RecAPI is the core component of OmniPage Capture SDK 2025.1. For details on other API modules and CSDK in general, refer to the following documentation page: https://docshield.tungstenautomation.com/Portal/Products/en_US/OmniPageCaptureSDK/2025.1.0-m7NwYtqyAo/OmniPageCaptureSDK.htm
Throughout the RecAPI documentation we frequently refer to CSDK as Engine meaning all the modules of RecAPI.
The full functionality of the OmniPage Capture SDK is available only in Windows 64-bit operating systems. On other platforms (Windows 32-bit, Linux, Embedded Linux, Android, MacOS) there are different limitations. Documentation of some features list the supported platforms. If the description of a feature does not give such a list, the feature is supported on all platforms. Non-specified Windows means both 32 and 64-bit. Linux means desktop Linux on x64 processors. For MacOS OmniPage Capture SDK contains Universal binaries, which means an x86_64 version for Intel-based Macs and an arm64 version for Apple Silicons. There are some features not supporting arm64, they are said to support MacOS x64 only. For more information see the page Platforms.
RecAPI is a traditional, standard native "C" API separated into two layers: KernelAPI and RecAPIPlus. This simplifies the architecture and also makes the toolkit's offering more flexible: higher speed processing to simple text output or more thorough processing with formatted output. RecAPI also provides a base for RecAPI P/Invoke assembly for .NET managed applications.
A higher layer set of services is provided by IPRO and RecIPRO - with an updated object model. IPRO serves as the base for a range of visual components. To access IPRO and Visual Components documentation, use their own Help systems.
On Windows, RecAPI supports the macro _UNICODE. Thus depending on this macro User can use the RecAPI as an ANSI (current code page) or a Unicode API. On Linux and MacOS, RecAPI has an UTF-8 API.
Here are the main RecAPI components:
The KernelAPI part of RecAPI is useful when processing speed is a critical factor and/or there is no need for layout retention. This is the basic API with page-level functions. Therefore, this is very similar to APIs of earlier CSDK versions. We recommend that you use it for applications that do not require total format retention and rich output formats. KernelAPI generates its simple outputs directly from HPAGE. Here you can choose TXT, CSV, two different XML types, or PDF (image on text). Since page formatting is not present here, page-oriented processing on the KernelAPI level will be faster.
The RecAPIPlus part of RecAPI contains a user interface based on a documentoriented approach. You can implement functionality similar to that of OmniPage 2025 via just a handful of functions. When exporting multi-page documents you can use a series of output converters to provide layout retention quality equal to that in OmniPage 2025. Use the RecProcessPagesEx function to process many multi-page image files in one step. In this case, CSDK runs processing on several image preprocessing and OCR threads (multi-threading is supported on: Windows, Linux), enabling you to make the most of HyperThread and MultiCore processors and multi-processor computers. Getting high quality page layout retention and document level formatting adds somewhat to total processing time.
In both cases you can choose between three page parsing algorithms: Fast, Legacy or Standard. The latter is default and requires more time but delivers the best possible result, improving both recognition accuracy and format retention. Since the Standard page parsing package occupies some 20 MB, the Distribution Wizard offers it as a separate component.