2004-09-01 Lutz Mueller <lutz@users.sourceforge.net>

	* libexif/exif-tag.c: First ideas on how to support generation of
	  mandatory exif tags for a new image.

diff --git a/ChangeLog b/ChangeLog
index 13e1a7f..b170019 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2004-09-01  Lutz Mueller <lutz@users.sourceforge.net>
 
+       * libexif/exif-tag.c: First ideas on how to support generation of
+         mandatory exif tags for a new image.
+
+2004-09-01  Lutz Mueller <lutz@users.sourceforge.net>
+
        Suggestion by Angela Wrobel (http://www.wrobelnet.de/contact.html):
 
        * libexif/pentax:

diff --git a/README b/README
index 4ab86e5..cc960e4 100644 (file)
--- a/README
+++ b/README
@@ -40,6 +40,7 @@ Right now, I know of the following frontends to libexif:
  - gtkam:    A GTK+ frontend to libgphoto2 (http://www.topfrose.de).
  - thirdeye: Digital photos organizer and driver for eComStation
              (http://ecomstation.ru/thirdeye).
+ - digicam:  
 If you would like to migrate your program to use libexif or add EXIF support
 to it, don't hesitate to contact the authors.
 
@@ -56,6 +57,12 @@ libexif includes a 'libjpeg' that is 'educational code to illustrate the
 syntax of JPEG files'. Please ignore it. It is a bug that it is 
 distributed, but I think it may be useful for other people.
 
+TODO
+----
+
+We should probably support the generation of an empty EXIF structure with all
+mandatory tags. First ideas are in exif-tag.c. This has not yet been finished.
+
 AUTHORS
 -------
 

diff --git a/libexif/exif-tag.c b/libexif/exif-tag.c
index 0cc57b2..c0e256d 100644 (file)
--- a/libexif/exif-tag.c
+++ b/libexif/exif-tag.c
@@ -24,11 +24,19 @@
 
 #include <stdlib.h>
 
+typedef enum {
+       ESL_MANDATORY    = 1, /* Mandatory               */
+       ESL_CMANDATORY   = 2, /* Conditionally mandatory */
+       ESL_OPTIONAL     = 3, /* Optional                */
+       ESL_NOT_RECORDED = 4  /* Not recorded            */
+} ExifSL;                     /* Exif Support Level      */
+
 static struct {
        ExifTag tag;
        const char *name;
        const char *title;
        const char *description;
+       ExifSL esl_0[4], esl_1[4], esl_exif[4], esl_gps[4];
 } ExifTagTable[] = {
        {EXIF_TAG_INTEROPERABILITY_INDEX, "InteroperabilityIndex",
         "InteroperabilityIndex",
@@ -42,24 +50,29 @@ static struct {
        {EXIF_TAG_IMAGE_WIDTH, "ImageWidth", N_("Image Width"),
         N_("The number of columns of image data, equal to the number of "
            "pixels per row. In JPEG compressed data a JPEG marker is "
-           "used instead of this tag.")},
+           "used instead of this tag."),
+        {ESL_MANDATORY, ESL_MANDATORY, ESL_MANDATORY, ESL_NOT_RECORDED}},
        {EXIF_TAG_IMAGE_LENGTH, "ImageLength", N_("Image Length"),
         N_("The number of rows of image data. In JPEG compressed data a "
-           "JPEG marker is used instead of this tag.")},
+           "JPEG marker is used instead of this tag."), 
+        {ESL_MANDATORY, ESL_MANDATORY, ESL_MANDATORY, ESL_NOT_RECORDED}},
        {EXIF_TAG_BITS_PER_SAMPLE, "BitsPerSample", N_("Bits per Sample"),
         N_("The number of bits per image component. In this standard each "
            "component of the image is 8 bits, so the value for this "
            "tag is 9. See also <SamplesPerPixel>. In JPEG compressed data "
-           "a JPEG marker is used instead of this tag.")},
+           "a JPEG marker is used instead of this tag."),
+        {ESL_MANDATORY, ESL_MANDATORY, ESL_MANDATORY, ESL_NOT_RECORDED}},
        {EXIF_TAG_COMPRESSION, "Compression", N_("Compression"),
         N_("The compression scheme used for the image data. When a "
            "primary image is JPEG compressed, this designation is "
            "not necessary and is omitted. When thumbnails use JPEG "
-           "compression, this tag value is set to 6.")},
+           "compression, this tag value is set to 6."),
+        {ESL_MANDATORY, ESL_MANDATORY, ESL_MANDATORY, ESL_NOT_RECORDED}},
        {EXIF_TAG_PHOTOMETRIC_INTERPRETATION, "PhotometricInterpretation",
         N_("Photometric Interpretation"),
         N_("The pixel composition. In JPEG compressed data a JPEG "
-           "marker is used instead of this tag.")},
+           "marker is used instead of this tag."),
+        {ESL_MANDATORY, ESL_MANDATORY, ESL_MANDATORY, ESL_NOT_RECORDED}},
        {EXIF_TAG_FILL_ORDER, "FillOrder", N_("Fill Order"), ""},
        {EXIF_TAG_DOCUMENT_NAME, "DocumentName", N_("Document Name"), ""},
        {EXIF_TAG_IMAGE_DESCRIPTION, "ImageDescription",
@@ -68,26 +81,31 @@ static struct {
            "a comment such as \"1988 company picnic\" or "
            "the like. Two-bytes character codes cannot be used. "
            "When a 2-bytes code is necessary, the Exif Private tag "
-           "<UserComment> is to be used.")},
+           "<UserComment> is to be used."),
+        {ESL_CMANDATORY, ESL_CMANDATORY, ESL_CMANDATORY, ESL_CMANDATORY}},
        {EXIF_TAG_MAKE, "Make", N_("Manufacturer"),
         N_("The manufacturer of the recording "
            "equipment. This is the manufacturer of the DSC, scanner, "
            "video digitizer or other equipment that generated the "
            "image. When the field is left blank, it is treated as "
-           "unknown.")},
+           "unknown."),
+        {ESL_CMANDATORY, ESL_CMANDATORY, ESL_CMANDATORY, ESL_CMANDATORY}},
        {EXIF_TAG_MODEL, "Model", N_("Model"),
         N_("The model name or model number of the equipment. This is the "
            "model name or number of the DSC, scanner, video digitizer "
            "or other equipment that generated the image. When the field "
-           "is left blank, it is treated as unknown.")},
+           "is left blank, it is treated as unknown."),
+        {ESL_CMANDATORY, ESL_CMANDATORY, ESL_CMANDATORY, ESL_CMANDATORY}},
        {EXIF_TAG_STRIP_OFFSETS, "StripOffsets", N_("Strip Offsets"),
         N_("For each strip, the byte offset of that strip. It is "
            "recommended that this be selected so the number of strip "
            "bytes does not exceed 64 Kbytes. With JPEG compressed "
            "data this designation is not needed and is omitted. See also "
-           "<RowsPerStrip> and <StripByteCounts>.")},
+           "<RowsPerStrip> and <StripByteCounts>."),
+        {ESL_CMANDATORY, ESL_CMANDATORY, ESL_CMANDATORY, ESL_CMANDATORY}},
        {EXIF_TAG_ORIENTATION, "Orientation", N_("Orientation"),
-        N_("The image orientation viewed in terms of rows and columns.")},
+        N_("The image orientation viewed in terms of rows and columns."),
+        {ESL_CMANDATORY, ESL_CMANDATORY, ESL_CMANDATORY, ESL_CMANDATORY}},
        {EXIF_TAG_SAMPLES_PER_PIXEL, "SamplesPerPixel",
         N_("Samples per Pixel"),
         N_("The number of components per pixel. Since this standard applies "