Changeset 29626 for other-projects

Timestamp:

2014-12-14T23:05:21+13:00 (9 years ago)

Author:

davidb

Message:

Next phase of developing focusing on colour histogram similarity. C# code by JoJo now ported to JavaScript using colour/get-pixel example developed by Dave Nichols.

Location:

other-projects/nz-flag-design/trunk/similarity-2d

Files:

• display-flags.jsp (modified) (1 diff)
• flag-processing.js (modified) (3 diffs)

other-projects/nz-flag-design/trunk/similarity-2d/display-flags.jsp

@@ -10 +10 @@
     <script src="../js/jquery-ui-1.11.2.smoothness/jquery-ui.js"></script>
 
+    <script src="js-lib/Colour.js"></script>
     <script src="flag-processing.js"></script>
 

other-projects/nz-flag-design/trunk/similarity-2d/flag-processing.js

@@ -2 +2 @@
 var progressVal = 0;
 
+var show_progress = 5;
+
+var timeout_delay = 100;
 
 function drawImage(imageObj, canvasId) {
@@ -10 +13 @@
         imageWidth = imageObj.width,
         imageHeight = imageObj.height;
+
     context = imgCanvas.getContext('2d');
     context.drawImage(imageObj, imageX, imageY, imageWidth, imageHeight);
     imageData = context.getImageData(imageX, imageY, imageWidth, imageHeight);
-    //data = imageData.data;
+
     return imageData;
 }
 
+function createHSLHistogram(imageObj, quant)
+{
+    var i;
+
+    if (!$('#hsl_canvas').length) {
+    $('<canvas>', {id: 'hsl_canvas'}).hide().appendTo('body');
+    }
+
+    imageData = drawImage(imageObj,'hsl_canvas');
+
+    var outputLength = quant * quant * quant;
+    var outputArray = new Array(outputLength);
+    for (i=0; i<outputLength; i++) {
+    outputArray[i] = 0;
+    }
+
+    var total = 0.0;
+            
+    var log2 = Math.log(2);
+
+    //calculate value to shift by (log base 2)
+        
+    var shift_sat = Math.floor(Math.log(quant)/log2);
+    var shift_hue = Math.floor(Math.log(quant*quant)/log2);
+
+    //console.log("bit-shift sat = " + shift_sat);
+    //console.log("bit-shift hue = " + shift_hue);
+
+    var data = imageData.data;
+
+    //Loop through each pixel
+    var y,p;
+    for (y=0,p=0; y<imageObj.height; y++) {
+    var x;
+    for (x=0; x<imageObj.width; x++,p+=4) {
+        // convert 4 byte data value into a colour pixel
+        var rgb_c = new RGBColour(data[p],data[p+1],data[p+2],data[p+3]/255.0);
+        var hsl = new rgb_c.getHSL();
+
+        // express h,s and b in the range 0..1
+
+        var h = hsl.h / 360.0;
+        var s = hsl.s / 100.0;
+        var b = hsl.l / 100.0;
+        
+        var result =    (Math.floor(h * (quant - 1)) << shift_hue) 
+                  | (Math.floor(s * (quant - 1)) << shift_sat) 
+                  |  Math.floor(b * (quant - 1));
+
+        //number of opaque pixels
+        var count = hsl.a;  // 'a' is naturally in the range 0..1
+            
+        //add to the total number of opaque pixels
+        total += count;
+
+        //add the frequency of each colour to the histogram
+        outputArray[result] += count;                    
+    }
+    }
+
+    //Normalise the histogram, based on the number of opaque pixels
+    for (i=0; i<outputArray.length; i++) {
+    outputArray[i] = outputArray[i] / total;
+    }
+
+    return outputArray;
+}
+
+var flag_comparison_array = Array(2);
+var clicked_on_count = 0;
+
+function quantizedColourHistogramComparison(quant_colour_hist1,quant_colour_hist2) 
+{
+    // Assumes both histograms are of the same length
+
+    var i;
+    var quant_product = 0.0;
+
+    //Loop through and compare the histograms
+    for (i=0; i<quant_colour_hist1.length; i++) {
+    //take the overlap
+    quant_product += Math.min(quant_colour_hist1[i], quant_colour_hist2[i]);
+
+    // consider replacing with abs for difference
+    }
+
+    alert("Product for HSL histogram: " + quant_product);
+
+}
+
 
 function displayFlags(img_list,$displayDiv,$progressArea,$progressBar)
 {
     var img_list_len = img_list.length;
-    var show_progress = 5;
 
     if (img_list_len==0) {
@@ -43 +136 @@
     
     var imageObj = new Image();
-    imageObj.onload = function () {
+    imageObj.onload = function() {
         callback_count++;
         progressVal += progress_step;   
         $progressBar.progressbar('value',progressVal);
         
-        //image1Data = drawImage(this, "canvas1");
-        
         if (callback_count == img_list_len) {
         if (img_list_len>show_progress) {
-            $progressArea.slideUp();
+            progressVal = 100;
+            $progressBar.progressbar('value',progressVal);
+            //$progressArea.slideUp();
+
+            // Now move on and start computing colour histograms
+            setTimeout(function() 
+                   {  computeFlagHistograms(img_list,$progressArea,$progressBar); }
+                   ,timeout_delay);
         }
         }
     };
+
+    imageObj.onclick = function() {
+        // Store result of HSL quantization in the image object/tag
+        if (!this.quantHSLHist) {
+        // Only need to compute this if it is not already stored in the object/tag
+        this.quantHSLHist = createHSLHistogram(this,16);
+        console.log(this.quantHSLHist);
+        }
+        flag_comparison_array[clicked_on_count] = this.quantHSLHist;
+
+        clicked_on_count++;
+        if (clicked_on_count==2) {
+        // trigger comparison
+        quantizedColourHistogramComparison(flag_comparison_array[0],flag_comparison_array[1]);
+        clicked_on_count=0;
+        }
+    };
+    
     
     imageObj.src   = img_url;
     imageObj.title = title;
-    
+    imageObj.id    = "flag-img-" + i;
+
     $displayDiv.append(imageObj);
     }
 }
 
-
-
+function computeFlagHistogramChain(chain_count, img_list_len,
+                   progressVal, progress_step,
+                   $progressArea,$progressBar)
+{
+    var flag_id = "flag-img-" + chain_count;
+    console.log("Processing Image ID: " + flag_id);
+    var imageObj = document.getElementById(flag_id);
+
+    if (!imageObj.quantHSLHist) {
+    // Only need to compute this if it is not
+    // already stored in the object/tag
+    imageObj.quantHSLHist = createHSLHistogram(imageObj,16);
+    //console.log(imageObj.quantHSLHist);
+    }
+
+    if (chain_count < img_list_len-1) {
+    progressVal += progress_step;   
+    $progressBar.progressbar('value',progressVal);
+
+    setTimeout(function()
+           { computeFlagHistogramChain(chain_count+1,img_list_len,
+                           progressVal, progress_step,
+                           $progressArea,$progressBar)
+               }
+           ,timeout_delay // any time delay causes break in 'rendering' thread, even 0!
+           );
+
+    }
+    else {
+    $progressArea.find('span:first').text("Done.");
+    if (img_list_len>show_progress) {
+        progressVal = 100;
+        $progressBar.progressbar('value',progressVal);
+        $progressArea.slideUp();
+    }
+    }
+}
+
+function computeFlagHistograms(img_list,$progressArea,$progressBar)
+{
+    var img_list_len = img_list.length;
+
+
+    if (img_list_len==0) {
+    $progressArea.find('span:first').text("Empty list: no computation needed.");
+    return;
+    }
+
+    $progressArea.find('span:first').text("Computing histograms:");
+    progressVal = 0;
+
+    if (img_list_len>show_progress) {
+    $progressArea.slideDown();
+    }
+
+    var progress_step = 100.0 / img_list_len;
+ 
+    // Start the chaining process
+    setTimeout(function() 
+           { computeFlagHistogramChain(0,img_list_len,
+                       progressVal, progress_step,
+                       $progressArea,$progressBar)
+               }
+           ,timeout_delay // any time delay causes break in 'rendering' thread, even 0!
+           );
+    
+}