jpeg revision 1.1.1.2
1 2 #------------------------------------------------------------------------------ 3 # $File: jpeg,v 1.16 2011/01/04 19:29:32 rrt Exp $ 4 # JPEG images 5 # SunOS 5.5.1 had 6 # 7 # 0 string \377\330\377\340 JPEG file 8 # 0 string \377\330\377\356 JPG file 9 # 10 # both of which turn into "JPEG image data" here. 11 # 12 0 beshort 0xffd8 JPEG image data 13 !:mime image/jpeg 14 !:apple 8BIMJPEG 15 !:strength +1 16 >6 string JFIF \b, JFIF standard 17 # The following added by Erik Rossen <rossen (a] freesurf.ch> 1999-09-06 18 # in a vain attempt to add image size reporting for JFIF. Note that these 19 # tests are not fool-proof since some perfectly valid JPEGs are currently 20 # impossible to specify in magic(4) format. 21 # First, a little JFIF version info: 22 >>11 byte x \b %d. 23 >>12 byte x \b%02d 24 # Next, the resolution or aspect ratio of the image: 25 #>>13 byte 0 \b, aspect ratio 26 #>>13 byte 1 \b, resolution (DPI) 27 #>>13 byte 2 \b, resolution (DPCM) 28 #>>4 beshort x \b, segment length %d 29 # Next, show thumbnail info, if it exists: 30 >>18 byte !0 \b, thumbnail %dx 31 >>>19 byte x \b%d 32 33 # EXIF moved down here to avoid reporting a bogus version number, 34 # and EXIF version number printing added. 35 # - Patrik R=E5dman <patrik+file-magic (a] iki.fi> 36 >6 string Exif \b, EXIF standard 37 # Look for EXIF IFD offset in IFD 0, and then look for EXIF version tag in EXIF IFD. 38 # All possible combinations of entries have to be enumerated, since no looping 39 # is possible. And both endians are possible... 40 # The combinations included below are from real-world JPEGs. 41 # Little-endian 42 >>12 string II 43 # IFD 0 Entry #5: 44 >>>70 leshort 0x8769 45 # EXIF IFD Entry #1: 46 >>>>(78.l+14) leshort 0x9000 47 >>>>>(78.l+23) byte x %c 48 >>>>>(78.l+24) byte x \b.%c 49 >>>>>(78.l+25) byte !0x30 \b%c 50 # IFD 0 Entry #9: 51 >>>118 leshort 0x8769 52 # EXIF IFD Entry #3: 53 >>>>(126.l+38) leshort 0x9000 54 >>>>>(126.l+47) byte x %c 55 >>>>>(126.l+48) byte x \b.%c 56 >>>>>(126.l+49) byte !0x30 \b%c 57 # IFD 0 Entry #10 58 >>>130 leshort 0x8769 59 # EXIF IFD Entry #3: 60 >>>>(138.l+38) leshort 0x9000 61 >>>>>(138.l+47) byte x %c 62 >>>>>(138.l+48) byte x \b.%c 63 >>>>>(138.l+49) byte !0x30 \b%c 64 # EXIF IFD Entry #4: 65 >>>>(138.l+50) leshort 0x9000 66 >>>>>(138.l+59) byte x %c 67 >>>>>(138.l+60) byte x \b.%c 68 >>>>>(138.l+61) byte !0x30 \b%c 69 # EXIF IFD Entry #5: 70 >>>>(138.l+62) leshort 0x9000 71 >>>>>(138.l+71) byte x %c 72 >>>>>(138.l+72) byte x \b.%c 73 >>>>>(138.l+73) byte !0x30 \b%c 74 # IFD 0 Entry #11 75 >>>142 leshort 0x8769 76 # EXIF IFD Entry #3: 77 >>>>(150.l+38) leshort 0x9000 78 >>>>>(150.l+47) byte x %c 79 >>>>>(150.l+48) byte x \b.%c 80 >>>>>(150.l+49) byte !0x30 \b%c 81 # EXIF IFD Entry #4: 82 >>>>(150.l+50) leshort 0x9000 83 >>>>>(150.l+59) byte x %c 84 >>>>>(150.l+60) byte x \b.%c 85 >>>>>(150.l+61) byte !0x30 \b%c 86 # EXIF IFD Entry #5: 87 >>>>(150.l+62) leshort 0x9000 88 >>>>>(150.l+71) byte x %c 89 >>>>>(150.l+72) byte x \b.%c 90 >>>>>(150.l+73) byte !0x30 \b%c 91 # Big-endian 92 >>12 string MM 93 # IFD 0 Entry #9: 94 >>>118 beshort 0x8769 95 # EXIF IFD Entry #1: 96 >>>>(126.L+14) beshort 0x9000 97 >>>>>(126.L+23) byte x %c 98 >>>>>(126.L+24) byte x \b.%c 99 >>>>>(126.L+25) byte !0x30 \b%c 100 # EXIF IFD Entry #3: 101 >>>>(126.L+38) beshort 0x9000 102 >>>>>(126.L+47) byte x %c 103 >>>>>(126.L+48) byte x \b.%c 104 >>>>>(126.L+49) byte !0x30 \b%c 105 # IFD 0 Entry #10 106 >>>130 beshort 0x8769 107 # EXIF IFD Entry #3: 108 >>>>(138.L+38) beshort 0x9000 109 >>>>>(138.L+47) byte x %c 110 >>>>>(138.L+48) byte x \b.%c 111 >>>>>(138.L+49) byte !0x30 \b%c 112 # EXIF IFD Entry #5: 113 >>>>(138.L+62) beshort 0x9000 114 >>>>>(138.L+71) byte x %c 115 >>>>>(138.L+72) byte x \b.%c 116 >>>>>(138.L+73) byte !0x30 \b%c 117 # IFD 0 Entry #11 118 >>>142 beshort 0x8769 119 # EXIF IFD Entry #4: 120 >>>>(150.L+50) beshort 0x9000 121 >>>>>(150.L+59) byte x %c 122 >>>>>(150.L+60) byte x \b.%c 123 >>>>>(150.L+61) byte !0x30 \b%c 124 # Here things get sticky. We can do ONE MORE marker segment with 125 # indirect addressing, and that's all. It would be great if we could 126 # do pointer arithemetic like in an assembler language. Christos? 127 # And if there was some sort of looping construct to do searches, plus a few 128 # named accumulators, it would be even more effective... 129 # At least we can show a comment if no other segments got inserted before: 130 >(4.S+5) byte 0xFE \b, comment: 131 >>(4.S+6) pstring/HJ x "%s" 132 # Or, we can show the encoding type (I've included only the three most common) 133 # and image dimensions if we are lucky and the SOFn (image segment) is here: 134 >(4.S+5) byte 0xC0 \b, baseline 135 >>(4.S+6) byte x \b, precision %d 136 >>(4.S+7) beshort x \b, %dx 137 >>(4.S+9) beshort x \b%d 138 >(4.S+5) byte 0xC1 \b, extended sequential 139 >>(4.S+6) byte x \b, precision %d 140 >>(4.S+7) beshort x \b, %dx 141 >>(4.S+9) beshort x \b%d 142 >(4.S+5) byte 0xC2 \b, progressive 143 >>(4.S+6) byte x \b, precision %d 144 >>(4.S+7) beshort x \b, %dx 145 >>(4.S+9) beshort x \b%d 146 # I've commented-out quantisation table reporting. I doubt anyone cares yet. 147 #>(4.S+5) byte 0xDB \b, quantisation table 148 #>>(4.S+6) beshort x \b length=%d 149 #>14 beshort x \b, %d x 150 #>16 beshort x \b %d 151 152 # HSI is Handmade Software's proprietary JPEG encoding scheme 153 0 string hsi1 JPEG image data, HSI proprietary 154 155 # From: David Santinoli <david (a] santinoli.com> 156 0 string \x00\x00\x00\x0C\x6A\x50\x20\x20\x0D\x0A\x87\x0A JPEG 2000 image data 157 158 # Type: JPEG 2000 codesream 159 # From: Mathieu Malaterre <mathieu.malaterre (a] gmail.com> 160 0 belong 0xff4fff51 JPEG 2000 codestream 161 45 beshort 0xff52 162
Indexes created Thu Sep 17 00:24:55 UTC 2026