InterpolationMode Enumeration

Summary

Interpolation mode support by LEADTOOLS.

Syntax
TypeScript
JavaScript
lt.Controls.InterpolationMode = { 
	none: 0, 
	resample: 1, 
	scaleToGray: 2 
} 
lt.Controls.InterpolationMode = { 
	none: 0, 
	resample: 1, 
	scaleToGray: 2 
} 
Members

0

None

(0) No interpolation. Default rendering by the platform.

1

Resample

(1) Use bilinear interpolation (resample) if the render operation needs to resize the image when zoom value is less than 1:1. This mode works for both bitonal (black/white) and color images.

2

ScaleToGray

(2) Enables grayscaling of bitonal images (such as black and white) if the render operation needs to resize the image when zoom value is less than 1:1. This mode produces slightly better result if the original image was black and white. However, in almost all cases, Resample produces similar results in quality and speed and should be used for all images.

Remarks

For more information, refer to Image Viewer Interpolation.

Example
InterpolationMode.ts
ImageViewer.ts
InterpolationMode.js
ImageViewer.js
InterpolationMode.html
import { ImageViewer_Example } from "../ImageViewer"; 
 
export class ImageViewer_InterpolationModeExample { 
   private viewerExample; 
   constructor() { 
      this.viewerExample = new ImageViewer_Example(this.run); 
   } 
 
   private run = (viewer: lt.Controls.ImageViewer) => { 
      // NOTE: in order for this example to work, you must include the image processing scripts in a directory: 
      lt.Controls.ImageViewer.imageProcessingLibrariesPath = "../LT"; 
 
      const _interpolationModeNames: string[] = ["None", "Resample", "ScaleToGray"]; 
      const _interpolationModeStatus: string[] = ["Started", "Completed", "Aborted", "Error"]; 
 
      const urls: string[] = [ 
         "http://demo.leadtools.com/images/png/ocr1.png", 
         "http://demo.leadtools.com/images/png/ocr2.png", 
         "http://demo.leadtools.com/images/png/ocr3.png", 
         "http://demo.leadtools.com/images/png/ocr4.png" 
      ]; 
 
 
      // Optional: tell the imageViewer to interpolate in parallel 
      viewer.interpolationRunMode = lt.Controls.InterpolationRunMode.parallel; 
 
      // Begin updating the imageviewer (stops rendering until endUpdate is called) 
      viewer.beginUpdate(); 
 
      viewer.items.clear(); 
      viewer.viewLayout = new lt.Controls.ImageViewerVerticalViewLayout(); 
      viewer.itemBorderThickness = 5; 
      viewer.itemMargin = lt.Controls.ControlPadding.createAll(5); 
 
      for (let urlIndex = 0; urlIndex < urls.length; urlIndex++) { 
         const item: lt.Controls.ImageViewerItem = new lt.Controls.ImageViewerItem(); 
         item.text = "Item" + urlIndex; 
         item.url = urls[urlIndex]; 
         viewer.items.add(item); 
      } 
      viewer.endUpdate(); 
 
      viewer.interpolation.add((sender, e) => { 
         let lines = []; 
         const itemIndex: number = viewer.items.indexOf(e.item); 
         lines.push("Item " + itemIndex + " " + _interpolationModeNames[e.mode] + ": " + _interpolationModeStatus[e.status]); 
         if (e.status === lt.Controls.InterpolationStatus.error) { 
            lines.push("  Error name:" + e.error.name + " message:" + e.error.message); 
         } 
         addLines(lines); 
      }); 
 
      const output = document.getElementById("output"); 
 
      // Add a select to show the interpolation options 
      const select = document.createElement("select"); 
      output.appendChild(select); 
 
      const interpolationModes: lt.Controls.InterpolationMode[] = [lt.Controls.InterpolationMode.none, lt.Controls.InterpolationMode.resample, lt.Controls.InterpolationMode.scaleToGray]; 
      for (let index = 0; index < interpolationModes.length; index++) { 
         const value: lt.Controls.InterpolationMode = interpolationModes[index]; 
         const option = document.createElement("option"); 
         option.innerHTML = _interpolationModeNames[value]; 
         select.appendChild(option); 
      } 
 
      select.addEventListener("change", () => { 
         const index: number = select.selectedIndex; 
         switch (index) { 
            case 0: 
               viewer.interpolationMode = lt.Controls.InterpolationMode.none; 
               break; 
            case 1: 
               viewer.interpolationMode = lt.Controls.InterpolationMode.resample; 
               break; 
            case 2: 
               viewer.interpolationMode = lt.Controls.InterpolationMode.scaleToGray; 
               break; 
         } 
      }); 
      // Start with resample 
      select.selectedIndex = lt.Controls.InterpolationMode.resample; 
      viewer.interpolationMode = lt.Controls.InterpolationMode.resample; 
 
      const textOutput = document.createElement("div"); 
      output.appendChild(textOutput); 
      const addLines = (messages) => { 
         const lines: string = messages.map((line) => { return "<p>" + line + "</p>" }); 
         textOutput.innerHTML += lines; 
      } 
   } 
} 
export class ImageViewer_Example { 
   // LEADTOOLS ImageViewer to be used with this example 
   protected imageViewer: lt.Controls.ImageViewer = null; 
   // Generic state value used by the examples 
   public timesClicked: number = 0; 
 
   constructor(callback?: (viewer: lt.Controls.ImageViewer) => void) { 
      // Set the LEADTOOLS license. Replace this with your actual license file 
      lt.RasterSupport.setLicenseUri("https://demo.leadtools.com/licenses/js/LEADTOOLSEVAL.txt", "EVAL", null); 
 
      // Create an image viewer inside the imageViewerDiv element 
      const imageViewerDiv = document.getElementById("imageViewerDiv"); 
      const createOptions: lt.Controls.ImageViewerCreateOptions = new lt.Controls.ImageViewerCreateOptions(imageViewerDiv); 
      this.imageViewer = new lt.Controls.ImageViewer(createOptions); 
      this.imageViewer.viewVerticalAlignment = lt.Controls.ControlAlignment.center; 
      this.imageViewer.viewHorizontalAlignment = lt.Controls.ControlAlignment.center; 
      this.imageViewer.autoCreateCanvas = true; 
 
      // Add Pan/Zoom interactive mode 
      // Click and drag to pan, CTRL-Click and drag to zoom in and out 
      this.imageViewer.interactiveModes.add(new lt.Controls.ImageViewerPanZoomInteractiveMode()); 
 
      // Load an image 
      this.imageViewer.imageUrl = "https://demo.leadtools.com/images/jpeg/cannon.jpg"; 
 
      this.imageViewer.zoom(lt.Controls.ControlSizeMode.fit, .9, this.imageViewer.defaultZoomOrigin); 
 
      const exampleButton = document.getElementById("exampleButton"); 
      exampleButton.addEventListener("click", () => { 
         this.timesClicked++; 
         // Run the example 
         if (callback) 
            callback(this.imageViewer); 
      }); 
   } 
} 
import { ImageViewer_Example } from "../ImageViewer"; 
 
export class ImageViewer_InterpolationModeExample { 
   viewerExample; 
   constructor() { 
      this.viewerExample = new ImageViewer_Example(this.run); 
   } 
 
   run = (viewer) => { 
      // NOTE: in order for this example to work, you must include the image processing scripts in a directory: 
      lt.Controls.ImageViewer.imageProcessingLibrariesPath = "../LT"; 
 
      const _interpolationModeNames = ["None", "Resample", "ScaleToGray"]; 
      const _interpolationModeStatus = ["Started", "Completed", "Aborted", "Error"]; 
 
      const urls = [ 
         "http://demo.leadtools.com/images/png/ocr1.png", 
         "http://demo.leadtools.com/images/png/ocr2.png", 
         "http://demo.leadtools.com/images/png/ocr3.png", 
         "http://demo.leadtools.com/images/png/ocr4.png" 
      ]; 
 
 
      // Optional: tell the imageViewer to interpolate in parallel 
      viewer.interpolationRunMode = lt.Controls.InterpolationRunMode.parallel; 
 
      // Begin updating the imageviewer (stops rendering until endUpdate is called) 
      viewer.beginUpdate(); 
 
      viewer.items.clear(); 
      viewer.viewLayout = new lt.Controls.ImageViewerVerticalViewLayout(); 
      viewer.itemBorderThickness = 5; 
      viewer.itemMargin = lt.Controls.ControlPadding.createAll(5); 
 
      for (let urlIndex = 0; urlIndex < urls.length; urlIndex++) { 
         const item = new lt.Controls.ImageViewerItem(); 
         item.text = "Item" + urlIndex; 
         item.url = urls[urlIndex]; 
         viewer.items.add(item); 
      } 
      viewer.endUpdate(); 
 
      viewer.interpolation.add((sender, e) => { 
         let lines = []; 
         const itemIndex = viewer.items.indexOf(e.item); 
         lines.push("Item " + itemIndex + " " + _interpolationModeNames[e.mode] + ": " + _interpolationModeStatus[e.status]); 
         if (e.status === lt.Controls.InterpolationStatus.error) { 
            lines.push("  Error name:" + e.error.name + " message:" + e.error.message); 
         } 
         addLines(lines); 
      }); 
 
      const output = document.getElementById("output"); 
 
      // Add a select to show the interpolation options 
      const select = document.createElement("select"); 
      output.appendChild(select); 
 
      const interpolationModes = [lt.Controls.InterpolationMode.none, lt.Controls.InterpolationMode.resample, lt.Controls.InterpolationMode.scaleToGray]; 
      for (let index = 0; index < interpolationModes.length; index++) { 
         const value = interpolationModes[index]; 
         const option = document.createElement("option"); 
         option.innerHTML = _interpolationModeNames[value]; 
         select.appendChild(option); 
      } 
 
      select.addEventListener("change", () => { 
         const index = select.selectedIndex; 
         switch (index) { 
            case 0: 
               viewer.interpolationMode = lt.Controls.InterpolationMode.none; 
               break; 
            case 1: 
               viewer.interpolationMode = lt.Controls.InterpolationMode.resample; 
               break; 
            case 2: 
               viewer.interpolationMode = lt.Controls.InterpolationMode.scaleToGray; 
               break; 
         } 
      }); 
      // Start with resample 
      select.selectedIndex = lt.Controls.InterpolationMode.resample; 
      viewer.interpolationMode = lt.Controls.InterpolationMode.resample; 
 
      const textOutput = document.createElement("div"); 
      output.appendChild(textOutput); 
      const addLines = (messages) => { 
         const lines = messages.map((line) => { return "<p>" + line + "</p>" }); 
         textOutput.innerHTML += lines; 
      } 
   } 
} 
export class ImageViewer_Example { 
   // LEADTOOLS ImageViewer to be used with this example 
   imageViewer = null; 
   // Generic state value used by the examples 
   timesClicked = 0; 
 
   constructor(callback) { 
      // Set the LEADTOOLS license. Replace this with your actual license file 
      lt.RasterSupport.setLicenseUri("https://demo.leadtools.com/licenses/js/LEADTOOLSEVAL.txt", "EVAL", null); 
 
      // Create an image viewer inside the imageViewerDiv element 
      const imageViewerDiv = document.getElementById("imageViewerDiv"); 
      const createOptions = new lt.Controls.ImageViewerCreateOptions(imageViewerDiv); 
      this.imageViewer = new lt.Controls.ImageViewer(createOptions); 
      this.imageViewer.viewVerticalAlignment = lt.Controls.ControlAlignment.center; 
      this.imageViewer.viewHorizontalAlignment = lt.Controls.ControlAlignment.center; 
      this.imageViewer.autoCreateCanvas = true; 
 
      // Add Pan/Zoom interactive mode 
      // Click and drag to pan, CTRL-Click and drag to zoom in and out 
      this.imageViewer.interactiveModes.add(new lt.Controls.ImageViewerPanZoomInteractiveMode()); 
 
      // Load an image 
      this.imageViewer.imageUrl = "https://demo.leadtools.com/images/jpeg/cannon.jpg"; 
 
      this.imageViewer.zoom(lt.Controls.ControlSizeMode.fit, .9, this.imageViewer.defaultZoomOrigin); 
 
      const exampleButton = document.getElementById("exampleButton"); 
      exampleButton.addEventListener("click", () => { 
         this.timesClicked++; 
         // Run the example 
         if (callback) 
            callback(this.imageViewer); 
      }); 
   } 
} 
<!doctype html> 
<html lang="en"> 
<title>Controls Example | InterpolationMode</title> 
 
<head> 
   <script src="https://code.jquery.com/jquery-2.2.4.min.js" 
      integrity="sha256-BbhdlvQf/xTY9gja0Dq3HiwQF8LaCRTXxZKRutelT44=" crossorigin="anonymous"></script> 
 
   <script src="../../LT/Leadtools.js"></script> 
   <script src="../../LT/Leadtools.Controls.js"></script> 
   <script src="../../LT/Leadtools.Annotations.Engine.js"></script> 
   <script src="../../LT/Leadtools.Annotations.Designers.js"></script> 
   <script src="../../LT/Leadtools.Annotations.Rendering.Javascript.js"></script> 
   <script src="../../LT/Leadtools.Annotations.Automation.js"></script> 
   <script src="../../LT/Leadtools.ImageProcessing.Main.js"></script> 
   <script src="../../LT/Leadtools.ImageProcessing.Color.js"></script> 
   <script src="../../LT/Leadtools.ImageProcessing.Core.js"></script> 
   <script src="../../LT/Leadtools.ImageProcessing.Effects.js"></script> 
   <script src="../../LT/Leadtools.Document.js"></script> 
   <script src="../../LT/Leadtools.Document.Viewer.js"></script> 
   <style> 
      body { 
         font-family: 'Segoe UI', sans-serif; 
      } 
 
      #imageViewerDiv { 
         border: 1px solid #888; 
         width: 500px; 
         height: 500px; 
         background-color: #eee; 
      } 
   </style> 
 
   <!-- All demo files are bundled and appended to the window --> 
   <script src="../../bundle.js" type="text/javascript"></script> 
</head> 
 
<body> 
   <p>Press and drag on the image to pan.</p> 
   <p>Hold down the control key and press and drag on the image or pinch with two fingers to zoom in and out.</p> 
   <div> 
      <button type="button" id="exampleButton">Run Example</button> 
   </div> 
   <div id="imageViewerDiv"></div> 
   <div id="output"></div> 
</body> 
 
<script> 
   window.onload = () => { 
      const example = new window.examples.ImageViewer.InterpolationMode(); 
 
   }; 
</script> 
</html> 
Requirements

Target Platforms

See Also

Reference

Leadtools.Controls Namespace

Help Version 23.0.2024.2.29
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Leadtools.Controls Assembly
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© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.