Converting Images to PDF Documents with PDFium VCL in Delphi

Converting images to PDF is a common requirement for document management, archiving, and sharing. The Image to PDF demo shows how to create multi-page PDF documents from a collection of images using PDFium VCL.

Overview

This demo allows users to select multiple images, preview them, reorder if needed, and convert them into a single PDF document. Each image becomes a page in the PDF, properly scaled and centered.

Key Features

Multiple Image Support – Add multiple images at once
Format Support – JPEG, PNG, BMP, GIF, and TIFF images
Image Preview – Preview images before conversion
Automatic Page Sizing – Portrait or landscape based on image orientation
Smart Scaling – Images are scaled to fit the page with margins
Image Information – Original size and scale factor displayed on each page

PDFium DLL Requirements

Before running any PDFium VCL application, ensure the PDFium DLL files are installed:

pdfium32.dll / pdfium64.dll – Standard versions (~5-6 MB)
pdfium32v8.dll / pdfium64v8.dll – With V8 JavaScript engine (~23-27 MB)

Installation: Run PDFiumVCL\DLLs\CopyDlls.bat as Administrator to automatically copy the DLLs to Windows system directories.

Creating PDFs from Images

The core conversion process:

procedure TFormMain.CreatePDFFromImages;
var
  I: Integer;
  PageWidth, PageHeight: Double;
  ImageWidth, ImageHeight: Double;
  ScaleX, ScaleY, Scale: Double;
  ImageSize: TSize;
  X, Y: Double;
  Picture: TPicture;
begin
  if FImageList.Count = 0 then
    Exit;
    
  ProgressBar.Visible := True;
  ProgressBar.Max := FImageList.Count;
  ProgressBar.Position := 0;
  
  try
    // Create new PDF document
    Pdf.CreateDocument;
    Pdf.Active := True;
    
    for I := 0 to FImageList.Count - 1 do
    begin
      try
        // Load the image
        Picture := TPicture.Create;
        try
          Picture.LoadFromFile(FImageList[I]);
          
          // Get image dimensions
          ImageSize.cx := Picture.Width;
          ImageSize.cy := Picture.Height;
          
          // Set page orientation based on image
          if ImageSize.cx &gt; ImageSize.cy then
          begin
            // Landscape
            PageWidth := 842;  // A4 landscape
            PageHeight := 595;
          end
          else
          begin
            // Portrait
            PageWidth := 595;  // A4 portrait
            PageHeight := 842;
          end;
          
          // Create page
          Pdf.AddPage(I + 1, PageWidth, PageHeight);
          Pdf.PageNumber := I + 1;
          
          // Calculate scaling
          ImageWidth := ImageSize.cx;
          ImageHeight := ImageSize.cy;
          
          ScaleX := (PageWidth - 80) / ImageWidth;   // 40pt margin each side
          ScaleY := (PageHeight - 120) / ImageHeight; // 40pt + space for text
          Scale := Min(ScaleX, ScaleY);
          
          ImageWidth := ImageWidth * Scale;
          ImageHeight := ImageHeight * Scale;
          
          // Center on page
          X := (PageWidth - ImageWidth) / 2;
          Y := (PageHeight - ImageHeight) / 2;
          
          // Add image to PDF
          Pdf.AddPicture(Picture, X, Y, ImageWidth, ImageHeight);
          
          // Add image information
          Pdf.AddText(Format('File: %s', [ExtractFileName(FImageList[I])]),
            'Arial', 10, X, Y + ImageHeight + 10, clBlack, $FF, 0.0);
          Pdf.AddText(Format('Original: %dx%d px, Scale: %.1f%%',
            [ImageSize.cx, ImageSize.cy, Scale * 100]),
            'Arial', 8, X, Y + ImageHeight + 25, clGray, $FF, 0.0);
            
        finally
          Picture.Free;
        end;
        
        ProgressBar.Position := I + 1;
        Application.ProcessMessages;
        
      except
        on E: Exception do
          // Continue with next image on error
          LabelStatus.Caption := 'Error: ' + E.Message;
      end;
    end;
    
    // Save the PDF
    Pdf.SaveAs(SaveDialog.FileName);
    ShowMessage(Format('PDF created with %d pages!', [FImageList.Count]));
    
  finally
    ProgressBar.Visible := False;
    Pdf.Active := False;
  end;
end;

100

procedure TFormMain.CreatePDFFromImages;

var

I: Integer;

PageWidth, PageHeight: Double;

ImageWidth, ImageHeight: Double;

ScaleX, ScaleY, Scale: Double;

ImageSize: TSize;

X, Y: Double;

Picture: TPicture;

begin

if FImageList.Count = 0 then

Exit;

ProgressBar.Visible := True;

ProgressBar.Max := FImageList.Count;

ProgressBar.Position := 0;

try

// Create new PDF document

Pdf.CreateDocument;

Pdf.Active := True;

for I := 0 to FImageList.Count - 1 do

begin

try

// Load the image

Picture := TPicture.Create;

try

Picture.LoadFromFile(FImageList[I]);

// Get image dimensions

ImageSize.cx := Picture.Width;

ImageSize.cy := Picture.Height;

// Set page orientation based on image

if ImageSize.cx > ImageSize.cy then

begin

// Landscape

PageWidth := 842; // A4 landscape

PageHeight := 595;

end

else

begin

// Portrait

PageWidth := 595; // A4 portrait

PageHeight := 842;

end;

// Create page

Pdf.AddPage(I + 1, PageWidth, PageHeight);

Pdf.PageNumber := I + 1;

// Calculate scaling

ImageWidth := ImageSize.cx;

ImageHeight := ImageSize.cy;

ScaleX := (PageWidth - 80) / ImageWidth; // 40pt margin each side

ScaleY := (PageHeight - 120) / ImageHeight; // 40pt + space for text

Scale := Min(ScaleX, ScaleY);

ImageWidth := ImageWidth * Scale;

ImageHeight := ImageHeight * Scale;

// Center on page

X := (PageWidth - ImageWidth) / 2;

Y := (PageHeight - ImageHeight) / 2;

// Add image to PDF

Pdf.AddPicture(Picture, X, Y, ImageWidth, ImageHeight);

// Add image information

Pdf.AddText(Format('File: %s', [ExtractFileName(FImageList[I])]),

'Arial', 10, X, Y + ImageHeight + 10, clBlack, $FF, 0.0);

Pdf.AddText(Format('Original: %dx%d px, Scale: %.1f%%',

[ImageSize.cx, ImageSize.cy, Scale * 100]),

'Arial', 8, X, Y + ImageHeight + 25, clGray, $FF, 0.0);

finally

Picture.Free;

end;

ProgressBar.Position := I + 1;

Application.ProcessMessages;

except

on E: Exception do

// Continue with next image on error

LabelStatus.Caption := 'Error: ' + E.Message;

end;

// Save the PDF

Pdf.SaveAs(SaveDialog.FileName);

ShowMessage(Format('PDF created with %d pages!', [FImageList.Count]));

finally

ProgressBar.Visible := False;

Pdf.Active := False;

end;

Adding Images to the List

procedure TFormMain.BtnAddImagesClick(Sender: TObject);
var
  I: Integer;
  ListItem: TListItem;
  FileSize: Int64;
  FileSizeStr: string;
begin
  if OpenPictureDialog.Execute then
  begin
    for I := 0 to OpenPictureDialog.Files.Count - 1 do
    begin
      FImageList.Add(OpenPictureDialog.Files[I]);
      
      // Add to ListView
      ListItem := ListView.Items.Add;
      ListItem.Caption := ExtractFileName(OpenPictureDialog.Files[I]);
      ListItem.SubItems.Add(OpenPictureDialog.Files[I]); // Full path
      
      // Get file size
      try
        FileSize := GetFileSizeHelper(OpenPictureDialog.Files[I]);
        if FileSize &gt;= 1024 * 1024 then
          FileSizeStr := Format('%.1f MB', [FileSize / (1024 * 1024)])
        else if FileSize &gt;= 1024 then
          FileSizeStr := Format('%.1f KB', [FileSize / 1024])
        else
          FileSizeStr := Format('%d bytes', [FileSize]);
      except
        FileSizeStr := 'Unknown';
      end;
      ListItem.SubItems.Add(FileSizeStr);
    end;
    
    UpdateUI;
    LabelStatus.Caption := Format('Added %d image(s). Total: %d images',
      [OpenPictureDialog.Files.Count, FImageList.Count]);
  end;
end;

procedure TFormMain.BtnAddImagesClick(Sender: TObject);

var

I: Integer;

ListItem: TListItem;

FileSize: Int64;

FileSizeStr: string;

begin

if OpenPictureDialog.Execute then

begin

for I := 0 to OpenPictureDialog.Files.Count - 1 do

begin

FImageList.Add(OpenPictureDialog.Files[I]);

// Add to ListView

ListItem := ListView.Items.Add;

ListItem.Caption := ExtractFileName(OpenPictureDialog.Files[I]);

ListItem.SubItems.Add(OpenPictureDialog.Files[I]); // Full path

// Get file size

try

FileSize := GetFileSizeHelper(OpenPictureDialog.Files[I]);

if FileSize >= 1024 * 1024 then

FileSizeStr := Format('%.1f MB', [FileSize / (1024 * 1024)])

else if FileSize >= 1024 then

FileSizeStr := Format('%.1f KB', [FileSize / 1024])

else

FileSizeStr := Format('%d bytes', [FileSize]);

except

FileSizeStr := 'Unknown';

end;

ListItem.SubItems.Add(FileSizeStr);

end;

UpdateUI;

LabelStatus.Caption := Format('Added %d image(s). Total: %d images',

[OpenPictureDialog.Files.Count, FImageList.Count]);

end;

Using AddPicture Method

The AddPicture method accepts a TPicture object, which supports various image formats:

// Add picture with automatic sizing
procedure TPdf.AddPicture(Picture: TPicture; X, Y: Double);

// Add picture with specific size
procedure TPdf.AddPicture(Picture: TPicture; X, Y, Width, Height: Double);

// Add picture with automatic sizing

procedure TPdf.AddPicture(Picture: TPicture; X, Y: Double);

// Add picture with specific size

procedure TPdf.AddPicture(Picture: TPicture; X, Y, Width, Height: Double);

Adding JPEG Images Directly

For JPEG images, you can use the optimized AddJpegImage method:

function AddJpegFromFile(const FileName: string): Boolean;
var
  Pdf: TPdf;
  FileStream: TFileStream;
begin
  Pdf := TPdf.Create(nil);
  try
    Pdf.CreateDocument;
    Pdf.Active := True;
    Pdf.AddPage(1, 595, 842);
    Pdf.PageNumber := 1;
    
    FileStream := TFileStream.Create(FileName, fmOpenRead);
    try
      // Add JPEG directly - more efficient than loading as TPicture
      Result := Pdf.AddJpegImage(FileStream, 50, 50, 495, 742);
    finally
      FileStream.Free;
    end;
    
    Pdf.SaveAs('output.pdf');
    
  finally
    Pdf.Active := False;
    Pdf.Free;
  end;
end;

function AddJpegFromFile(const FileName: string): Boolean;

var

Pdf: TPdf;

FileStream: TFileStream;

begin

Pdf := TPdf.Create(nil);

try

Pdf.CreateDocument;

Pdf.Active := True;

Pdf.AddPage(1, 595, 842);

Pdf.PageNumber := 1;

FileStream := TFileStream.Create(FileName, fmOpenRead);

try

// Add JPEG directly - more efficient than loading as TPicture

Result := Pdf.AddJpegImage(FileStream, 50, 50, 495, 742);

finally

FileStream.Free;

end;

Pdf.SaveAs('output.pdf');

finally

Pdf.Active := False;

Pdf.Free;

end;

Previewing Selected Images

procedure TFormMain.ListViewSelectItem(Sender: TObject; Item: TListItem;
  Selected: Boolean);
begin
  if Selected and (Item &lt;&gt; nil) then
  begin
    LoadImagePreview(Item.SubItems[0]); // Full path
  end;
end;

procedure TFormMain.LoadImagePreview(const FileName: string);
begin
  try
    if FileExists(FileName) then
    begin
      ImagePreview.Picture.LoadFromFile(FileName);
      ImagePreview.Proportional := True;
      ImagePreview.Stretch := True;
      LabelStatus.Caption := 'Preview: ' + ExtractFileName(FileName);
    end;
  except
    on E: Exception do
    begin
      ImagePreview.Picture.Assign(nil);
      LabelStatus.Caption := 'Error loading preview: ' + E.Message;
    end;
  end;
end;

procedure TFormMain.ListViewSelectItem(Sender: TObject; Item: TListItem;

Selected: Boolean);

begin

if Selected and (Item <> nil) then

begin

LoadImagePreview(Item.SubItems[0]); // Full path

end;

procedure TFormMain.LoadImagePreview(const FileName: string);

begin

try

if FileExists(FileName) then

begin

ImagePreview.Picture.LoadFromFile(FileName);

ImagePreview.Proportional := True;

ImagePreview.Stretch := True;

LabelStatus.Caption := 'Preview: ' + ExtractFileName(FileName);

end;

except

on E: Exception do

begin

ImagePreview.Picture.Assign(nil);

LabelStatus.Caption := 'Error loading preview: ' + E.Message;

end;

Removing and Reordering Images

procedure TFormMain.BtnRemoveSelectedClick(Sender: TObject);
var
  I, RemovedCount: Integer;
begin
  RemovedCount := 0;
  
  if ListView.SelCount &gt; 0 then
  begin
    // Remove from back to front to avoid index issues
    for I := ListView.Items.Count - 1 downto 0 do
    begin
      if ListView.Items[I].Selected then
      begin
        FImageList.Delete(I);
        ListView.Items.Delete(I);
        Inc(RemovedCount);
      end;
    end;
    
    if (FImageList.Count = 0) or (ListView.Selected = nil) then
      ImagePreview.Picture.Assign(nil);
      
    UpdateUI;
    LabelStatus.Caption := Format('Removed %d item(s). Total: %d images',
      [RemovedCount, FImageList.Count]);
  end;
end;

procedure TFormMain.BtnRemoveSelectedClick(Sender: TObject);

var

I, RemovedCount: Integer;

begin

RemovedCount := 0;

if ListView.SelCount > 0 then

begin

// Remove from back to front to avoid index issues

for I := ListView.Items.Count - 1 downto 0 do

begin

if ListView.Items[I].Selected then

begin

FImageList.Delete(I);

ListView.Items.Delete(I);

Inc(RemovedCount);

end;

if (FImageList.Count = 0) or (ListView.Selected = nil) then

ImagePreview.Picture.Assign(nil);

UpdateUI;

LabelStatus.Caption := Format('Removed %d item(s). Total: %d images',

[RemovedCount, FImageList.Count]);

end;

Setting Up the Dialog

procedure TFormMain.FormCreate(Sender: TObject);
begin
  FImageList := TStringList.Create;
  
  // Setup ListView
  ListView.ViewStyle := vsReport;
  ListView.Columns.Add.Caption := 'File Name';
  ListView.Columns.Add.Caption := 'Path';
  ListView.Columns.Add.Caption := 'Size';
  ListView.Columns[0].Width := 200;
  ListView.Columns[1].Width := 300;
  ListView.Columns[2].Width := 100;
  ListView.RowSelect := True;
  ListView.MultiSelect := True;
  
  // Setup dialogs
  OpenPictureDialog.Filter := 
    'Image Files|*.jpg;*.jpeg;*.png;*.bmp;*.gif;*.tiff;*.tif|' +
    'JPEG Files|*.jpg;*.jpeg|' +
    'PNG Files|*.png|' +
    'Bitmap Files|*.bmp|' +
    'All Files|*.*';
  OpenPictureDialog.Options := [ofAllowMultiSelect, ofPathMustExist, ofFileMustExist];
  
  SaveDialog.Filter := 'PDF Files|*.pdf|All Files|*.*';
  SaveDialog.DefaultExt := 'pdf';
  
  UpdateUI;
end;

procedure TFormMain.FormCreate(Sender: TObject);

begin

FImageList := TStringList.Create;

// Setup ListView

ListView.ViewStyle := vsReport;

ListView.Columns.Add.Caption := 'File Name';

ListView.Columns.Add.Caption := 'Path';

ListView.Columns.Add.Caption := 'Size';

ListView.Columns[0].Width := 200;

ListView.Columns[1].Width := 300;

ListView.Columns[2].Width := 100;

ListView.RowSelect := True;

ListView.MultiSelect := True;

// Setup dialogs

OpenPictureDialog.Filter :=

'Image Files|*.jpg;*.jpeg;*.png;*.bmp;*.gif;*.tiff;*.tif|' +

'JPEG Files|*.jpg;*.jpeg|' +

'PNG Files|*.png|' +

'Bitmap Files|*.bmp|' +

'All Files|*.*';

OpenPictureDialog.Options := [ofAllowMultiSelect, ofPathMustExist, ofFileMustExist];

SaveDialog.Filter := 'PDF Files|*.pdf|All Files|*.*';

SaveDialog.DefaultExt := 'pdf';

UpdateUI;

end;

Use Cases

Photo Albums – Create PDF albums from digital photos
Document Scanning – Combine scanned page images into a single PDF
Portfolio Creation – Build portfolio PDFs from artwork images
Archiving – Convert image collections to PDFs for long-term storage
Report Generation – Include screenshots and diagrams in PDF reports

Conclusion

The Image to PDF demo shows how PDFium VCL makes it easy to create professional PDF documents from images. With automatic page sizing, smart scaling, and support for multiple image formats, you can build powerful image-to-PDF conversion tools.

The AddPicture method handles the complexity of embedding images into PDF pages, while you focus on the user interface and workflow of your application.

Try PDFium VCL Component from loslab.com and start creating PDFs from images today.