'''' This code is part of Document Solutions for PDF .NET demos.'' Copyright (c) MESCIUS inc. All rights reserved.''Imports System.IOImports System.DrawingImports System.Collections.GenericImports GrapeCity.Documents.PdfImports GrapeCity.Documents.Pdf.Graphics.ImagesImports GrapeCity.Documents.Pdf.SpecImports GrapeCity.Documents.Text
Public Class GetImageProperties    Public Function CreatePDF(ByVal stream As Stream) As Integer        Using fs = File.OpenRead(Path.Combine("Resources", "PDFs", "Wetlands.pdf"))            Dim docSrc = New GcPdfDocument()            docSrc.Load(fs)
            ' Get the images in the loaded PDF and print their info into the resulting PDF:            Dim imageInfos = docSrc.GetImages()
            ' The PDF to hold the results:            Dim doc = New GcPdfDocument()            Dim page = doc.NewPage()            ' Set up a TextLayout to format the results:            Dim tl = page.Graphics.CreateTextLayout()            tl.DefaultFormat.Font = StandardFonts.Courier            tl.DefaultFormat.FontSize = 14            tl.MaxWidth = doc.PageSize.Width            tl.MaxHeight = doc.PageSize.Height            tl.MarginAll = tl.Resolution            Dim captionFmt = New TextFormat(tl.DefaultFormat) With {.Font = StandardFonts.CourierBold, .FontSize = tl.DefaultFormat.FontSize + 2}
            Dim i As Integer = 0            For Each imageInfo In imageInfos                i += 1                tl.AppendLine($"Image {i}", captionFmt)
                ' PdfImageBase class represents an image in the loaded PDF file:                Dim img As PdfImageBase = imageInfo.Image
                tl.AppendLine($"PdfImage object ID: {img.ObjID}")                ' PdfImageBase is derived from PdfDictWrapper type, it has methods                ' that allow you to access properties/data of the underlying PDF stream object:                Using psi As PdfStreamInfo = img.GetPdfStreamInfo()                    tl.AppendLine($"    Image stream length: {psi.Stream.Length}")                    tl.AppendLine($"        ImageFilterName: {psi.ImageFilterName}")                    tl.AppendLine($"ImageFilterDecodeParams: {psi.ImageFilterDecodeParams}")                    ' Dump the content of the ImageFilterDecodeParams if it exists:                    If psi.ImageFilterDecodeParams IsNot Nothing Then                        For Each kvp In psi.ImageFilterDecodeParams.Dict                            tl.AppendLine($"{kvp.Key}: {kvp.Value}")                        Next                        ' An example of how to get the value of BlackIs1:                        Dim blackIs1 = psi.ImageFilterDecodeParams.GetBool(PdfName.Std.BlackIs1, Nothing)                        tl.AppendLine($"BlackIs1: {blackIs1}")                    End If                End Using                ' Dump the properties of PdfImage dictionary:                tl.AppendLine()                tl.AppendLine("Properties of PdfImage dictionary:")                For Each kvp As KeyValuePair(Of PdfName, IPdfObject) In img.PdfDict.Dict                    tl.AppendLine($"{kvp.Key}: {kvp.Value}")                Next                '                Dim cs = img.Get(Of IPdfObject)(PdfName.Std.ColorSpace)                tl.AppendLine($"ColorSpace: {cs.GetType().Name} {cs}")                Dim bpc = img.Get(Of IPdfObject)(PdfName.Std.BitsPerComponent)                tl.AppendLine($"BitsPerComponent: {bpc?.GetType().Name} {bpc}")                tl.AppendLine()            Next
            ' Render the results:            tl.PerformLayout(True)            Do                Dim rest As TextLayout = Nothing                Dim splitResult = tl.Split(Nothing, rest)                page.Graphics.DrawTextLayout(tl, PointF.Empty)                If splitResult <> SplitResult.Split Then                    Exit Do                End If                tl = rest                tl.MarginTop = tl.Resolution                page = doc.Pages.Add()            Loop
            ' Append the source PDF to the result for reference:            doc.MergeWithDocument(docSrc)
            '' Done:            doc.Save(stream)            Return doc.Pages.Count        End Using    End FunctionEnd Class