ImageEn

FAQ


Frequently Asked Questions about ImageEn:



After updating ImageEn I get the following error on Delphi start-up: "The procedure entry point ... could not be located in the dynamic link library DPKIECtrl26.bpl"

There are two common causes for this error:

1. You have multiple copies of the ImageEn BPL files on your system (generally error is for DPKIECtrl*.bpl)

Search your system for any PKIE*.* and DPKIE*.* files and remove them (it might help to review the library paths under Tools > Options, Library). Then reinstall ImageEn.

2. You have another package that uses the ImageEn BPL (generally error is for PKIECtrl*.bpl)

A package - either one of ImageEn's or one of your own - is trying to access PKIECtrl26.bpl, but is failing because PKIECtrl26.bpl has been recompiled more recently. The error may be followed by another one that advised you which package is giving you the error: "Xyz package could not be loaded. Would you like to load it next time you run Delphi...".

If you know which package has caused the problem, open it's DPK file and recompile it. Otherwise, go through each of your packages and recompile any that use ImageEn.


Why don't I see any Twain devices when I compile my application as 64bit?

Unfortunately, most scanner manufacturers do not offer 64bit Twain drivers. Instead, they usually include a "WIA over Twain" driver. So, you are better to use WIA instead of Twain. You can use the TIEAcquireParams class in ImageEn to provide generic access to scanner devices whether they use WIA, Twain, etc.

If you need to test 64bit Twain support, you can use the FreeImage Software scanner driver:
sourceforge.net/projects/twain-samples/files/TWAIN%202%20Sample%20Data%20Source/


How can I prevent the scrollwheel from causing the image to zoom? I want it to remain the original size at all times

You can use MouseWheelParams:

ImageEnView1.MouseWheelParams.Action := iemwNone;

Other values are iemwVScroll and iemwZoom (default).


Can I load PDF files with ImageEn?

PDF loading requires one of the following plug-ins:
◼ImageEn PDFium Plug-in from: www.imageen.com/download/
◼WPViewPDF commercial plug-in
◼ImageMagick + GhostScript


How do I convert a multi-page GIF image to TIFF format without a visual component?

There are several ways. The simplest is to use TIEMultiBitmap:

var
  mbmp: TIEMultiBitmap;
begin
  mbmp := TIEMultiBitmap.Create;
  mbmp.LoadFromFile('D:\in.gif');
  mbmp.SaveToFile('D:\out.tiff');
  mbmp.Free();
end;


How do I disable all keyboard shortcuts in ImageEn?

You need to set the following properties (which are all enabled by default):
◼Disable TImageEnView.KeyboardShortcuts
◼Remove loKeyboardShortcuts from TImageEnView.LayerOptions
◼Remove ieboEnableFileShortcuts from TImageEnFolderMView.FolderInteract
◼Disable TIERichEdit.KeyboardShortcuts
◼Disable TImageEnViewToolbar/TIERichEditToolbar.KeyboardShortcuts
◼Remove Shortcuts from any ImageEn Actions

Configure or disable individual keyboard shortcuts using KeyboardShortcuts


How can I improve the performance of TImageEnMView when I have many thumbnails?

Ensure you have optimized your settings to ensure the best performance:

Also see the Performance demo: \Demos\Multi\MViewPerformance\Performance.dpr


I've added the Plug-in DLLs to my application folder, but ImageEn does not support its formats. What do I need to do?

You can automatically register the plug-in DLLs using:

IEGlobalSettings().RegisterPlugIns();


Can your component take a series of single page TIFF files and create a Multi-Page file from them?

Yes, load each page using:

ImageEnView1.IO.LoadFromFile('C:\page1.tif');

Then set TIFF_ImageIndex and save the page:

ImageEnView1.IO.Params.TIFF_ImageIndex := 0; // increment this value for each page
ImageEnView1.IO.InsertToFileTIFF('D:\multipage.tif');

Otherwise you can use a TImageEnMView component or a TIEMultiBitmap. See the "multi" demo for more detail.


How do I change the current page of a TIFF image in TImageEnView?

There are two ways to load several pages from a TIFF:

1) Load a page at the time, using TImageEnView and TIFF_ImageIndex, e.g.

ImageEnView1.IO.Params.TIFF_ImageIndex := page_number; // where page_number is the page to load and starts from 0 (first page)
ImageEnView1.IO.LoadFromFile('mytiff.tiff');

To determine many pages there are:

page_count := EnumTIFFIm('mytiff.tiff');

2) load all pages using a TImageEnMView:

ImageEnMView1.MIO.LoadFromFile('mytiff.tiff');


How can I validate that the fonts used when loading a layer file are available on the system?

After loading an ImageEn layer file you can iterate through all of the fonts to ensure they are valid, for example:

ImageEnView1.IO.LoadFromFileIEN(...);

// Validate fonts are installed on this system
for i := 0 to ImageEnView1.LayersCount do
begin
  if ImageEnView1.Layers[i].Kind = ielkText then
    fontName := TIETextLayer( ImageEnView1.Layers[i] ).Font
  else
  if ImageEnView1.Layers[i].Kind = ielkLine then
    fontName := TIELineLayer( ImageEnView1.Layers[i] ).LabelFont
  else
    continue;

  if Screen.Fonts.IndexOf( fontName ) = -1 then
  begin
    // This font is not installed. Substitute or install it...
  end;
end;


Is it possible to convert a multipage image to a different encoding, such as G3 and G4?

Using DuplicateCompressionInfo you must change the compression property for all pages:

ImageEnMView1.MIO.LoadFromFile('original.tif');

// change compression for the first page
ImageEnMView1.MIO.Params[0].TIFF_Compression := ioTIFF_G4FAX;

// change compression for the other pages
ImageEnMView1.MIO.DuplicateCompressionInfo();

// now save
ImageEnMView1.Mio.SaveToFile('output.tif');


How can I improve performance when working with many layers?

The main performance properties are:
◼LayersCaching: Caches the view of each layer. Much faster but uses more memory.
◼LayersFastDrawing: Display quality of layers (and whether the quality view is delayed).
◼ZoomFilter/DelayZoomFilter: Display quality of images (and whether the quality view is delayed). This option is ignored if LayersFastDrawing is active
◼LayersRotationUseFilterOnPreview: Whether the quality filter (LayersRotationFilter) is previewed without applying the rotation using LayersFixRotations

Here is some example code from the Layers_AllTypes demo:

procedure Tfmain.cmbPreviewQualityChange(Sender: TObject);
const
  _cmbPreviewQuality_Fast          = 0;
  _cmbPreviewQuality_Delayed_Best  = 1;
  _cmbPreviewQuality_Best          = 2;
begin
  // Separate code to make it easier to understand

  if cmbPreviewQuality.ItemIndex = _cmbPreviewQuality_Fast then
  begin
    // FASTEST DISPLAY

    // Zoom filter
    ImageEnView1.ZoomFilter := rfNone;
    ImageEnView1.DelayZoomFilter := False;

    // Rotation anti-alias
    ImageEnView1.LayersRotationFilter := ierBicubic;

    // Fast drawing
    ImageEnView1.LayersFastDrawing := iefFast;
 end
  else
  if cmbPreviewQuality.ItemIndex = _cmbPreviewQuality_Delayed_Best then
  begin
    // DELAYED HIGH QUALITY

    // Zoom filter
    ImageEnView1.ZoomFilter := rfLanczos3;
    ImageEnView1.DelayZoomFilter := True;

    // Rotation anti-alias
    ImageEnView1.LayersRotationFilter := ierBicubic;

    // Fast drawing
    ImageEnView1.LayersFastDrawing := iefDelayed;
  end
  else
  begin
    // HIGH QUALITY

    // Zoom filter
    ImageEnView1.ZoomFilter := rfLanczos3;
    ImageEnView1.DelayZoomFilter := False;

    // Rotation anti-alias
    ImageEnView1.LayersRotationFilter := ierBicubic;

    // Fast drawing
    ImageEnView1.LayersFastDrawing := iefNormal;
  end;

  ImageEnView1.Update();
end;

procedure Tfmain.chkLayerCachingClick(Sender: TObject);
begin
  if chkLayerCaching.Checked then
    ImageEnView1.LayersCaching := -1
  else
    ImageEnView1.LayersCaching := 0;
end;


Using TImageEnMView, how do I load images as they are displayed?

There are several ways to display images "on demand":

1) If you have a folder containing your images, use FillFromDirectory:

ImageEnMView1.FillFromDirectory('c:\myimages');

2) When you add a new image just set its ImageFileName[], and ImageEn will automatically load the specified file when needed. For example:

idx := ImageEnMView1.AppendImage;
ImageEnMView1.ImageFileName[idx] := 'first.jpg';

3) When you add a new image just set the ImageID[] property. You must create an array of filenames where images are to be loaded. For example:

var
  files: array [0..1] of string;
begin
  files[0] := 'first.jpg';
  files[1] := 'second.jpg';
  ImageEnMView1.ImageID[ ImageEnMView1.AppendImage ] := 0;
  ImageEnMView1.ImageID[ ImageEnMView1.AppendImage ] := 1;
end;

You must also implement the OnImageIDRequest event, e.g.:

procedure TForm1.OnImageIDRequest(Sender: TObject; ID: integer; var Bitmap: TBitmap);
var
  io: TImageEnIO;
begin
  io := TImageEnIO.Create(self);
  io.AttachedBitmap := bmp; // bmp is a TBitmap object, defined at class level (must exists after the OnImageIDRequest exits)
  io.LoadFromFile( files[ID] );
  io.Free();
  Bitmap := bmp;
end;

4) If the images are frames of a media file (like AVI, MPEG, etc..) you can use LoadFromFileOnDemand:

ImageEnMView1.LoadFromFileOnDemand('video.mpeg');



How do I burn the layers (Lines, Ellipses, etc) added in TImageEnView into the image? (Save them as a JPEG file)

Lines, ellipses and other layers added to a TImageEnView can be merged to the background using the LayersMergeAll method, then save the image.



How do I modify the IPTC fields without loading the actual image?

The IPTC info is automatically loaded when you load the JPEG image using the LoadFromFile method. After this all IPTC information is loaded into the TImageEnView.IO.Params.IPTC_Info object. To read the caption you can write:

ImageEnView.IO.LoadFromFile('image.jpg');
Idx := ImageEnView.IO. Params.IPTC_Info.IndexOf(2, 120);
Caption := ImageEnView.IO.Params.IPTC_Info.StringItem[idx];

To modify the caption:

ImageEnView.IO.Params.IPTC_Info.StringItem[idx] := 'new caption';
ImageEnView.IO.SaveToFile('image2.jpg');

To modify IPTC info without loading the image use ParamsFromFile and InjectJpegIPTC methods, as follows:

ImageEnView.IO.ParamsFromFile('D:\Image.jpg');

...After modifying the IPTC info, save it

ImageEnView.IO.InjectJpegIPTC('D:\Image_ChangedMeta.jpg');


How I can save my JPEG without EXIF or other metadata?

Call ResetInfo. For example:

ImageEnView.IO.LoadFromFile('input.jpg');
ImageEnView.IO.Params.ResetInfo();
ImageEnView.IO.SaveToFile('output.jpg');


How can I check if the TImageEnView is empty (i.e. no bitmap is loaded)?

To empty the component use the "Blank" method. To check if it is empty use IsEmpty:

If ImageEnView1.IsEmpty() then
  ...


When a user selects a page of a multipage tiff image in a TImageEnMView, how can I display it in a TImageEnView?

1. To handle the display automatically specify your TImageEnView for AttachedImageEnView

ImageEnMView1.AttachedImageEnView := ImageEnView1;

2. To manually handle the image selection use the OnImageSelect event. To get the currently selected image simply use the Assign method:

procedure TForm1.ImageEnMView1ImageSelect(Sender: TObject; idx: Integer);
begin
  ImageEnView1.Assign( ImageEnMView1.IEBitmap );
end;


What is the correct way to load a Resource Image at runtime into an TImageEnView component in C++?

Here is an example:

TResourceStream *ResourceImage;
// Load from resource the About image ( a JPEG file).
ResourceImage = new TResourceStream((int)HInstance, "ABOUTBITMAP", RT_RCDATA);
MainForm->ImageAbout->IO->LoadFromStreamJpeg(ResourceImage);
delete ResourceImage;

Create a text file named "resource.rc" with the single line:
ABOUTBITMAP RCDATA "about.jpg"
Then add the Resource file to the project and compile.


How do I read custom TIFF tags?

This example shows how to read EXIF tags saved by Canon cameras:

var
  ms: TMemoryStream;
  tagReader1, tagReader2, tagReader3: TIETifTagsReader;
  i: integer;
  // some Canon tags
  m_nMacroMode, m_nLenghtTimer, m_Quality: integer;
  m_ImageType: string;
begin
  ImageEnView1.IO.LoadFromFile('Capture_00006.JPG');
  with ImageEnView1.IO.Params.JPEG_MarkerList do
  begin
    i := IndexOf( JPEG_APP1 );
    if i >= 0 then
    begin
      // there is EXIF info
      ms := TMemoryStream.Create;
      ms.Write( MarkerData[i][6], MarkerLength[i] );  // bypass first 4 bytes (must contain 'Exif')
      ms.Position := 0;

      tagReader1 := TIETifTagsReader.CreateFromStream( ms, 0 );             // read TIFF's IFD

      tagReader2 := TIETifTagsReader.CreateFromIFD( tagReader1, 34665 );    // read IFD in tag 34665 (SubEXIF)

      tagReader3 := TIETifTagsReader.CreateFromIFD( tagReader2, $927c );    // read IFD in tag $927C (MarkerData - Canon IFD data)

      // read Canon EXIF tags
      m_nMacroMode := tagReader3.GetIntegerIndexed(1, 1);
      m_nLenghtTimer := tagReader3.GetIntegerIndexed(1, 2);
      m_Quality := tagReader3.GetIntegerIndexed(1, 3);
      m_ImageType := tagReader3.GetString(6);

      tagReader3.Free();
      tagReader2.Free();
      tagReader1.Free();

      ms.Free();
    end;
  end;
end;


How do I compress my JPEGs to make them smaller?

Jpeg is a file format with variable compression rate. The property that regulates the compression (and the quality) is JPEG_Quality. So you should set this property before saving. For example:

ImageEnView.IO.LoadFromFile('input.jpg');
ImageEnView.IO.Params.JPEG_Quality := 70;
ImageEnView.IO.SaveToFile('output.jpg');

The default is 80, which provides a good balance between quality and file size.

To estimate the value used to create your file, use:
Quality := IECalcJpegFileQuality('input.jpg');

So you could write:

ImageEnView.IO.LoadFromFile('input.jpg');
ImageEnView.IO.Params.JPEG_Quality := IECalcJpegFileQuality('input.jpg');
ImageEnView.IO.SaveToFile('output.jpg');

If the file is still too large it may contain metatags (text info). To remove them, call ResetInfo before saving:

ImageEnView.IO.Params.ResetInfo();


How do I load embedded JPEG images in a Raw file?

Use the RAW_GetEmbeddedJpeg property:

// Load the embedded JPEG (loading a half size raw if there is no embedded JPEG)
ImageEnView.IO.Params.RAW_GetEmbeddedJpeg := True;
ImageEnView.IO.Params.RAW_HalfSize := True;


How do I always create a polygon when inserting a polyline layer?

Just set LayersAutoClosePolylines:

// Always close polylines
ImageEnView1.LayersAutoClosePolylines := iecmAlways;


How do I read Camera RAW formats?

To read Camera RAW files you must add ielib.dll to your EXE folder, or set IEGlobalSettings().CameraRawEngine to ieenWIC.


Why do I get "Floating point overflow" when printing?

This can happen on shared printers due to a bug in the VCL or printer drivers. Try disabling FPU exceptions by executing this before your printing code:

Set8087CW($133F);


Can I suppress ImageEn exceptions in the IDE, such as image loading errors?

Yes, you can add the ImageEn exception type, EIEException to Tools > Options, Debugger, Embarcadero Debuggers, Language Exceptions.

For more detail on common exceptions, see ImageEn Standard Exceptions