diff --git a/_articles/faq/load-pdf-files.md b/_articles/faq/load-pdf-files.md index 7af3f46c..95faa3be 100644 --- a/_articles/faq/load-pdf-files.md +++ b/_articles/faq/load-pdf-files.md @@ -7,39 +7,43 @@ keywords: Dynamic Web TWAIN, Addon, load pdf/a breadcrumbText: How can I load PDF/A files into the Dynamic Web TWAIN SDK? description: How can I load PDF/A files into the Dynamic Web TWAIN SDK? date: 2021-12-01 01:09:41 +0800 -last_modified: 2025-12-10 15:53:54 +0800 +last_modified: 2025-12-11 14:20:54 +0800 --- # Addon ## How can I load PDF/A files into the Dynamic Web TWAIN SDK? -Dynamic Web TWAIN can load PDF/A files, but whether the PDF Rasterizer add-on is required depends on the content of the PDF/A file: +Dynamic Web TWAIN can load PDF/A files. Whether you need the **[PDF Rasterizer Add-on (PDFR)](https://www.dynamsoft.com/web-twain/pdf-to-image-javascript/)** depends entirely on the contents of the PDF/A document: -- If the PDF/A contains text or vector graphics, it must be rasterized, and therefore requires the PDF Rasterizer add-on. -- If the PDF/A contains only raster images, it can be loaded without the PDF Rasterizer. +- If the PDF/A contains **text or vector graphics**, rasterization is required → **PDFR license needed**. +- If the PDF/A contains **only raster images**, the file can be loaded **without** the PDFR add-on. -You can programmatically check whether a file needs rasterization using [`IsRasterizationRequired()`](/_articles/info/api/Addon_PDF.html#israsterizationrequired): +> [!NOTE] +> **Looking for information about generating PDF/A files?** +> +> Starting from Dynamic Web TWAIN 19.3, PDF/A creation is supported. +> +> See: [How can I generate PDF/A files?](/_articles/faq/generate-pdf-files.md) + +### How to check whether rasterization is required + +You can programmatically detect whether a given PDF/A file requires rasterization before loading it: ```javascript DWTObject.Addon.PDF.IsRasterizationRequired(path); // returns true or false ``` -When enabled, the add-on automatically rasterizes PDF/A documents into images when they are loaded into the viewer. - -> [!NOTE] -> **Looking for information about generating PDF/A files?** -> Starting from Dynamic Web TWAIN 19.3, PDF/A creation is supported. -> See: [How can I generate PDF/A files?](/_articles/faq/generate-pdf-files.md) +If this method returns **`true`**, the SDK will need the PDFR to process the file. +### When rasterization actually happens -### When is PDF Rasterizer used? +Dynamic Web TWAIN performs rasterization **only when necessary**. If [`IsRasterizationRequired()`](/_articles/info/api/Addon_PDF.md#israsterizationrequired) returns **`true`** and the PDF Rasterizer license is configured, the SDK automatically rasterizes the PDF into images using the reader settings you specify. -Once the PDF Rasterizer (`PDFR`) is configured, it automatically rasterizes the file *only when needed*. -If rasterization is required, the PDF is converted into one or more images at the specified resolution (default **200 DPI**). +The rasterization behavior—including resolution (default **200 DPI**) and other rendering parameters—can be customized through [`SetReaderOptions()`](/_articles/info/api/Addon_PDF.md#setreaderoptions). -Rasterization may occur when using any of the following APIs (including drag-and-drop): +Rasterization may occur when using any of these APIs (including drag-and-drop): - [ `LoadImage()` ](/_articles/info/api/WebTwain_IO.md#loadimage) - [ `LoadImageEx()` ](/_articles/info/api/WebTwain_IO.md#loadimageex) - [ `LoadImageFromBase64Binary()` ](/_articles/info/api/WebTwain_IO.md#loadimagefrombase64binary) @@ -50,9 +54,3 @@ Rasterization may occur when using any of the following APIs (including drag-and - [ `HTTPDownloadEx()` ](/_articles/info/api/WebTwain_IO.md#httpdownloadex) - [ `HTTPDownloadThroughPost()` ](/_articles/info/api/WebTwain_IO.md#httpdownloadthroughpost) - [ `HTTPDownloadDirectly()` ](/_articles/info/api/WebTwain_IO.md#httpdownloaddirectly) - -### Important Change in v19.3 -Previous versions of Dynamic Web TWAIN did **not** support exporting PDF/A files. -As of **19.3**, you can now: -- Load PDF/A files (with or without the PDF Rasterizer, depending on content), and -- Generate PDF/A files.