From a519a5dec6e1fd5974a7647cc93f153390c5d3e2 Mon Sep 17 00:00:00 2001
From: Přemysl Eric Janouch <p@janouch.name>
Date: Sun, 5 Dec 2021 17:50:36 +0100
Subject: jpeginfo: describe Photoshop records
---
tools/jpeginfo.c | 233 ++++++++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 221 insertions(+), 12 deletions(-)
(limited to 'tools')
diff --git a/tools/jpeginfo.c b/tools/jpeginfo.c
index 4bbf589..eeef88b 100644
--- a/tools/jpeginfo.c
+++ b/tools/jpeginfo.c
@@ -25,6 +25,18 @@
// --- Utilities ---------------------------------------------------------------
+static char *
+binhex(const uint8_t *data, size_t len)
+{
+ static const char *alphabet = "0123456789abcdef";
+ char *buf = calloc(1, len * 2 + 1), *p = buf;
+ for (size_t i = 0; i < len; i++) {
+ *p++ = alphabet[data[i] >> 4];
+ *p++ = alphabet[data[i] & 0xF];
+ }
+ return buf;
+}
+
static uint32_t
u32be(const uint8_t *p)
{
@@ -78,7 +90,8 @@ u16le(const uint8_t *p)
// https://www.cipa.jp/e/std/std-sec.html
//
// libtiff is a mess, and the format is not particularly complicated.
-// Exif libraries are senselessly copylefted.
+// Exiv2 is senselessly copylefted, and cannot do much.
+// ExifTool is too user-oriented.
static struct un {
uint32_t (*u32) (const uint8_t *);
@@ -542,8 +555,12 @@ static struct tiff_entry tiff_entries[] = {
{"ReferenceBlackWhite", 532, NULL},
{"ImageID", 32781, NULL}, // Adobe PageMaker 6.0 TIFF Technical Notes
{"Copyright", 33432, NULL},
+ // TODO(p): Extract PSIRs, like we do directly with the JPEG segment.
+ {"Photoshop", 34377, NULL}, // Adobe XMP Specification Part 3 Table 12/39
{"Exif IFD Pointer", 34665, NULL}, // Exif 2.3
{"GPS Info IFD Pointer", 34853, NULL}, // Exif 2.3
+ // TODO(p): Extract IPTC DataSets, like we do directly with PSIRs.
+ {"IPTC", 37723, NULL}, // Adobe XMP Specification Part 3 Table 12/39
{"ImageSourceData", 37724, NULL}, // Adobe Photoshop TIFF Technical Notes
{}
};
@@ -906,12 +923,7 @@ static jv
parse_exif_undefined(struct tiffer_entry *entry)
{
// Sometimes, it can be ASCII, but the safe bet is to hex-encode it.
- const char *alphabet = "0123456789abcdef";
- char *buf = calloc(1, 2 * entry->remaining_count + 1);
- for (uint32_t i = 0; i < entry->remaining_count; i++) {
- buf[2 * i + 0] = alphabet[entry->p[i] >> 4];
- buf[2 * i + 1] = alphabet[entry->p[i] & 0xF];
- }
+ char *buf = binhex(entry->p, entry->remaining_count);
jv s = jv_string(buf);
free(buf);
return s;
@@ -1090,16 +1102,213 @@ parse_icc(jv o, const uint8_t *profile, size_t profile_len)
// --- Photoshop Image Resources -----------------------------------------------
// Adobe XMP Specification Part 3: Storage in Files, 2020/1, 1.1.3 + 3.1.3
// https://www.adobe.com/devnet-apps/photoshop/fileformatashtml/
+// Unless otherwise noted, the descriptions are derived from the above document.
+
+static struct {
+ uint16_t id;
+ const char *description;
+} psir_descriptions[] = {
+ {1000, "Number of channels, rows, columns, depth, mode"},
+ {1001, "Macintosh print manager print info record"},
+ {1002, "Macintosh page format information"},
+ {1003, "Indexed color table"},
+ {1005, "Resolution information"},
+ {1006, "Names of alpha channels (Pascal strings)"},
+ {1007, "Display information"},
+ {1008, "Caption (Pascal string)"}, // XMP Part 3 3.3.3
+ {1009, "Border information"},
+ {1010, "Background color"},
+ {1011, "Print flags"},
+ {1012, "Grayscale and multichannel halftoning information"},
+ {1013, "Color halftoning information"},
+ {1014, "Duotone halftoning information"},
+ {1015, "Grayscale and multichannel transfer function"},
+ {1016, "Color transfer functions"},
+ {1017, "Duotone transfer functions"},
+ {1018, "Duotone image information"},
+ {1019, "Effective B/W values for the dot range"},
+ {1020, "Caption"}, // XMP Part 3 3.3.3
+ {1021, "EPS options"},
+ {1022, "Quick Mask information"},
+ {1023, "(Obsolete)"},
+ {1024, "Layer state information"},
+ {1025, "Working path (not saved)"},
+ {1026, "Layers group information"},
+ {1027, "(Obsolete)"},
+ {1028, "IPTC DataSets"}, // XMP Part 3 3.3.3
+ {1029, "Image mode for raw format files"},
+ {1030, "JPEG quality"},
+ {1032, "Grid and guides information"},
+ {1033, "Thumbnail resource"},
+ {1034, "Copyright flag"},
+ {1035, "Copyright information URL"}, // XMP Part 3 3.3.3
+ {1036, "Thumbnail resource"},
+ {1037, "Global lighting angle for effects layer"},
+ {1038, "Color samplers information"},
+ {1039, "ICC profile"},
+ {1040, "Watermark"},
+ {1041, "ICC untagged profile flag"},
+ {1042, "Effects visible flag"},
+ {1043, "Spot halftone"},
+ {1044, "Document-specific IDs seed number"},
+ {1045, "Unicode alpha names"},
+ {1046, "Indexed color table count"},
+ {1047, "Transparent color index"},
+ {1049, "Global altitude"},
+ {1050, "Slices"},
+ {1051, "Workflow URL"},
+ {1052, "Jump To XPEP"},
+ {1053, "Alpha identifiers"},
+ {1054, "URL list"},
+ {1057, "Version info"},
+ {1058, "Exif metadata 1"},
+ {1059, "Exif metadata 3"},
+ {1060, "XMP metadata"},
+ {1061, "MD5 digest of IPTC data"}, // XMP Part 3 3.3.3
+ {1062, "Print scale"},
+ {1064, "Pixel aspect ratio"},
+ {1065, "Layer comps"},
+ {1066, "Alternate duotone colors"},
+ {1067, "Alternate spot colors"},
+ {1069, "Layer selection IDs"},
+ {1070, "HDR toning information"},
+ {1071, "Print info"},
+ {1072, "Layer group(s) enabled ID"},
+ {1073, "Color samplers"},
+ {1074, "Measurement scale"},
+ {1075, "Timeline information"},
+ {1076, "Sheet disclosure"},
+ {1077, "Display information to support floating point colors"},
+ {1078, "Onion skins"},
+ {1080, "Count information"},
+ {1082, "Print information"},
+ {1083, "Print style"},
+ {1084, "Macintosh NSPrintInfo"},
+ {1085, "Windows DEVMODE"},
+ {1086, "Autosave file path"},
+ {1087, "Autosave format"},
+ {1088, "Path selection state"},
+ // {2000-2997, "Saved paths"},
+ {2999, "Name of clipping path"},
+ {3000, "Origin path information"},
+ // {4000-4999, "Plug-in resource"},
+ {7000, "Image Ready variables"},
+ {7001, "Image Ready data sets"},
+ {7002, "Image Ready default selected state"},
+ {7003, "Image Ready 7 rollover expanded state"},
+ {7004, "Image Ready rollover expanded state"},
+ {7005, "Image Ready save layer settings"},
+ {7006, "Image Ready version"},
+ {8000, "Lightroom workflow"},
+ {10000, "Print flags"},
+ {}
+};
+
+static jv
+process_psir_thumbnail(jv res, const uint8_t *data, size_t len)
+{
+ uint32_t format_number = u32be(data + 0);
+ uint32_t compressed_size = u32be(data + 20);
+
+ // TODO(p): Recurse into the thumbnail if it's a JPEG.
+ jv format = jv_number(format_number);
+ switch (format_number) {
+ break; case 0: format = jv_string("kJpegRGB");
+ break; case 1: format = jv_string("kRawRGB");
+ }
+
+ res = jv_object_merge(res, JV_OBJECT(
+ jv_string("Format"), format,
+ jv_string("Width"), jv_number(u32be(data + 4)),
+ jv_string("Height"), jv_number(u32be(data + 8)),
+ jv_string("Stride"), jv_number(u32be(data + 12)),
+ jv_string("TotalSize"), jv_number(u32be(data + 16)),
+ jv_string("CompressedSize"), jv_number(compressed_size),
+ jv_string("BitsPerPixel"), jv_number(u16be(data + 24)),
+ jv_string("Planes"), jv_number(u16be(data + 26))
+ ));
+ if (28 + compressed_size <= len) {
+ char *buf = binhex(data + 28, compressed_size);
+ res = jv_set(res, jv_string("Data"), jv_string(buf));
+ free(buf);
+ }
+ return res;
+}
+
+static const char *
+process_iptc_dataset(jv *a, const uint8_t **p, size_t len)
+{
+ const uint8_t *header = *p;
+ if (len < 5)
+ return "unexpected end of IPTC data";
+ if (*header != 0x1c)
+ return "invalid tag marker";
+
+ uint8_t record = header[1];
+ uint8_t dataset = header[2];
+ uint16_t byte_count = header[3] << 8 | header[4];
+
+ // TODO(p): Although highly unlikely to appear, we could decode it.
+ if (byte_count & 0x8000)
+ return "unsupported extended DataSet";
+ if (len - 5 < byte_count)
+ return "data overrun";
+
+ char *buf = binhex(header + 5, byte_count);
+ *p += 5 + byte_count;
+ *a = jv_array_append(*a, JV_OBJECT(
+ jv_string("DataSet"), jv_string_fmt("%u:%u", record, dataset),
+ jv_string("Data"), jv_string(buf)
+ ));
+ free(buf);
+ return NULL;
+}
+
+static jv
+process_psir_iptc(jv res, const uint8_t *data, size_t len)
+{
+ // https://iptc.org/standards/iim/
+ // https://iptc.org/std/IIM/4.2/specification/IIMV4.2.pdf
+ jv a = jv_array();
+ const uint8_t *end = data + len;
+ while (data < end) {
+ const char *err = process_iptc_dataset(&a, &data, end - data);
+ if (err) {
+ a = jv_array_append(a, jv_string(err));
+ break;
+ }
+ }
+ return jv_set(res, jv_string("DataSets"), a);
+}
static jv
process_psir(jv o, uint16_t resource_id, const char *name,
const uint8_t *data, size_t len)
{
- // TODO(p): These is more to extract here. The name is most often empty.
- (void) name;
- (void) data;
- (void) len;
- return add_to_subarray(o, "PSIR", jv_number(resource_id));
+ const char *description = NULL;
+ if (resource_id >= 2000 && resource_id <= 2997)
+ description = "Saved paths";
+ if (resource_id >= 4000 && resource_id <= 4999)
+ description = "Plug-in resource";
+ for (size_t i = 0; psir_descriptions[i].id; i++)
+ if (psir_descriptions[i].id == resource_id)
+ description = psir_descriptions[i].description;
+
+ jv res = JV_OBJECT(
+ jv_string("name"), jv_string(name),
+ jv_string("id"), jv_number(resource_id),
+ jv_string("description"),
+ description ? jv_string(description) : jv_null(),
+ jv_string("size"), jv_number(len)
+ );
+
+ // Both are thumbnails, older is BGR, newer is RGB.
+ if ((resource_id == 1033 || resource_id == 1036) && len >= 28)
+ res = process_psir_thumbnail(res, data, len);
+ if (resource_id == 1028)
+ res = process_psir_iptc(res, data, len);
+
+ return add_to_subarray(o, "PSIR", res);
}
static jv
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