GdPicture.NET.14.API
GdPicture14 Namespace / GdPicturePDF Class / GetPageImageResolution Method
The 0-based index of the image within the current page. It must be a value from 0 to GdPicturePDF.GetPageImageCount-1.
Output parameter. The horizontal resolution (DPI) of the specified image.
Output parameter. The vertical resolution (DPI) of the specified image.
Example





In This Topic
GetPageImageResolution Method (GdPicturePDF)
In This Topic
Returns the vertical and the horizontal resolution (DPI) of an image, specified by its index within the currently selected page of the loaded PDF document.
Syntax
'Declaration
 
Public Function GetPageImageResolution( _
   ByVal ImageIdx As Integer, _
   ByRef HorizontalResolution As Single, _
   ByRef VerticalResolution As Single _
) As GdPictureStatus
public GdPictureStatus GetPageImageResolution( 
   int ImageIdx,
   ref float HorizontalResolution,
   ref float VerticalResolution
)
public function GetPageImageResolution( 
    ImageIdx: Integer;
   var  HorizontalResolution: Single;
   var  VerticalResolution: Single
): GdPictureStatus; 
public function GetPageImageResolution( 
   ImageIdx : int,
   HorizontalResolution : float,
   VerticalResolution : float
) : GdPictureStatus;
public: GdPictureStatus GetPageImageResolution( 
   int ImageIdx,
   ref float HorizontalResolution,
   ref float VerticalResolution
) 
public:
GdPictureStatus GetPageImageResolution( 
   int ImageIdx,
   float% HorizontalResolution,
   float% VerticalResolution
) 

Parameters

ImageIdx
The 0-based index of the image within the current page. It must be a value from 0 to GdPicturePDF.GetPageImageCount-1.
HorizontalResolution
Output parameter. The horizontal resolution (DPI) of the specified image.
VerticalResolution
Output parameter. The vertical resolution (DPI) of the specified image.

Return Value

A member of the GdPictureStatus enumeration. If the method has been successfully followed, then the return value is GdPictureStatus.OK.

We strongly recommend always checking this status first.

Remarks
This method is only allowed for use with non-encrypted documents.
Example
How to find out the resolution (both horizontal and vertical) of all images contained within the PDF document.
Dim caption As String = "Example: GetPageImageResolution"
Dim gdpicturePDF As New GdPicturePDF()
If gdpicturePDF.LoadFromFile("test.pdf", False) = GdPictureStatus.OK Then
    Dim message As String = ""
    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
                Dim imageCount As Integer = gdpicturePDF.GetPageImageCount()
                status = gdpicturePDF.GetStat()
                If (status = GdPictureStatus.OK) AndAlso (imageCount > 0) Then
                    Dim hRes As Single = 0, vRes As Single = 0
                    For j As Integer = 0 To imageCount - 1
                        status = gdpicturePDF.GetPageImageResolution(j, hRes, vRes)
                        If status = GdPictureStatus.OK Then
                            message = message + "The image indexed as " + j.ToString() + " has the following resolution: horizontal = " + hRes.ToString() + ", vertical = " + vRes.ToString() + "." + vbCrLf
                        Else
                            message = message + "The GetPageImageResolution() 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 with the status: " + status.ToString() + vbCrLf
                    End If
                End If
            Else
                message = message + "The SelectPage() method has failed for the page 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: GetPageImageResolution";
GdPicturePDF gdpicturePDF = new GdPicturePDF();
if (gdpicturePDF.LoadFromFile("test.pdf", false) == GdPictureStatus.OK)
{
    string message = "";
    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";
                int imageCount = gdpicturePDF.GetPageImageCount();
                status = gdpicturePDF.GetStat();
                if ((status == GdPictureStatus.OK) && (imageCount > 0))
                {
                    float hRes = 0, vRes = 0;
                    for (int j = 0; j < imageCount; j++)
                    {
                        status = gdpicturePDF.GetPageImageResolution(j, ref hRes, ref vRes);
                        if (status == GdPictureStatus.OK)
                            message = message + "The image indexed as " + j.ToString() + " has the following resolution: horizontal = " + hRes.ToString() + ", vertical = " + vRes.ToString() + ".\n";
                        else
                            message = message + "The GetPageImageResolution() 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 with the status: " + status.ToString() + "\n";
                }
            }
            else
            {
                message = message + "The SelectPage() method has failed for the page 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