Gdiplus [53]: image (5) attributes of images (image metadata)

Related methods and attributes:

Igpimage. getpropertyitem (); {Get attribute item} igpimage. setpropertyitem (); {set attribute item} igpimage. removepropertyitem (); {Delete attribute item} igpimage. propertyidlist; {Get image attribute ID array} igpimage. propertyitems; {retrieving image attribute sets}
 

Igpimage. propertyitems points to an igppropertyitems array;
Igppropertyitem is an attribute (or attribute) in the igppropertyitems attribute array ).

Each attribute item contains:

Igppropertyitem. ID; {property ID, that is, property category, for example, title or copyright} igppropertyitem. valuetype; {attribute data type} igppropertyitem. length; {attribute data length} igppropertyitem. value; {Attribute Data Pointer}
 

Igpimage. propertyidlist is only an array for retrieving attribute IDs.

Igppropertyitem. valuetype constant:

Propertytagtypebyte = 1; {byte array} propertytagtypeascii = 2; {pansichar} bytes = 3; {word} propertytagtypelong = 4; {Cardinal} propertytagtyperational = 5; {Cardinal/Cardinal; the first number is numerator, and the second number is denominator} propertytagtypeundefined = 7; {A byte array that can contain any data type} propertytagtypeslong = 9; {INTEGER} propertytagtypesrational = 10; {INTEGER/Integer; the first number is the numerator, and the second number is the denominator}
 

Igppropertyitem. ID constant:

PropertyTagGpsVer                         = $0000PropertyTagGpsLatitudeRef                 = $0001PropertyTagGpsLatitude                    = $0002PropertyTagGpsLongitudeRef                = $0003PropertyTagGpsLongitude                   = $0004PropertyTagGpsAltitudeRef                 = $0005PropertyTagGpsAltitude                    = $0006PropertyTagGpsGpsTime                     = $0007PropertyTagGpsGpsSatellites               = $0008PropertyTagGpsGpsStatus                   = $0009PropertyTagGpsGpsMeasureMode              = $000APropertyTagGpsGpsDop                      = $000BPropertyTagGpsSpeedRef                    = $000CPropertyTagGpsSpeed                       = $000DPropertyTagGpsTrackRef                    = $000EPropertyTagGpsTrack                       = $000FPropertyTagGpsImgDirRef                   = $0010PropertyTagGpsImgDir                      = $0011PropertyTagGpsMapDatum                    = $0012PropertyTagGpsDestLatRef                  = $0013PropertyTagGpsDestLat                     = $0014PropertyTagGpsDestLongRef                 = $0015PropertyTagGpsDestLong                    = $0016PropertyTagGpsDestBearRef                 = $0017PropertyTagGpsDestBear                    = $0018PropertyTagGpsDestDistRef                 = $0019PropertyTagGpsDestDist                    = $001APropertyTagNewSubfileType                 = $00FEPropertyTagSubfileType                    = $00FFPropertyTagImageWidth                     = $0100PropertyTagImageHeight                    = $0101PropertyTagBitsPerSample                  = $0102PropertyTagCompression                    = $0103PropertyTagPhotometricInterp              = $0106PropertyTagThreshHolding                  = $0107PropertyTagCellWidth                      = $0108PropertyTagCellHeight                     = $0109PropertyTagFillOrder                      = $010APropertyTagDocumentName                   = $010DPropertyTagImageDescription               = $010EPropertyTagEquipMake                      = $010FPropertyTagEquipModel                     = $0110PropertyTagStripOffsets                   = $0111PropertyTagOrientation                    = $0112PropertyTagSamplesPerPixel                = $0115PropertyTagRowsPerStrip                   = $0116PropertyTagStripBytesCount                = $0117PropertyTagMinSampleValue                 = $0118PropertyTagMaxSampleValue                 = $0119PropertyTagXResolution                    = $011APropertyTagYResolution                    = $011BPropertyTagPlanarConfig                   = $011CPropertyTagPageName                       = $011DPropertyTagXPosition                      = $011EPropertyTagYPosition                      = $011FPropertyTagFreeOffset                     = $0120PropertyTagFreeByteCounts                 = $0121PropertyTagGrayResponseUnit               = $0122PropertyTagGrayResponseCurve              = $0123PropertyTagT4Option                       = $0124PropertyTagT6Option                       = $0125PropertyTagResolutionUnit                 = $0128PropertyTagPageNumber                     = $0129PropertyTagTransferFunction               = $012DPropertyTagSoftwareUsed                   = $0131PropertyTagDateTime                       = $0132PropertyTagArtist                         = $013BPropertyTagHostComputer                   = $013CPropertyTagPredictor                      = $013DPropertyTagWhitePoint                     = $013EPropertyTagPrimaryChromaticities          = $013FPropertyTagColorMap                       = $0140PropertyTagHalftoneHints                  = $0141PropertyTagTileWidth                      = $0142PropertyTagTileLength                     = $0143PropertyTagTileOffset                     = $0144PropertyTagTileByteCounts                 = $0145PropertyTagInkSet                         = $014CPropertyTagInkNames                       = $014DPropertyTagNumberOfInks                   = $014EPropertyTagDotRange                       = $0150PropertyTagTargetPrinter                  = $0151PropertyTagExtraSamples                   = $0152PropertyTagSampleFormat                   = $0153PropertyTagSMinSampleValue                = $0154PropertyTagSMaxSampleValue                = $0155PropertyTagTransferRange                  = $0156PropertyTagJPEGProc                       = $0200PropertyTagJPEGInterFormat                = $0201PropertyTagJPEGInterLength                = $0202PropertyTagJPEGRestartInterval            = $0203PropertyTagJPEGLosslessPredictors         = $0205PropertyTagJPEGPointTransforms            = $0206PropertyTagJPEGQTables                    = $0207PropertyTagJPEGDCTables                   = $0208PropertyTagJPEGACTables                   = $0209PropertyTagYCbCrCoefficients              = $0211PropertyTagYCbCrSubsampling               = $0212PropertyTagYCbCrPositioning               = $0213PropertyTagREFBlackWhite                  = $0214PropertyTagGamma                          = $0301PropertyTagICCProfileDescriptor           = $0302PropertyTagSRGBRenderingIntent            = $0303PropertyTagImageTitle                     = $0320PropertyTagResolutionXUnit                = $5001PropertyTagResolutionYUnit                = $5002PropertyTagResolutionXLengthUnit          = $5003PropertyTagResolutionYLengthUnit          = $5004PropertyTagPrintFlags                     = $5005PropertyTagPrintFlagsVersion              = $5006PropertyTagPrintFlagsCrop                 = $5007PropertyTagPrintFlagsBleedWidth           = $5008PropertyTagPrintFlagsBleedWidthScale      = $5009PropertyTagHalftoneLPI                    = $500APropertyTagHalftoneLPIUnit                = $500BPropertyTagHalftoneDegree                 = $500CPropertyTagHalftoneShape                  = $500DPropertyTagHalftoneMisc                   = $500EPropertyTagHalftoneScreen                 = $500FPropertyTagJPEGQuality                    = $5010PropertyTagGridSize                       = $5011PropertyTagThumbnailFormat                = $5012PropertyTagThumbnailWidth                 = $5013PropertyTagThumbnailHeight                = $5014PropertyTagThumbnailColorDepth            = $5015PropertyTagThumbnailPlanes                = $5016PropertyTagThumbnailRawBytes              = $5017PropertyTagThumbnailSize                  = $5018PropertyTagThumbnailCompressedSize        = $5019PropertyTagColorTransferFunction          = $501APropertyTagThumbnailData                  = $501BPropertyTagThumbnailImageWidth            = $5020PropertyTagThumbnailImageHeight           = $5021PropertyTagThumbnailBitsPerSample         = $5022PropertyTagThumbnailCompression           = $5023PropertyTagThumbnailPhotometricInterp     = $5024PropertyTagThumbnailImageDescription      = $5025PropertyTagThumbnailEquipMake             = $5026PropertyTagThumbnailEquipModel            = $5027PropertyTagThumbnailStripOffsets          = $5028PropertyTagThumbnailOrientation           = $5029PropertyTagThumbnailSamplesPerPixel       = $502APropertyTagThumbnailRowsPerStrip          = $502BPropertyTagThumbnailStripBytesCount       = $502CPropertyTagThumbnailResolutionX           = $502DPropertyTagThumbnailResolutionY           = $502EPropertyTagThumbnailPlanarConfig          = $502FPropertyTagThumbnailResolutionUnit        = $5030PropertyTagThumbnailTransferFunction      = $5031PropertyTagThumbnailSoftwareUsed          = $5032PropertyTagThumbnailDateTime              = $5033PropertyTagThumbnailArtist                = $5034PropertyTagThumbnailWhitePoint            = $5035PropertyTagThumbnailPrimaryChromaticities = $5036PropertyTagThumbnailYCbCrCoefficients     = $5037PropertyTagThumbnailYCbCrSubsampling      = $5038PropertyTagThumbnailYCbCrPositioning      = $5039PropertyTagThumbnailRefBlackWhite         = $503APropertyTagThumbnailCopyRight             = $503BPropertyTagLuminanceTable                 = $5090PropertyTagChrominanceTable               = $5091PropertyTagFrameDelay                     = $5100PropertyTagLoopCount                      = $5101PropertyTagGlobalPalette                  = $5102PropertyTagIndexBackground                = $5103PropertyTagIndexTransparent               = $5104PropertyTagPixelUnit                      = $5110PropertyTagPixelPerUnitX                  = $5111PropertyTagPixelPerUnitY                  = $5112PropertyTagPaletteHistogram               = $5113PropertyTagCopyright                      = $8298PropertyTagExifExposureTime               = $829APropertyTagExifFNumber                    = $829DPropertyTagExifIFD                        = $8769PropertyTagICCProfile                     = $8773PropertyTagExifExposureProg               = $8822PropertyTagExifSpectralSense              = $8824PropertyTagGpsIFD                         = $8825PropertyTagExifISOSpeed                   = $8827PropertyTagExifOECF                       = $8828PropertyTagExifVer                        = $9000PropertyTagExifDTOrig                     = $9003PropertyTagExifDTDigitized                = $9004PropertyTagExifCompConfig                 = $9101PropertyTagExifCompBPP                    = $9102PropertyTagExifShutterSpeed               = $9201PropertyTagExifAperture                   = $9202PropertyTagExifBrightness                 = $9203PropertyTagExifExposureBias               = $9204PropertyTagExifMaxAperture                = $9205PropertyTagExifSubjectDist                = $9206PropertyTagExifMeteringMode               = $9207PropertyTagExifLightSource                = $9208PropertyTagExifFlash                      = $9209PropertyTagExifFocalLength                = $920APropertyTagExifMakerNote                  = $927CPropertyTagExifUserComment                = $9286PropertyTagExifDTSubsec                   = $9290PropertyTagExifDTOrigSS                   = $9291PropertyTagExifDTDigSS                    = $9292PropertyTagExifFPXVer                     = $A000PropertyTagExifColorSpace                 = $A001PropertyTagExifPixXDim                    = $A002PropertyTagExifPixYDim                    = $A003PropertyTagExifRelatedWav                 = $A004PropertyTagExifInterop                    = $A005PropertyTagExifFlashEnergy                = $A20BPropertyTagExifSpatialFR                  = $A20CPropertyTagExifFocalXRes                  = $A20EPropertyTagExifFocalYRes                  = $A20FPropertyTagExifFocalResUnit               = $A210PropertyTagExifSubjectLoc                 = $A214PropertyTagExifExposureIndex              = $A215PropertyTagExifSensingMethod              = $A217PropertyTagExifFileSource                 = $A300PropertyTagExifSceneType                  = $A301PropertyTagExifCfaPattern                 = $A302
 

Traversal property:

uses GdiPlus;procedure TForm1.Button1Click(Sender: TObject);var  Image: IGPImage;  PropertyItem: IGPPropertyItem;begin  Image := TGPImage.Create('C:\GdiPlusImg\FakePhoto.jpg');  Memo1.Clear;  for PropertyItem in Image.PropertyItems do with Memo1.Lines do  begin    Add(Format('Id: $%.4x', [PropertyItem.Id]));    Add(Format('ValueType: %d', [PropertyItem.ValueType]));    Add(Format('Length: %d', [PropertyItem.Length]));    Add(Format('Value: $%p', [PropertyItem.Value]));    Add(EmptyStr);  end;end;
 

Traverse only the property ID:

uses GdiPlus;procedure TForm1.Button1Click(Sender: TObject);var  Image: IGPImage;  PropID: Cardinal;begin  Image := TGPImage.Create('C:\GdiPlusImg\FakePhoto.jpg');  Memo1.Clear;  for PropID in Image.PropertyIdList do  begin    Memo1.Lines.Add(Format('$%.4x', [PropID]));  end;end;
 

The following example tests the setpropertyitem, getpropertyitem, and removepropertyitem methods.

The title attribute (whose ID is propertytagimagetitle) is added to the image first );
Save the image, open it again, and then read this attribute;
After deleting this property, I tried to find it...

Uses gdiplus; Procedure construct (Sender: tobject); var image: igpimage; proptitle: igppropertyitem; Title: ansistring; I: integer; begin chdir ('C: \ gdiplusimg \'); image: = tgpimage.create('fakephoto.jpg '); // Title: = 'new title'; proptitle: = tgppropertyitem. create; proptitle. ID: = propertytagimagetitle; proptitle. valuetype: = propertytagtypeascii; proptitle. length: = length (title) + 1; proptitle. value: = pansichar (title); image. setpropertyitem (proptitle); image.save('fakephoto_test.jpg ', tgpimageformat. JPEG); Image: = nil; // proptitle: = nil; Image: = tgpimage.create('fakephoto_test.jpg '); proptitle: = image. getpropertyitem (propertytagimagetitle); showmessage (pansichar (proptitle. value); {New title} // image. removepropertyitem (propertytagimagetitle); for I: = 0 to image. propertyidlist. count-1 do if image. propertyidlist [I] = propertytagimagetitle then showmessage ('Property title detected exist'); {No more deleted} end;