[magick-developers] dicom properties

[Shane Blackett]

Hi,

dicom files have many fields of metadata.  In general these are parsed 
and stored in the image properties.

Unfortunately for dicom files which contain jpeg encoded images, a 
separate image is written out and passed to the jpeg coder to read and 
all the metadata is lost.

As a simple way of maintaining this data I have delayed the destroy of 
the dicom image and read the jpeg_image into a separate variable, and 
then copied all the parameters from the dicom to the jpeg.

The patch against subversion is below if you think this is useful.

Shane.

Index: coders/dcm.c
===================================================================
--- coders/dcm.c        (revision 8485)
+++ coders/dcm.c        (working copy)
@@ -3196,6 +3196,10 @@
    if ((strcmp(transfer_syntax,"1.2.840.10008.1.2.4.50") == 0) ||
        (strcmp(transfer_syntax,"1.2.840.10008.1.2.4.70") == 0))
      {
+      const char
+        *property,
+        *property_value;
+
        char
          filename[MaxTextExtent];

@@ -3206,6 +3210,9 @@
          c,
          unique_file;

+      Image
+        *jpeg_image;
+
        ImageInfo
          *read_info;

@@ -3244,15 +3251,22 @@
          c=ReadBlobByte(image);
        }
        (void) fclose(file);
-      image=DestroyImage(image);
        read_info=CloneImageInfo(image_info);
        SetImageInfoBlob(read_info,(void *) NULL,0);
        (void) FormatMagickString(read_info->filename,MaxTextExtent,
          "jpeg:%s",filename);
-      image=ReadImage(read_info,exception);
+      jpeg_image=ReadImage(read_info,exception);
+      /* Copy dcm attributes from image to jpeg image */
+      ResetImagePropertyIterator(image);
+      while(NULL != (property = GetNextImageProperty(image)))
+      {
+        property_value = GetImageProperty(image,property);
+        (void) SetImageProperty(jpeg_image,property,property_value);
+      }
+      image=DestroyImage(image);
        (void) RelinquishUniqueFileResource(filename);
        read_info=DestroyImageInfo(read_info);
-      return(GetFirstImageInList(image));
+      return(GetFirstImageInList(jpeg_image));
      }
    scale=(Quantum *) NULL;
    if (depth != (1UL*QuantumDepth))