How to Access & Extract Images from Presentation Shapes inside .NET Apps

This technical tip explains how .NET developers can extract images from presentation shapes inside their .NET applications.  Images are added in slide background and shapes. Sometimes, it is required to extract the images added in the presentation shapes. The images are added in IPPImageCollection inside Presentation Document Object Model (DOM). This article covers the feature of accessing the images in presentation shape, extracting them from presentation collection and saving them in a file. In Aspose.Slides for .NET, images can be added to slide shape and slide background. The images are added in IPPImageCollection of the presentation. In this example we will traverse through each shape inside every slide of presentation and see if there is any image added in slide shape. If the image will be found for any shape, we will extract that and will save it in file. The following code snippet will serve the purpose.

// Code Snippet for Extracting images from presentation shapes

[C# Code Sample]
 
String path = @"D:\Aspose Data\";
//Accessing the presentation
Presentation pres = new Presentation(path + "ExtractImages.pptx");
Aspose.Slides.IPPImage img = null;
Aspose.Slides.IPPImage Backimg = null;

int slideIndex = 0;
String ImageType = "";
bool ifImageFound = false;
for (int i = 0; i < pres.Slides.Count; i++)
{

    slideIndex++;
    //Accessing the first slide
    ISlide sl = pres.Slides[i];
    System.Drawing.Imaging.ImageFormat Format = System.Drawing.Imaging.ImageFormat.Jpeg;

    //Accessing the first slide Slide sl = pres.getSlideByPosition(i);
    if (sl.Background.FillFormat.FillType == FillType.Picture)
    {
        //Getting the back picture  
        Backimg = sl.Background.FillFormat.PictureFillFormat.Picture.Image;

        //Setting the desired picture format 

        ImageType = Backimg.ContentType;
        ImageType = ImageType.Remove(0, ImageType.IndexOf("/") + 1);
        Format = GetImageFormat(ImageType);

        String ImagePath = path + "BackImage_";
        Backimg.SystemImage.Save(ImagePath + "Slide_" + slideIndex.ToString() + "." + ImageType, Format);

    }
    else
    {
        if (sl.LayoutSlide.Background.FillFormat.FillType == FillType.Picture)
        {
            //Getting the back picture  
            Backimg = sl.LayoutSlide.Background.FillFormat.PictureFillFormat.Picture.Image;

            //Setting the desired picture format 

            ImageType = Backimg.ContentType;
            ImageType = ImageType.Remove(0, ImageType.IndexOf("/") + 1);
            Format = GetImageFormat(ImageType);

            String ImagePath = path + "BackImage_Slide_" + i;
            Backimg.SystemImage.Save(ImagePath + "LayoutSlide_" + slideIndex.ToString() + "." + ImageType, Format);

        }
    }

    for (int j = 0; j < sl.Shapes.Count; j++)
    {
        // Accessing the shape with picture
        IShape sh = sl.Shapes[j];

        if (sh is AutoShape)
        {
            AutoShape ashp = (AutoShape)sh;
            if (ashp.FillFormat.FillType == FillType.Picture)
            {
                img = ashp.FillFormat.PictureFillFormat.Picture.Image;
                ImageType = img.ContentType;
                ImageType = ImageType.Remove(0, ImageType.IndexOf("/") + 1);
                ifImageFound = true;

            }
        }

        else if (sh is PictureFrame)
        {
            IPictureFrame pf = (IPictureFrame)sh;
            if (pf.FillFormat.FillType == FillType.Picture)
            {
                img = pf.PictureFormat.Picture.Image;
                ImageType = img.ContentType;
                ImageType = ImageType.Remove(0, ImageType.IndexOf("/") + 1);
                ifImageFound = true;
            }
        }


        //
        //Setting the desired picture format
        if (ifImageFound)
        {
            Format = GetImageFormat(ImageType);
            String ImagePath = path + "Slides\\Image_";
            img.SystemImage.Save(ImagePath + "Slide_" + slideIndex.ToString() + "_Shape_" + j.ToString() + "." + ImageType, Format);
        }
        ifImageFound = false;
    }
}



public static System.Drawing.Imaging.ImageFormat GetImageFormat(String ImageType)
{
    System.Drawing.Imaging.ImageFormat Format = System.Drawing.Imaging.ImageFormat.Jpeg;
    switch (ImageType)
    {
        case "jpeg":
            Format = System.Drawing.Imaging.ImageFormat.Jpeg;
            break;

        case "emf":
            Format = System.Drawing.Imaging.ImageFormat.Emf;
            break;

        case "bmp":
            Format = System.Drawing.Imaging.ImageFormat.Bmp;
            break;

        case "png":
            Format = System.Drawing.Imaging.ImageFormat.Png;
            break;

        case "wmf":
            Format = System.Drawing.Imaging.ImageFormat.Wmf;
            break;

        case "gif":
            Format = System.Drawing.Imaging.ImageFormat.Gif;
            break;

    }
    return Format;


}
 
[VB.NET Code Sample]
 

Dim path As String = "D:\Aspose Data\"
'Accessing the presentation
Dim pres As New Presentation(path & "ExtractImages.pptx")
Dim img As Aspose.Slides.IPPImage = Nothing
Dim Backimg As Aspose.Slides.IPPImage = Nothing

Dim slideIndex As Integer = 0
Dim ImageType As String = ""
Dim ifImageFound As Boolean = False
For i As Integer = 0 To pres.Slides.Count - 1

	slideIndex += 1
	'Accessing the first slide
	Dim sl As ISlide = pres.Slides(i)
	Dim Format As System.Drawing.Imaging.ImageFormat = System.Drawing.Imaging.ImageFormat.Jpeg

	'Accessing the first slide Slide sl = pres.getSlideByPosition(i);
	If sl.Background.FillFormat.FillType = FillType.Picture Then
		'Getting the back picture  
		Backimg = sl.Background.FillFormat.PictureFillFormat.Picture.Image

		'Setting the desired picture format 

		ImageType = Backimg.ContentType
		ImageType = ImageType.Remove(0, ImageType.IndexOf("/") + 1)
		Format = GetImageFormat(ImageType)

		Dim ImagePath As String = path & "BackImage_"
		Backimg.SystemImage.Save(ImagePath & "Slide_" & slideIndex.ToString() & "." & ImageType, Format)

	Else
		If sl.LayoutSlide.Background.FillFormat.FillType = FillType.Picture Then
'Getting the back picture  
Backimg = sl.LayoutSlide.Background.FillFormat.PictureFillFormat.Picture.Image

'Setting the desired picture format 

ImageType = Backimg.ContentType
ImageType = ImageType.Remove(0, ImageType.IndexOf("/") + 1)
Format = GetImageFormat(ImageType)

Dim ImagePath As String = path & "BackImage_Slide_" & i
Backimg.SystemImage.Save(ImagePath & "LayoutSlide_" & slideIndex.ToString() & "." & ImageType, Format)

		End If
	End If

	For j As Integer = 0 To sl.Shapes.Count - 1
		' Accessing the shape with picture
		Dim sh As IShape = sl.Shapes(j)

		If TypeOf sh Is AutoShape Then
Dim ashp As AutoShape = CType(sh, AutoShape)
If ashp.FillFormat.FillType = FillType.Picture Then
	img = ashp.FillFormat.PictureFillFormat.Picture.Image
	ImageType = img.ContentType
	ImageType = ImageType.Remove(0, ImageType.IndexOf("/") + 1)
	ifImageFound = True

End If

		ElseIf TypeOf sh Is PictureFrame Then
Dim pf As IPictureFrame = CType(sh, IPictureFrame)
If pf.FillFormat.FillType = FillType.Picture Then
	img = pf.PictureFormat.Picture.Image
	ImageType = img.ContentType
	ImageType = ImageType.Remove(0, ImageType.IndexOf("/") + 1)
	ifImageFound = True
End If
		End If


		'
		'Setting the desired picture format
		If ifImageFound Then
Format = GetImageFormat(ImageType)
Dim ImagePath As String = path & "Slides\Image_"
img.SystemImage.Save(ImagePath & "Slide_" & slideIndex.ToString() & "_Shape_" & j.ToString() & "." & ImageType, Format)
		End If
		ifImageFound = False
	Next j
Next i
		End Sub



Public Shared Function GetImageFormat(ByVal ImageType As String) As System.Drawing.Imaging.ImageFormat

	Dim Format As System.Drawing.Imaging.ImageFormat = System.Drawing.Imaging.ImageFormat.Jpeg

	Select Case ImageType
		Case "jpeg"
			Format = System.Drawing.Imaging.ImageFormat.Jpeg

		Case "emf"
			Format = System.Drawing.Imaging.ImageFormat.Emf

		Case "bmp"
		Format = System.Drawing.Imaging.ImageFormat.Bmp

		Case "png"
			Format = System.Drawing.Imaging.ImageFormat.Png

		Case "wmf"
			Format = System.Drawing.Imaging.ImageFormat.Wmf

		Case "gif"
			Format = System.Drawing.Imaging.ImageFormat.Gif

	End Select

	Return Format

End Function