PDF to image API in VB.NET with PDF.co Web API

PDF.co Web API: the Web API with a set of tools for documents manipulation, data conversion, data extraction, splitting and merging of documents. Includes image recognition, built-in OCR, barcode generation and barcode decoders to decode bar codes from scans, pictures and pdf.

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ByteScoutWebApiExample.sln

      
Microsoft Visual Studio Solution File, Format Version 12.00 # Visual Studio 15 VisualStudioVersion = 15.0.26730.10 MinimumVisualStudioVersion = 10.0.40219.1 Project("{F184B08F-C81C-45F6-A57F-5ABD9991F28F}") = "ByteScoutWebApiExample", "ByteScoutWebApiExample.vbproj", "{9B91124C-66C3-4BD9-B29E-168C1ABB15AC}" EndProject Global GlobalSection(SolutionConfigurationPlatforms) = preSolution Debug|Any CPU = Debug|Any CPU Release|Any CPU = Release|Any CPU EndGlobalSection GlobalSection(ProjectConfigurationPlatforms) = postSolution {9B91124C-66C3-4BD9-B29E-168C1ABB15AC}.Debug|Any CPU.ActiveCfg = Debug|Any CPU {9B91124C-66C3-4BD9-B29E-168C1ABB15AC}.Debug|Any CPU.Build.0 = Debug|Any CPU {9B91124C-66C3-4BD9-B29E-168C1ABB15AC}.Release|Any CPU.ActiveCfg = Release|Any CPU {9B91124C-66C3-4BD9-B29E-168C1ABB15AC}.Release|Any CPU.Build.0 = Release|Any CPU EndGlobalSection GlobalSection(SolutionProperties) = preSolution HideSolutionNode = FALSE EndGlobalSection GlobalSection(ExtensibilityGlobals) = postSolution SolutionGuid = {4576C9BB-A42D-46A8-9198-7E2982E122FA} EndGlobalSection EndGlobal

ByteScoutWebApiExample.vbproj

      
<?xml version="1.0" encoding="utf-8"?> <Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003"> <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" /> <PropertyGroup> <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration> <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform> <ProjectGuid>{9B91124C-66C3-4BD9-B29E-168C1ABB15AC}</ProjectGuid> <OutputType>Exe</OutputType> <StartupObject>ByteScoutWebApiExample.Module1</StartupObject> <RootNamespace>ByteScoutWebApiExample</RootNamespace> <AssemblyName>ByteScoutWebApiExample</AssemblyName> <FileAlignment>512</FileAlignment> <MyType>Console</MyType> <TargetFrameworkVersion>v4.0</TargetFrameworkVersion> </PropertyGroup> <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' "> <PlatformTarget>AnyCPU</PlatformTarget> <DebugSymbols>true</DebugSymbols> <DebugType>full</DebugType> <DefineDebug>true</DefineDebug> <DefineTrace>true</DefineTrace> <OutputPath>bin\Debug\</OutputPath> <DocumentationFile>ByteScoutWebApiExample.xml</DocumentationFile> <NoWarn>42016,41999,42017,42018,42019,42032,42036,42020,42021,42022</NoWarn> </PropertyGroup> <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' "> <PlatformTarget>AnyCPU</PlatformTarget> <DebugType>pdbonly</DebugType> <DefineDebug>false</DefineDebug> <DefineTrace>true</DefineTrace> <Optimize>true</Optimize> <OutputPath>bin\Release\</OutputPath> <DocumentationFile>ByteScoutWebApiExample.xml</DocumentationFile> <NoWarn>42016,41999,42017,42018,42019,42032,42036,42020,42021,42022</NoWarn> </PropertyGroup> <PropertyGroup> <OptionExplicit>On</OptionExplicit> </PropertyGroup> <PropertyGroup> <OptionCompare>Binary</OptionCompare> </PropertyGroup> <PropertyGroup> <OptionStrict>Off</OptionStrict> </PropertyGroup> <PropertyGroup> <OptionInfer>On</OptionInfer> </PropertyGroup> <ItemGroup> <Reference Include="Newtonsoft.Json, Version=10.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed, processorArchitecture=MSIL"> <HintPath>packages\Newtonsoft.Json.10.0.3\lib\net40\Newtonsoft.Json.dll</HintPath> </Reference> <Reference Include="System" /> <Reference Include="System.Data" /> <Reference Include="System.Deployment" /> <Reference Include="System.Xml" /> <Reference Include="System.Core" /> <Reference Include="System.Xml.Linq" /> <Reference Include="System.Data.DataSetExtensions" /> </ItemGroup> <ItemGroup> <Import Include="Microsoft.VisualBasic" /> <Import Include="System" /> <Import Include="System.Collections" /> <Import Include="System.Collections.Generic" /> <Import Include="System.Data" /> <Import Include="System.Diagnostics" /> <Import Include="System.Linq" /> <Import Include="System.Xml.Linq" /> </ItemGroup> <ItemGroup> <Compile Include="Module1.vb" /> <Compile Include="My Project\AssemblyInfo.vb" /> <Compile Include="My Project\Application.Designer.vb"> <AutoGen>True</AutoGen> <DependentUpon>Application.myapp</DependentUpon> </Compile> <Compile Include="My Project\Resources.Designer.vb"> <AutoGen>True</AutoGen> <DesignTime>True</DesignTime> <DependentUpon>Resources.resx</DependentUpon> </Compile> <Compile Include="My Project\Settings.Designer.vb"> <AutoGen>True</AutoGen> <DependentUpon>Settings.settings</DependentUpon> <DesignTimeSharedInput>True</DesignTimeSharedInput> </Compile> </ItemGroup> <ItemGroup> <EmbeddedResource Include="My Project\Resources.resx"> <Generator>VbMyResourcesResXFileCodeGenerator</Generator> <LastGenOutput>Resources.Designer.vb</LastGenOutput> <CustomToolNamespace>My.Resources</CustomToolNamespace> <SubType>Designer</SubType> </EmbeddedResource> </ItemGroup> <ItemGroup> <None Include="My Project\Application.myapp"> <Generator>MyApplicationCodeGenerator</Generator> <LastGenOutput>Application.Designer.vb</LastGenOutput> </None> <None Include="My Project\Settings.settings"> <Generator>SettingsSingleFileGenerator</Generator> <CustomToolNamespace>My</CustomToolNamespace> <LastGenOutput>Settings.Designer.vb</LastGenOutput> </None> <None Include="packages.config" /> </ItemGroup> <Import Project="$(MSBuildToolsPath)\Microsoft.VisualBasic.targets" /> </Project>

Module1.vb

      
Imports System.IO Imports System.Net Imports System.Threading Imports Newtonsoft.Json.Linq ' Cloud API asynchronous "PDF To TIFF" job example. ' Allows to avoid timeout errors when processing huge or scanned PDF documents. ' The following options are available through profiles: ' (JSON can be single/double-quoted and contain comments.) ' { ' "profiles": [ ' { ' "profile1": { ' "TextSmoothingMode": "HighQuality", // Valid values: "HighSpeed", "HighQuality" ' "VectorSmoothingMode": "HighQuality", // Valid values: "HighSpeed", "HighQuality" ' "ImageInterpolationMode": "HighQuality", // Valid values: "HighSpeed", "HighQuality" ' "RenderTextObjects": true, // Valid values: true, false ' "RenderVectorObjects": true, // Valid values: true, false ' "RenderImageObjects": true, // Valid values: true, false ' "RenderCurveVectorObjects": true, // Valid values: true, false ' "JPEGQuality": 85, // from 0 (lowest) to 100 (highest) ' "TIFFCompression": "LZW", // Valid values: "None", "LZW", "CCITT3", "CCITT4", "RLE" ' "RotateFlipType": "RotateNoneFlipNone", // RotateFlipType enum values from here: https://docs.microsoft.com/en-us/dotnet/api/system.drawing.rotatefliptype?view=netframework-2.0 ' "ImageBitsPerPixel": "BPP24", // Valid values: "BPP1", "BPP8", "BPP24", "BPP32" ' "OneBitConversionAlgorithm": "OtsuThreshold", // Valid values: "OtsuThreshold", "BayerOrderedDithering" ' "FontHintingMode": "Default", // Valid values: "Default", "Stronger" ' "NightMode": false // Valid values: true, false ' } ' } ' ] ' } Module Module1 ' The authentication key (API Key). ' Get your own by registering at https://app.pdf.co/documentation/api Const API_KEY As String = "***********************************" ' Direct URL of source PDF file. Const SourceFileUrl As String = "https://bytescout-com.s3.amazonaws.com/files/demo-files/cloud-api/pdf-to-image/sample.pdf" ' Comma-separated list of page indices (or ranges) to process. Leave empty for all pages. Example: '0,2-5,7-'. Const Pages As String = "" ' PDF document password. Leave empty for unprotected documents. Const Password As String = "" ' Destination TIFF file name Const DestinationFile As String = ".\result.tif" ' (!) Make asynchronous job Const Async As Boolean = True ' Advanced options Const Profiles As String = "{ 'profiles': [ { 'profile1': { 'TIFFCompression': 'CCITT4' } } ] }" Sub Main() ' Create standard .NET web client instance Dim webClient As WebClient = New WebClient() ' Set API Key webClient.Headers.Add("x-api-key", API_KEY) ' Prepare URL for `PDF To TIFF` API call Dim query As String = Uri.EscapeUriString(String.Format( "https://api.pdf.co/v1/pdf/convert/to/tiff?name={0}&password={1}&pages={2}&url={3}&async={4}&profiles={5}", Path.GetFileName(DestinationFile), Password, Pages, SourceFileUrl, Async, Profiles)) Try ' Execute request Dim response As String = webClient.DownloadString(query) ' Parse JSON response Dim json As JObject = JObject.Parse(response) If json("error").ToObject(Of Boolean) = False Then ' Asynchronous job ID Dim jobId As String = json("jobId").ToString() ' URL of generated TIFF file that will available after the job completion Dim resultFileUrl As String = json("url").ToString() ' Check the job status in a loop. ' If you don't want to pause the main thread you can rework the code ' to use a separate thread for the status checking and completion. Do Dim status As String = CheckJobStatus(jobId) ' Possible statuses: "working", "failed", "aborted", "success". ' Display timestamp and status (for demo purposes) Console.WriteLine(DateTime.Now.ToLongTimeString() + ": " + status) If status = "success" Then ' Download TIFF file webClient.DownloadFile(resultFileUrl, DestinationFile) Console.WriteLine("Generated TIFF file saved as ""{0}"" file.", DestinationFile) Exit Do ElseIf status = "working" Then ' Pause for a few seconds Thread.Sleep(3000) Else Console.WriteLine(status) Exit Do End If Loop Else Console.WriteLine(json("message").ToString()) End If Catch ex As WebException Console.WriteLine(ex.ToString()) End Try webClient.Dispose() Console.WriteLine() Console.WriteLine("Press any key...") Console.ReadKey() End Sub Function CheckJobStatus(jobId As String) As String Using webClient As WebClient = New WebClient() ' Set API Key webClient.Headers.Add("x-api-key", API_KEY) Dim url As String = "https://api.pdf.co/v1/job/check?jobid=" + jobId Dim response As String = webClient.DownloadString(url) Dim json As JObject = JObject.Parse(response) return Convert.ToString(json("status")) End Using End Function End Module

packages.config

      
<?xml version="1.0" encoding="utf-8"?> <packages> <package id="Newtonsoft.Json" version="10.0.3" targetFramework="net40" /> </packages>

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