The 0-based index of the image within the current page. It must be a value from 0 to GdPicturePDF.GetPageImageCount-1.
Example





In This Topic
GdPicture14 Namespace / GdPicturePDF Class / GetPageImageFilters Method

GetPageImageFilters Method (GdPicturePDF)

In This Topic
Returns the filters used to encode an image, specified by its index within the currently selected page of the loaded PDF document.
Syntax
'Declaration

 

Public Function GetPageImageFilters( _

   ByVal ImageIdx As Integer _

) As String()
public string[] GetPageImageFilters( 

   int ImageIdx

)
public function GetPageImageFilters( 

    ImageIdx: Integer

): array of String; 
public function GetPageImageFilters( 

   ImageIdx : int

) : String[];
public: string*[]* GetPageImageFilters( 

   int ImageIdx

) 
public:

array<String^>^ GetPageImageFilters( 

   int ImageIdx

) 

Parameters

ImageIdx
The 0-based index of the image within the current page. It must be a value from 0 to GdPicturePDF.GetPageImageCount-1.

Return Value

An array of strings including the names of the filters used to encode the specified image.

The GdPicturePDF.GetStat method can be subsequently used to determine if this method has been successful.

Remarks
This method is only allowed for use with non-encrypted documents.

It is recommend to use the GdPicturePDF.GetStat method to identify the specific reason for the method's failure, if any.

Just to inform you that the supported filters are: ASCIIHexDecode, ASCII85Decode, LZWDecode, FlateDecode, RunLengthDecode, CCITTFaxDecode, JBIG2Decode, DCTDecode, JPXDecode, Crypt. For further assistance, please refer to the PDF Reference, Section "Filters".

Example
How to find out used filters of all images contained within the PDF document.
Dim caption As String = "Example: GetPageImageFilters"

Dim gdpicturePDF As New GdPicturePDF()

If gdpicturePDF.LoadFromFile("test.pdf", False) = GdPictureStatus.OK Then

    Dim message As String = ""

    Dim filters As String() = Nothing

    Dim imageCount As Integer = 0

    Dim pageCount As Integer = gdpicturePDF.GetPageCount()

    Dim status As GdPictureStatus = gdpicturePDF.GetStat()

    If (status = GdPictureStatus.OK) AndAlso (pageCount > 0) Then

        For i As Integer = 1 To pageCount

            If gdpicturePDF.SelectPage(i) = GdPictureStatus.OK Then

                message = message + "Page nr." + i.ToString() + ":" + vbCrLf

                imageCount = gdpicturePDF.GetPageImageCount()

                status = gdpicturePDF.GetStat()

                If (status = GdPictureStatus.OK) AndAlso (imageCount > 0) Then

                    For j As Integer = 0 To imageCount - 1

                        filters = gdpicturePDF.GetPageImageFilters(j)

                        status = gdpicturePDF.GetStat()

                        If status = GdPictureStatus.OK Then

                            message = message + "The image indexed as " + j.ToString() + " has the following filters: " + String.Join(",", filters) + "." + vbCrLf

                        Else

                            message = message + "The GetPageImageFilters() method has failed for the image nr. " + j.ToString() + " with the status: " + status.ToString() + vbCrLf

                        End If

                    Next

                Else

                    If status = GdPictureStatus.OK Then

                        message = message + "This page doesn't contain any image." + vbCrLf

                    Else

                        message = message + "The GetPageImageCount() method has failed for the page nr. " + i.ToString() + " with the status: " + status.ToString() + vbCrLf

                    End If

                End If

            Else

                message = message + "The SelectPage() method has failed for the image nr. " + i.ToString() + " with the status: " + gdpicturePDF.GetStat().ToString() + vbCrLf

            End If

        Next

        MessageBox.Show(message, caption)

    Else

        If status = GdPictureStatus.OK Then

            MessageBox.Show("This file doesn't contain any page.", caption)

        Else

            MessageBox.Show("The GetPageCount() method has failed with the status: " + status.ToString(), caption)

        End If

    End If

Else

    MessageBox.Show("The file can't be loaded.", caption)

End If

gdpicturePDF.Dispose()
string caption = "Example: GetPageImageFilters";

GdPicturePDF gdpicturePDF = new GdPicturePDF();

if (gdpicturePDF.LoadFromFile("test.pdf", false) == GdPictureStatus.OK)

{

    string message = "";

    string[] filters = null;

    int imageCount = 0;

    int pageCount = gdpicturePDF.GetPageCount();

    GdPictureStatus status = gdpicturePDF.GetStat();

    if ((status == GdPictureStatus.OK) && (pageCount > 0))

    {

        for (int i = 1; i <= pageCount; i++)

        {

            if (gdpicturePDF.SelectPage(i) == GdPictureStatus.OK)

            {

                message = message + "Page nr." + i.ToString() + ":\n";

                imageCount = gdpicturePDF.GetPageImageCount();

                status = gdpicturePDF.GetStat();

                if ((status == GdPictureStatus.OK) && (imageCount > 0))

                {

                    for (int j = 0; j < imageCount; j++)

                    {

                        filters = gdpicturePDF.GetPageImageFilters(j);

                        status = gdpicturePDF.GetStat();

                        if (status == GdPictureStatus.OK)

                            message = message + "The image indexed as " + j.ToString() + " has the following filters: " + string.Join(",", filters) + "\n";

                        else

                            message = message + "The GetPageImageFilters() method has failed for the image nr. " + j.ToString() + " with the status: " + status.ToString() + "\n";

                    }

                }

                else

                {

                    if (status == GdPictureStatus.OK)

                        message = message + "This page doesn't contain any image.\n";

                    else

                        message = message + "The GetPageImageCount() method has failed for the page nr. " + i.ToString() + " with the status: " + status.ToString() + "\n";

                }

            }

            else

            {

                message = message + "The SelectPage() method has failed for the image nr. " + i.ToString() + " with the status: " + gdpicturePDF.GetStat().ToString() + "\n";

            }

        }

        MessageBox.Show(message, caption);

    }

    else

    {

        if (status == GdPictureStatus.OK)

            MessageBox.Show("This file doesn't contain any page.", caption);

        else

            MessageBox.Show("The GetPageCount() method has failed with the status: " + status.ToString(), caption);

    }

}

else

    MessageBox.Show("The file can't be loaded.", caption);

gdpicturePDF.Dispose();
See Also