IronOCR How-Tos Detect Page Rotation How to Detect Page Rotation Chaknith Bin Updated:June 22, 2025 Determining page rotation involves identifying the degree of rotation applied to a page within a document. This process specifically determines if the page has been rotated clockwise or counterclockwise by angles of 0, 90, 180, and 270 degrees. This information is crucial for rendering or processing the document accurately, ensuring that pages are displayed or printed in their correct orientations. IronOCR takes page rotation detection to the next level. Once rotation has been detected, the returned value can be used in combination with the Rotate method to adjust the image to the correct orientation. Get started with IronOCR Start using IronOCR in your project today with a free trial. First Step: Start for Free How to Detect Page Rotation Download a C# library to detect page rotation Import the PDF document and images for reading Use the DetectPageOrientation method to detect rotation for all pages Access the RotationAngle property to correct page rotation Access the HighConfidence property to handle edge cases Detect Page Rotation Example After loading the document, you can utilize the DetectPageOrientation method to identify the rotation of each page. This method supports degrees of 0, 90, 180, and 270. For skewed images, the Deskew image correction method can be used. Subsequently, rotate the image back to its original orientation using the degree returned from the function. Let's proceed with a sample PDF. [i:{(This function performs well when the document is text-dense.)}] :path=/static-assets/ocr/content-code-examples/how-to/detect-page-rotation-detect-page-rotation.cs using IronOcr; using System; using var input = new OcrInput(); // Load PDF document input.LoadPdf("Clockwise90.pdf"); // Detect page rotation var results = input.DetectPageOrientation(); // Ouput result foreach(var result in results) { Console.WriteLine(result.PageNumber); Console.WriteLine(result.HighConfidence); Console.WriteLine(result.RotationAngle); } Imports IronOcr Imports System Private input = New OcrInput() ' Load PDF document input.LoadPdf("Clockwise90.pdf") ' Detect page rotation Dim results = input.DetectPageOrientation() ' Ouput result For Each result In results Console.WriteLine(result.PageNumber) Console.WriteLine(result.HighConfidence) Console.WriteLine(result.RotationAngle) Next result $vbLabelText $csharpLabel Understanding the Result PageNumber: Indicates the zero-based index of the page. RotationAngle: Provides the corrective rotation angle in degrees. This angle can be applied to the Rotate method to return the image to right-side-up rotation. For example, if the image is rotated 90 degrees clockwise, the angle returned will be 270, which can then be passed to the Rotate method as input.Rotate(RotationAngle). HighConfidence: Indicates the level of confidence in the orientation result, which helps in handling edge cases more effectively. Frequently Asked Questions How can I detect page rotation in a document using C#? You can use IronOCR's DetectPageOrientation method to identify the rotation of pages in a document. This method can detect rotations at angles of 0, 90, 180, and 270 degrees. What steps are involved in correcting page rotation in IronOCR? First, use the DetectPageOrientation method to determine the rotation angle. Then, apply the Rotate method with the RotationAngle property to correct the page's orientation. How does IronOCR handle skewed document images? For skewed images, IronOCR provides a Deskew method to correct the skew before applying rotation corrections. What properties help ensure accurate page rotation detection? The RotationAngle property indicates the angle needed for correction, while the HighConfidence property shows the confidence level in the detected orientation, helping manage edge cases. How can I ensure my document pages are displayed correctly using IronOCR? Use the DetectPageOrientation method to find the rotation angle and apply the Rotate method using this angle to correct the page orientation. Can IronOCR handle text-dense documents effectively? Yes, IronOCR's DetectPageOrientation function is designed to perform well even with text-dense documents. What does the PageNumber property indicate in IronOCR? The PageNumber property indicates the zero-based index of the page being processed, helping track orientation corrections across multiple pages. How do I correct a document that is both rotated and skewed? First, use IronOCR's Deskew method to correct any skew, then apply the DetectPageOrientation method followed by the Rotate method using the detected RotationAngle to correct any rotation. What is the importance of detecting page rotation in document processing? Detecting page rotation ensures documents are rendered and processed accurately, maintaining correct orientations for display or printing, which is critical for applications like OCR. Can IronOCR handle documents with multiple rotation angles in a single document? Yes, IronOCR can detect and correct different rotation angles for each page in a document using the DetectPageOrientation method. Chaknith Bin Chat with engineering team now Software Engineer Chaknith works on IronXL and IronBarcode. He has deep expertise in C# and .NET, helping improve the software and support customers. 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