[1] & 0x10 ) >> 4;
158	break;
159	case 4:
160	$color[1] = ( $color[1] & 0x8 ) >> 3;
161	break;
162	case 5:
163	$color[1] = ( $color[1] & 0x4 ) >> 2;
164	break;
165	case 6:
166	$color[1] = ( $color[1] & 0x2 ) >> 1;
167	break;
168	case 7:
169	$color[1] = ( $color[1] & 0x1 );
170	break;
171	}
172	$color[1] = $palette[ $color[1] + 1 ];
173	break;
174	default:
175	/* translators: 1: the image filename 2: bitrate of image */
176	trigger_error( sprintf( __( 'imagecreatefrombmp: %1$s has %2$d bits and this is not supported!', 'imsanity' ), $filename, $meta['bits'] ), E_USER_WARNING );
177	return false;
178	}
179	imagesetpixel( $im, $x, $y, $color[1] );
180	$x++;
181	$p += $meta['bytes'];
182	}
183	$y--;
184	$p += $meta['decal'];
185	}
186	fclose( $fh );
187	return $im;
188	}
189	/**
190	* The original source for these functions no longer exists, but it appears to come from
191	* MSDN and has proliferated across many projects with only the stale link which now
192	* points to https://docs.microsoft.com/en-us/windows/desktop/gdi/bitmap-compression.
193	*/
194	/**
195	* Decoder for RLE8 compression in windows bitmaps.
196	*
197	* @param string $str Data to decode.
198	* @param integer $width Image width.
199	*
200	* @return string
201	*/
202	function rle8_decode( $str, $width ) {
203	$linewidth = $width + ( 3 - ( $width - 1 ) % 4 );
204	$out = '';
205	$cnt = strlen( $str );
206
207	for ( $i = 0; $i < $cnt; $i++ ) {
208	$o = ord( $str[ $i ] );
209	switch ( $o ) {
210	case 0: // ESCAPE.
211	$i++;
212	switch ( ord( $str[ $i ] ) ) {
213	case 0: // NEW LINE.
214	$padcnt = $linewidth - strlen( $out ) % $linewidth;
215	if ( $padcnt < $linewidth ) {
216	$out .= str_repeat( chr( 0 ), $padcnt ); // pad line.
217	}
218	break;
219	case 1: // END OF FILE.
220	$padcnt = $linewidth - strlen( $out ) % $linewidth;
221	if ( $padcnt < $linewidth ) {
222	$out .= str_repeat( chr( 0 ), $padcnt ); // pad line.
223	}
224	break 3;
225	case 2: // DELTA.
226	$i += 2;
227	break;
228	default: // ABSOLUTE MODE.
229	$num = ord( $str[ $i ] );
230	for ( $j = 0; $j < $num; $j++ ) {
231	$out .= $str[ ++$i ];
232	}
233	if ( $num % 2 ) {
234	$i++;
235	}
236	}
237	break;
238	default:
239	$out .= str_repeat( $str[ ++$i ], $o );
240	}
241	}
242	return $out;
243	}
244
245	/**
246	* Decoder for RLE4 compression in windows bitmaps.
247	*
248	* @param string $str Data to decode.
249	* @param integer $width Image width.
250	* @return string
251	*/
252	function rle4_decode( $str, $width ) {
253	$w = floor( $width / 2 ) + ( $width % 2 );
254	$linewidth = $w + ( 3 - ( ( $width - 1 ) / 2 ) % 4 );
255	$pixels = array();
256	$cnt = strlen( $str );
257	$c = 0;
258
259	for ( $i = 0; $i < $cnt; $i++ ) {
260	$o = ord( $str[ $i ] );
261	switch ( $o ) {
262	case 0: // ESCAPE.
263	$i++;
264	switch ( ord( $str[ $i ] ) ) {
265	case 0: // NEW LINE.
266	while ( 0 !== count( $pixels ) % $linewidth ) {
267	$pixels[] = 0;
268	}
269	break;
270	case 1: // END OF FILE.
271	while ( 0 !== count( $pixels ) % $linewidth ) {
272	$pixels[] = 0;
273	}
274	break 3;
275	case 2: // DELTA.
276	$i += 2;
277	break;
278	default: // ABSOLUTE MODE.
279	$num = ord( $str[ $i ] );
280	for ( $j = 0; $j < $num; $j++ ) {
281	if ( 0 === $j % 2 ) {
282	$c = ord( $str[ ++$i ] );
283	$pixels[] = ( $c & 240 ) >> 4;
284	} else {
285	$pixels[] = $c & 15;
286	}
287	}
288
289	if ( 0 === $num % 2 ) {
290	$i++;
291	}
292	}
293	break;
294	default:
295	$c = ord( $str[ ++$i ] );
296	for ( $j = 0; $j < $o; $j++ ) {
297	$pixels[] = ( 0 === $j % 2 ? ( $c & 240 ) >> 4 : $c & 15 );
298	}
299	}
300	}
301
302	$out = '';
303	if ( count( $pixels ) % 2 ) {
304	$pixels[] = 0;
305	}
306
307	$cnt = count( $pixels ) / 2;
308
309	for ( $i = 0; $i < $cnt; $i++ ) {
310	$out .= chr( 16 * $pixels[ 2 * $i ] + $pixels[ 2 * $i + 1 ] );
311	}
312
313	return $out;
314	}
315	}
316