OpenCV-wasm-browser, removed external dependencies

functions.js

@@ -51,5 +51,5 @@ export async function organizePages(snapshot, operation, customOrderString) {
 }
 
 export async function removeBlankPages(snapshot, whiteThreashold) {
-    return dependantRemoveBlankPages(snapshot, whiteThreashold, PDFJS, OpenCV);
+    return dependantRemoveBlankPages(snapshot, whiteThreashold, PDFJS, OpenCV, PDFLib);
 }

public/dep/downloadjs_1.4.7.js

@@ -0,0 +1,167 @@
+//download.js v4.2, by dandavis; 2008-2016. [MIT] see http://danml.com/download.html for tests/usage
+// v1 landed a FF+Chrome compat way of downloading strings to local un-named files, upgraded to use a hidden frame and optional mime
+// v2 added named files via a[download], msSaveBlob, IE (10+) support, and window.URL support for larger+faster saves than dataURLs
+// v3 added dataURL and Blob Input, bind-toggle arity, and legacy dataURL fallback was improved with force-download mime and base64 support. 3.1 improved safari handling.
+// v4 adds AMD/UMD, commonJS, and plain browser support
+// v4.1 adds url download capability via solo URL argument (same domain/CORS only)
+// v4.2 adds semantic variable names, long (over 2MB) dataURL support, and hidden by default temp anchors
+// https://github.com/rndme/download
+
+(function (root, factory) {
+	if (typeof define === 'function' && define.amd) {
+		// AMD. Register as an anonymous module.
+		define([], factory);
+	} else if (typeof exports === 'object') {
+		// Node. Does not work with strict CommonJS, but
+		// only CommonJS-like environments that support module.exports,
+		// like Node.
+		module.exports = factory();
+	} else {
+		// Browser globals (root is window)
+		root.download = factory();
+  }
+}(this, function () {
+
+	return function download(data, strFileName, strMimeType) {
+
+		var self = window, // this script is only for browsers anyway...
+			defaultMime = "application/octet-stream", // this default mime also triggers iframe downloads
+			mimeType = strMimeType || defaultMime,
+			payload = data,
+			url = !strFileName && !strMimeType && payload,
+			anchor = document.createElement("a"),
+			toString = function(a){return String(a);},
+			myBlob = (self.Blob || self.MozBlob || self.WebKitBlob || toString),
+			fileName = strFileName || "download",
+			blob,
+			reader;
+			myBlob= myBlob.call ? myBlob.bind(self) : Blob ;
+	  
+		if(String(this)==="true"){ //reverse arguments, allowing download.bind(true, "text/xml", "export.xml") to act as a callback
+			payload=[payload, mimeType];
+			mimeType=payload[0];
+			payload=payload[1];
+		}
+
+
+		if(url && url.length< 2048){ // if no filename and no mime, assume a url was passed as the only argument
+			fileName = url.split("/").pop().split("?")[0];
+			anchor.href = url; // assign href prop to temp anchor
+		  	if(anchor.href.indexOf(url) !== -1){ // if the browser determines that it's a potentially valid url path:
+        		var ajax=new XMLHttpRequest();
+        		ajax.open( "GET", url, true);
+        		ajax.responseType = 'blob';
+        		ajax.onload= function(e){ 
+				  download(e.target.response, fileName, defaultMime);
+				};
+        		setTimeout(function(){ ajax.send();}, 0); // allows setting custom ajax headers using the return:
+			    return ajax;
+			} // end if valid url?
+		} // end if url?
+
+
+		//go ahead and download dataURLs right away
+		if(/^data:([\w+-]+\/[\w+.-]+)?[,;]/.test(payload)){
+		
+			if(payload.length > (1024*1024*1.999) && myBlob !== toString ){
+				payload=dataUrlToBlob(payload);
+				mimeType=payload.type || defaultMime;
+			}else{			
+				return navigator.msSaveBlob ?  // IE10 can't do a[download], only Blobs:
+					navigator.msSaveBlob(dataUrlToBlob(payload), fileName) :
+					saver(payload) ; // everyone else can save dataURLs un-processed
+			}
+			
+		}else{//not data url, is it a string with special needs?
+			if(/([\x80-\xff])/.test(payload)){			  
+				var i=0, tempUiArr= new Uint8Array(payload.length), mx=tempUiArr.length;
+				for(i;i<mx;++i) tempUiArr[i]= payload.charCodeAt(i);
+			 	payload=new myBlob([tempUiArr], {type: mimeType});
+			}		  
+		}
+		blob = payload instanceof myBlob ?
+			payload :
+			new myBlob([payload], {type: mimeType}) ;
+
+
+		function dataUrlToBlob(strUrl) {
+			var parts= strUrl.split(/[:;,]/),
+			type= parts[1],
+			decoder= parts[2] == "base64" ? atob : decodeURIComponent,
+			binData= decoder( parts.pop() ),
+			mx= binData.length,
+			i= 0,
+			uiArr= new Uint8Array(mx);
+
+			for(i;i<mx;++i) uiArr[i]= binData.charCodeAt(i);
+
+			return new myBlob([uiArr], {type: type});
+		 }
+
+		function saver(url, winMode){
+
+			if ('download' in anchor) { //html5 A[download]
+				anchor.href = url;
+				anchor.setAttribute("download", fileName);
+				anchor.className = "download-js-link";
+				anchor.innerHTML = "downloading...";
+				anchor.style.display = "none";
+				document.body.appendChild(anchor);
+				setTimeout(function() {
+					anchor.click();
+					document.body.removeChild(anchor);
+					if(winMode===true){setTimeout(function(){ self.URL.revokeObjectURL(anchor.href);}, 250 );}
+				}, 66);
+				return true;
+			}
+
+			// handle non-a[download] safari as best we can:
+			if(/(Version)\/(\d+)\.(\d+)(?:\.(\d+))?.*Safari\//.test(navigator.userAgent)) {
+				if(/^data:/.test(url))	url="data:"+url.replace(/^data:([\w\/\-\+]+)/, defaultMime);
+				if(!window.open(url)){ // popup blocked, offer direct download:
+					if(confirm("Displaying New Document\n\nUse Save As... to download, then click back to return to this page.")){ location.href=url; }
+				}
+				return true;
+			}
+
+			//do iframe dataURL download (old ch+FF):
+			var f = document.createElement("iframe");
+			document.body.appendChild(f);
+
+			if(!winMode && /^data:/.test(url)){ // force a mime that will download:
+				url="data:"+url.replace(/^data:([\w\/\-\+]+)/, defaultMime);
+			}
+			f.src=url;
+			setTimeout(function(){ document.body.removeChild(f); }, 333);
+
+		}//end saver
+
+
+
+
+		if (navigator.msSaveBlob) { // IE10+ : (has Blob, but not a[download] or URL)
+			return navigator.msSaveBlob(blob, fileName);
+		}
+
+		if(self.URL){ // simple fast and modern way using Blob and URL:
+			saver(self.URL.createObjectURL(blob), true);
+		}else{
+			// handle non-Blob()+non-URL browsers:
+			if(typeof blob === "string" || blob.constructor===toString ){
+				try{
+					return saver( "data:" +  mimeType   + ";base64,"  +  self.btoa(blob)  );
+				}catch(y){
+					return saver( "data:" +  mimeType   + "," + encodeURIComponent(blob)  );
+				}
+			}
+
+			// Blob but not URL support:
+			reader=new FileReader();
+			reader.onload=function(e){
+				saver(this.result);
+			};
+			reader.readAsDataURL(blob);
+		}
+		return true;
+	}; /* end download() */
+}));

public/exampleWorkflows.js

@@ -136,4 +136,18 @@ export const imposeOnly = {
             operations: []
         }
     ]
+}
+
+// Split a document up into multiple documents
+export const removeBlankPagesOnly = {
+    outputOptions: {
+        zip: false
+    },
+    operations: [
+        {
+            type: "removeBlankPages",
+            values: { "whiteThreashold": 10 },
+            operations: []
+        }
+    ]
 }

public/functions.js

@@ -1,5 +1,6 @@
 // PDFLib gets importet via index.html script-tag
-// TODO: OpenCV wasm js from browser
+const OpenCV = { cv: cv } // OPENCV gets importet as cv via index.html script-tag
+// PDFJS as pdfjsLib via index.html script-tag
 import * as pdfcpuWraopper from "./wasm/pdfcpu-wrapper-browser.js";
 
 import { extractPages as dependantExtractPages } from "./functions/extractPages.js";
@@ -50,5 +51,5 @@ export async function organizePages(snapshot, operation, customOrderString) {
 }
 
 export async function removeBlankPages(snapshot, whiteThreashold) {
-    return dependantRemoveBlankPages(snapshot, whiteThreashold, PDFLib, OpenCV);
+    return dependantRemoveBlankPages(snapshot, whiteThreashold, pdfjsLib, OpenCV, PDFLib);
 }

public/functions/removeBlankPages.js

@@ -1,10 +1,11 @@
-export async function removeBlankPages(snapshot, whiteThreashold, PDFJS, OpenCV) {
+export async function removeBlankPages(snapshot, whiteThreashold, PDFJS, OpenCV, PDFLib) {
     
     const pdfDoc = await PDFJS.getDocument(snapshot).promise;
 
     const emptyPages = [];
     for (let i = 1; i <= pdfDoc.numPages; i++) {
         const page = await pdfDoc.getPage(i);
+        console.log("Checking images");
 
         if(!await hasText(page)) {
             console.log("Found text on Page, page is not empty");

public/index.html

@@ -6,10 +6,12 @@
     <title>Document</title>
 
     <!--TODO: Remove External Dependencies-->
-    <script src="https://unpkg.com/pdf-lib@1.17.1/dist/pdf-lib.min.js"></script>
-    <script src="https://unpkg.com/downloadjs@1.4.7"></script>
+    <script src="/dep/pdf-lib.min.js"></script>
+    <script src="/dep/downloadjs_1.4.7.js"></script>
 
+    <script src="/dep/pdf.min.js"></script>
     <script src="/wasm/browserfs.min.js"></script>
+    <script src="/wasm/opencv/opencv_3_4_custom_O3.js"></script>
 
     <script src="index.js" type="module"></script>
 </head>

public/index.js

@@ -40,4 +40,4 @@ import * as Functions from "./functions.js";
             download(result.buffer, result.fileName, "application/pdf");
         });
     });
-})(exampleWorkflows.imposeOnly);
+})(exampleWorkflows.removeBlankPagesOnly);