* Added options -pp and -ep to list and extract preview images

* #584: Implemented missing member function
* API change, class PreviewImage: Added members to access all preview properties
* Minor fix: Suppress XMP encoding error when XMP is not enabled.

src/actions.cpp

@@ -51,6 +51,7 @@ EXIV2_RCSID("@(#) $Id$")
 #include "canonmn.hpp"
 #include "iptc.hpp"
 #include "xmp.hpp"
+#include "preview.hpp"
 #include "futils.hpp"
 #include "i18n.h"                // NLS support.
 
@@ -228,6 +229,7 @@ namespace Action {
         case Params::pmIptc:        rc = printIptc(); break;
         case Params::pmXmp:         rc = printXmp(); break;
         case Params::pmComment:     rc = printComment(); break;
+        case Params::pmPreview:     rc = printPreviewList(); break;
         }
         return rc;
     }
@@ -770,7 +772,7 @@ namespace Action {
         }
         Exiv2::IptcData::const_iterator end = iptcData.end();
         Exiv2::IptcData::const_iterator md;
-        bool manyFiles = Params::instance().files_.size() > 1;
+        bool const manyFiles = Params::instance().files_.size() > 1;
         for (md = iptcData.begin(); md != end; ++md) {
             std::cout << std::setfill(' ') << std::left;
             if (manyFiles) {
@@ -808,7 +810,7 @@ namespace Action {
         }
         Exiv2::XmpData::const_iterator end = xmpData.end();
         Exiv2::XmpData::const_iterator md;
-        bool manyFiles = Params::instance().files_.size() > 1;
+        bool const manyFiles = Params::instance().files_.size() > 1;
         for (md = xmpData.begin(); md != end; ++md) {
             std::cout << std::setfill(' ') << std::left;
             if (manyFiles) {
@@ -845,6 +847,36 @@ namespace Action {
         return 0;
     } // Print::printComment
 
+    int Print::printPreviewList()
+    {
+        if (!Exiv2::fileExists(path_, true)) {
+            std::cerr << path_
+                      << ": " << _("Failed to open the file\n");
+            return -1;
+        }
+        Exiv2::Image::AutoPtr image = Exiv2::ImageFactory::open(path_);
+        assert(image.get() != 0);
+        image->readMetadata();
+        bool const manyFiles = Params::instance().files_.size() > 1;
+        int cnt = 0;
+        Exiv2::PreviewManager pm(*image);
+        Exiv2::PreviewPropertiesList list = pm.getPreviewProperties();
+        for (Exiv2::PreviewPropertiesList::const_iterator pos = list.begin(); pos != list.end(); ++pos) {
+            if (manyFiles) {
+                std::cout << std::setfill(' ') << std::left << std::setw(20)
+                          << path_ << "  ";
+            }
+            std::cout << _("Preview") << " " << ++cnt << ": "
+                      << pos->mimeType_ << ", ";
+            if (pos->width_ != 0 && pos->height_ != 0) {
+                std::cout << pos->width_ << "x" << pos->height_ << " "
+                          << _("pixels") << ", ";
+            }
+            std::cout << pos->size_ << " " << _("bytes") << "\n";
+        }
+        return 0;
+    } // Print::printPreviewList
+
     Print::AutoPtr Print::clone() const
     {
         return AutoPtr(clone_());
@@ -1061,8 +1093,12 @@ namespace Action {
             if (dontOverwrite(xmpPath)) return 0;
             rc = metacopy(path_, xmpPath, Exiv2::ImageType::xmp, false);
         }
+        if (Params::instance().target_ & Params::ctPreview) {
+            rc = writePreviews();
+        }
         if (   !(Params::instance().target_ & Params::ctXmpSidecar)
-            && !(Params::instance().target_ & Params::ctThumb)) {
+            && !(Params::instance().target_ & Params::ctThumb)
+            && !(Params::instance().target_ & Params::ctPreview)) {
             std::string exvPath = newFilePath(path_, ".exv");
             if (dontOverwrite(exvPath)) return 0;
             rc = metacopy(path_, exvPath, Exiv2::ImageType::exv, false);
@@ -1118,6 +1154,61 @@ namespace Action {
         return rc;
     } // Extract::writeThumbnail
 
+    int Extract::writePreviews() const
+    {
+        if (!Exiv2::fileExists(path_, true)) {
+            std::cerr << path_
+                      << ": " << _("Failed to open the file\n");
+            return -1;
+        }
+        Exiv2::Image::AutoPtr image = Exiv2::ImageFactory::open(path_);
+        assert(image.get() != 0);
+        image->readMetadata();
+
+        Exiv2::PreviewManager pvMgr(*image);
+        Exiv2::PreviewPropertiesList pvList = pvMgr.getPreviewProperties();
+
+        const Params::PreviewNumbers& numbers = Params::instance().previewNumbers_;
+        for (Params::PreviewNumbers::const_iterator n = numbers.begin(); n != numbers.end(); ++n) {
+            if (*n == 0) {
+                // Write all previews
+                for (int num = 0; num < static_cast<int>(pvList.size()); ++num) {
+                    writePreviewFile(pvMgr.getPreviewImage(pvList[num]), num + 1);
+                }
+                break;
+            }
+            if (*n > static_cast<int>(pvList.size())) {
+                std::cerr << path_ << ": " << _("Image does not have preview")
+                          << " " << *n << "\n";
+                continue;
+            }
+            writePreviewFile(pvMgr.getPreviewImage(pvList[*n - 1]), *n);
+        }
+        return 0;
+    } // Extract::writePreviews
+
+    void Extract::writePreviewFile(const Exiv2::PreviewImage& pvImg, int num) const
+    {
+        std::string pvFile = newFilePath(path_, "-preview") + Exiv2::toString(num);
+        std::string pvPath = pvFile + pvImg.extension();
+        if (dontOverwrite(pvPath)) return;
+        if (Params::instance().verbose_) {
+            std::cout << _("Writing preview") << " " << num << " ("
+                      << pvImg.mimeType() << ", ";
+            if (pvImg.width() != 0 && pvImg.height() != 0) {
+                std::cout << pvImg.width() << "x" << pvImg.height() << " "
+                          << _("pixels") << ", ";
+            }
+            std::cout << pvImg.size() << " " << _("bytes") << ") "
+                      << _("to file") << " " << pvPath << std::endl;
+        }
+        long rc = pvImg.writeFile(pvFile);
+        if (rc == 0) {
+            std::cerr << path_ << ": " << _("Image does not have preview")
+                      << " " << num << "\n";
+        }
+    } // Extract::writePreviewFile
+
     Extract::AutoPtr Extract::clone() const
     {
         return AutoPtr(clone_());

src/actions.hpp

@@ -48,6 +48,7 @@
 namespace Exiv2 {
     class ExifData;
     class Image;
+    class PreviewImage;
 }
 
 // *****************************************************************************
@@ -162,6 +163,8 @@ namespace Action {
 
         //! Print the Jpeg comment
         int printComment();
+        //! Print list of available preview images
+        int printPreviewList();
         //! Print uninterpreted Iptc information
         int printIptc();
         //! print uninterpreted XMP information
@@ -278,6 +281,17 @@ namespace Action {
                  on the format of the Exif thumbnail image.
          */
         int writeThumbnail() const;
+        /*!
+          @brief Write preview images to files.
+         */
+        int writePreviews() const;
+        /*!
+          @brief Write one preview image to a file. The filename is composed by
+                 removing the suffix from the image filename and appending
+                 "-preview<num>" and the appropriate suffix (".jpg" or ".tif"),
+                 depending on the format of the Exif thumbnail image.
+         */
+        void writePreviewFile(const Exiv2::PreviewImage& pvImg, int num) const;
 
     private:
         virtual Extract* clone_() const;

src/exiv2.1

@@ -3,7 +3,7 @@
 .\" First parameter, NAME, should be all caps
 .\" Second parameter, SECTION, should be 1-8, maybe w/ subsection
 .\" other parameters are allowed: see man(7), man(1)
-.TH EXIV2 1 "Sept 10th, 2008"
+.TH EXIV2 1 "Dec 7th, 2008"
 .\" Please adjust this date whenever revising the manpage.
 .\"
 .\" Some roff macros, for reference:
@@ -152,6 +152,8 @@ i : IPTC data values
 x : XMP properties
 .br
 c : JPEG comment
+.br
+p : list available image previews, sorted by preview image size in pixels
 .TP
 .B \-P \fIcols\fP
 Print columns for the Exif taglist ('print' action), allows detailed
@@ -209,7 +211,13 @@ be named \fIfile\fP\-thumb.jpg.
 .TP
 .B \-e \fItgt\fP
 Extract target(s) for the 'extract' action. Possible targets are the same 
-as those for the \fB\-d\fP option, plus a modifier:
+as those for the \fB\-d\fP option, plus a target to extract preview
+images and a modifier to generate an XMP sidecar file:
+.br
+p[<n>[,<m> ...]] : Extract preview images. The optional comma separated
+list of preview image numbers is used to determine which preview images
+to extract. The available preview images and their numbers are displayed
+with the 'print' option -pp.
 .br
 X : Extract metadata to an XMP sidecar file <file>.xmp. The remaining
 extract targets determine what metadata to extract to the sidecar
@@ -363,6 +371,10 @@ exiv2 \-it img1.jpg img2.jpg
 Inserts (copies) metadata from img1.exv to img1.jpg and from img2.exv
 to img2.jpg.
 .TP
+exiv2 \-ep1,2 image.jpg
+Extracts previews 1 and 2 from the image to the files image\-preview1.jpg
+and image\-preview2.jpg.
+.TP
 exiv2 \-eiX image.jpg 
 Extracts IPTC datasets into an XMP sidecar file image.xmp and in the
 process converts them to "IPTC Core" XMP schema.

src/exiv2.cpp

@@ -19,7 +19,7 @@
  * Foundation, Inc., 51 Franklin Street, 5th Floor, Boston, MA 02110-1301 USA.
  */
 /*
-  Abstract:  Command line program to display and manipulate image %Exif data
+  Abstract:  Command line program to display and manipulate image metadata.
 
   File:      exiv2.cpp
   Version:   $Rev$
@@ -50,6 +50,7 @@ EXIV2_RCSID("@(#) $Id$")
 #include <iomanip>
 #include <cstring>
 #include <cassert>
+#include <cctype>
 
 // *****************************************************************************
 // local declarations
@@ -80,6 +81,17 @@ namespace {
     int parseCommonTargets(const std::string& optarg,
                            const std::string& action);
 
+    /*! 
+      @brief Parse numbers separated by commas into container
+      @param previewNumbers Container for the numbers
+      @param optarg Option arguments
+      @param j Starting index into optarg
+      @return Number of characters processed
+     */
+    int parsePreviewNumbers(Params::PreviewNumbers& previewNumbers,
+                            const std::string& optarg,
+                            int j);
+
     /*!
       @brief Parse metadata modification commands from multiple files
       @param modifyCmds Reference to a structure to store the parsed commands
@@ -257,6 +269,7 @@ void Params::help(std::ostream& os) const
        << _("             i : IPTC data values\n")
        << _("             x : XMP properties\n")
        << _("             c : JPEG comment\n")
+       << _("             p : list available previews\n")
        << _("   -P cols Print columns for the Exif taglist ('print' action). Valid are:\n")
        << _("             x : print a column with the tag value\n")
        << _("             g : group name\n")
@@ -282,7 +295,9 @@ void Params::help(std::ostream& os) const
             "           Only JPEG thumbnails can be inserted, they need to be named\n"
             "           <file>-thumb.jpg\n")
        << _("   -e tgt  Extract target(s) for the 'extract' action. Possible targets\n"
-            "           are the same as those for the -d option, plus a modifier:\n"
+            "           are the same as those for the -d option, plus a target to extract\n"
+            "           preview images and a modifier to generate an XMP sidecar file:\n"
+            "             p[<n>[,<m> ...]] : Extract preview images.\n"
             "             X : Extract metadata to an XMP sidecar file <file>.xmp\n")
        << _("   -r fmt  Filename format for the 'rename' action. The format string\n"
             "           follows strftime(3). The following keywords are supported:\n")
@@ -457,6 +472,7 @@ int Params::evalPrint(const std::string& optarg)
         case 'i': printMode_ = pmIptc; break;
         case 'x': printMode_ = pmXmp; break;
         case 'c': printMode_ = pmComment; break;
+        case 'p': printMode_ = pmPreview; break;
         default:
             std::cerr << progname() << ": " << _("Unrecognized print mode") << " `"
                       << optarg << "'\n";
@@ -850,6 +866,15 @@ namespace {
                 target |= Params::ctXmpSidecar;
                 if (optarg == "X") target |= Params::ctExif | Params::ctIptc | Params::ctXmp;
                 break;
+            case 'p':
+            {
+                if (strcmp(action.c_str(), "extract") == 0) {
+                    i += parsePreviewNumbers(Params::instance().previewNumbers_, optarg, i + 1);
+                    target |= Params::ctPreview;
+                    break;
+                }
+                // fallthrough
+            }
             default:
                 std::cerr << Params::instance().progname() << ": " << _("Unrecognized ")
                           << action << " " << _("target") << " `"  << optarg[i] << "'\n";
@@ -860,6 +885,46 @@ namespace {
         return rc ? rc : target;
     } // parseCommonTargets
 
+    int parsePreviewNumbers(Params::PreviewNumbers& previewNumbers,
+                            const std::string& optarg,
+                            int j)
+    {
+        size_t k = j;
+        for (size_t i = j; i < optarg.size(); ++i) {
+            std::ostringstream os;
+            for (k = i; k < optarg.size() && isdigit(optarg[k]); ++k) {
+                os << optarg[k];
+            }
+            if (k > i) {
+                bool ok = false;
+                int num = Exiv2::stringTo<int>(os.str(), ok);
+                if (ok && num >= 0) {
+                    previewNumbers.insert(num);
+                }
+                else {
+                    std::cerr << Params::instance().progname() << ": "
+                              << _("Invalid preview number") << ": " << num << "\n";
+                }
+                i = k;
+            }
+            if (!(k < optarg.size() && optarg[i] == ',')) break;
+        }
+        int ret = static_cast<int>(k - j);
+        if (ret == 0) {
+            previewNumbers.insert(0);
+        }
+#ifdef DEBUG
+        std::cout << "\nThe set now contains: ";
+        for (Params::PreviewNumbers::const_iterator i = previewNumbers.begin();
+             i != previewNumbers.end();
+             ++i) {
+            std::cout << *i << ", ";
+        }
+        std::cout << std::endl;
+#endif
+        return k - j;
+    } // parsePreviewNumbers
+
     bool parseCmdFiles(ModifyCmds& modifyCmds,
                        const Params::CmdFiles& cmdFiles)
     {

src/exiv2.hpp

@@ -37,6 +37,7 @@
 // + standard includes
 #include <string>
 #include <vector>
+#include <set>
 #include <iostream>
 
 // *****************************************************************************
@@ -72,7 +73,7 @@ struct CmdIdAndString {
   @brief Implements the command line handling for the program.
 
   Derives from Util::Getopt to use the command line argument parsing
-  functionalty provided there. This class is implemented as a Singleton,
+  functionality provided there. This class is implemented as a singleton,
   i.e., there is only one global instance of it, which can be accessed
   from everywhere.
 
@@ -113,6 +114,8 @@ public:
     typedef std::vector<std::string> CmdLines;
     //! Container to store filenames.
     typedef std::vector<std::string> Files;
+    //! Container for preview image numbers
+    typedef std::set<int> PreviewNumbers;
 
     /*!
       @brief Controls all access to the global Params instance.
@@ -123,7 +126,7 @@ public:
     void cleanup();
 
     //! Enumerates print modes
-    enum PrintMode { pmSummary, pmList, pmIptc, pmXmp, pmComment };
+    enum PrintMode { pmSummary, pmList, pmIptc, pmXmp, pmComment, pmPreview };
 
     //! Individual items to print
     enum PrintItem {
@@ -147,7 +150,8 @@ public:
         ctComment    =  4,
         ctThumb      =  8,
         ctXmp        = 16,
-        ctXmpSidecar = 32
+        ctXmpSidecar = 32,
+        ctPreview    = 64
     };
 
     //! Enumerates the policies to handle existing files in rename action
@@ -191,6 +195,7 @@ public:
     std::string directory_;             //!< Location for files to extract/insert
     std::string suffix_;                //!< File extension of the file to insert
     Files files_;                       //!< List of non-option arguments.
+    PreviewNumbers previewNumbers_;     //!< List of preview numbers
 
 private:
     //! Pointer to the global Params object.

src/jp2image.cpp

@@ -490,7 +490,7 @@ namespace Exiv2
 
                     if (writeXmpFromPacket() == false)
                     {
-                        if (XmpParser::encode(xmpPacket_, xmpData_))
+                        if (XmpParser::encode(xmpPacket_, xmpData_) > 1)
                         {
 #ifndef SUPPRESS_WARNINGS
                             std::cerr << "Error: Failed to encode XMP metadata.\n";

src/jpgimage.cpp

@@ -633,7 +633,7 @@ namespace Exiv2 {
                     }
                 }
                 if (writeXmpFromPacket() == false) {
-                    if (XmpParser::encode(xmpPacket_, xmpData_)) {
+                    if (XmpParser::encode(xmpPacket_, xmpData_) > 1) {
 #ifndef SUPPRESS_WARNINGS
                         std::cerr << "Error: Failed to encode XMP metadata.\n";
 #endif

src/pngimage.cpp

@@ -309,7 +309,7 @@ namespace Exiv2 {
 
                 if (writeXmpFromPacket() == false)
                 {
-                    if (XmpParser::encode(xmpPacket_, xmpData_))
+                    if (XmpParser::encode(xmpPacket_, xmpData_) > 1)
                     {
 #ifndef SUPPRESS_WARNINGS
                         std::cerr << "Error: Failed to encode XMP metadata.\n";

src/preview.cpp

@@ -695,6 +695,16 @@ namespace Exiv2 {
         return DataBuf(pData_, size_);
     }
 
+    const byte* PreviewImage::pData() const
+    {
+        return pData_;
+    }
+
+    uint32_t PreviewImage::size() const
+    {
+        return size_;
+    }
+
     std::string PreviewImage::mimeType() const
     {
         return properties_.mimeType_;
@@ -705,9 +715,19 @@ namespace Exiv2 {
         return properties_.extension_;
     }
 
-    uint32_t PreviewImage::size() const
+    uint32_t PreviewImage::width() const
     {
-        return size_;
+        return properties_.width_;
+    }
+
+    uint32_t PreviewImage::height() const
+    {
+        return properties_.height_;
+    }
+
+    PreviewId PreviewImage::id() const
+    {
+        return properties_.id_;
     }
 
     PreviewManager::PreviewManager(const Image& image)

src/preview.hpp

@@ -100,6 +100,10 @@ namespace Exiv2 {
           @brief Return a pointer to the image data for read-only access.
          */
         const byte* pData() const;
+        /*!
+          @brief Return the size of the preview image in bytes.
+         */
+        uint32_t size() const;
         /*!
           @brief Write the thumbnail image to a file.
 
@@ -122,9 +126,17 @@ namespace Exiv2 {
          */
         std::string extension() const;
         /*!
-          @brief Return the size of the preview image in bytes.
+          @brief Return the width of the preview image in pixels.
-         */
+        */
-        uint32_t size() const;
+        uint32_t width() const;
+        /*!
+          @brief Return the height of the preview image in pixels.
+        */
+        uint32_t height() const;
+        /*!
+          @brief Return the preview image type identifier.
+        */
+        PreviewId id() const;
         //@}
 
     private:

src/tiffvisitor.cpp

@@ -477,7 +477,7 @@ namespace Exiv2 {
             exifData_.erase(pos);
         }
         std::string xmpPacket;
-        if (XmpParser::encode(xmpPacket, xmpData_)) {
+        if (XmpParser::encode(xmpPacket, xmpData_) > 1) {
 #ifndef SUPPRESS_WARNINGS
             std::cerr << "Error: Failed to encode XMP metadata.\n";
 #endif

src/xmpsidecar.cpp

@@ -119,7 +119,7 @@ namespace Exiv2 {
             copyExifToXmp(exifData_, xmpData_);
             copyIptcToXmp(iptcData_, xmpData_);
             if (XmpParser::encode(xmpPacket_, xmpData_,
-                                  XmpParser::omitPacketWrapper|XmpParser::useCompactFormat)) {
+                                  XmpParser::omitPacketWrapper|XmpParser::useCompactFormat) > 1) {
 #ifndef SUPPRESS_WARNINGS
                 std::cerr << "Error: Failed to encode XMP metadata.\n";
 #endif