source: other-projects/nz-flag-design/trunk/similarity-2d/flag-processing.js@ 29787

"use strict";

var progressVal = 0;

var show_progress = 5;

var start_hist_delay = 1000; // used to be 4000
var mini_delay = 300;


var hasLocalStorage = (typeof(Storage) !== "undefined"); // ****
//var hasLocalStorage = false;

var quantHSLHistogramArray;

//var saveOnServer=true;
var saveOnServer=false;
var retrieveFromServer=true;


function runlength_encode(int_array) {

    var array_len = int_array.length;

    if (array_len<2) {
    console.warn("runlength_encode(): unable to run-length encode array of length " + array_len);
    console.warn("returning null");
    return null;
    }

    var int_array_rle = new Array();


    var lock_val=int_array[0];
    var next_val=int_array[1];
    var i = 1;

    while (i<array_len) {
    var c=1;
    while (next_val==lock_val) {
        c++;
        var next_pos = i+c-1;
        if (next_pos<array_len) {
        next_val = int_array[next_pos];
        }
        else {
        // hit end of array
        break;
        }
    }
    // come out of a run-length sequence of same val
    // next_val is one past the run-length sequence

    int_array_rle.push(c);
    int_array_rle.push(lock_val);

    i+=c;

    if (i<array_len) {
        lock_val = next_val;
        next_val = int_array[i];
    }
    else {
        break;
    }
    }

    return int_array_rle;
}



function runlength_decode(int_array_rle) {

    var array_rle_len = int_array_rle.length;

    if (array_rle_len<2) {
    console.warn("runlength_decode(): unable to run-length decode array of length " + array_rle_len);
    console.warn("returning null");
    return null;
    }

    var int_array = new Array();
    for (var i=0; i<array_rle_len; i+=2){
    var rep = int_array_rle[i];
    var val = int_array_rle[i+1];
    for (var r=0; r<rep; r++) {
        int_array.push(val);
    }
    }

    return int_array;
}



function arrays_identical(int_array1, int_array2) {

    var array_len1 = int_array1.length;
    var array_len2 = int_array2.length;

    if (array_len1 != array_len2) {
    console.warn("arrays_identical(): array lengths differ, array1("+array_len1+") vs array2(" + array_len2 + ")");
    return false;
    }

    var all_ident = true;

    for (var i=0; i<array_len1; i++){
    if (int_array1[i] != int_array2[i]) {
        all_ident = false;
        break;
    }
    }

    return all_ident;
}


function drawImage(imageObj, canvasId) {
    var imgCanvas = document.getElementById(canvasId),
        context, imageData, data,
        imageX = 0, imageY = 0,
        imageWidth = imageObj.width,
        imageHeight = imageObj.height;

    context = imgCanvas.getContext('2d');
    context.drawImage(imageObj, imageX, imageY, imageWidth, imageHeight);
    imageData = context.getImageData(imageX, imageY, imageWidth, imageHeight);

    return imageData;
}

function createHSLHistogram(imageObj, quant)
{
    var i;

    if (!$('#hsl_canvas').length) {
    $('<canvas>', {id: 'hsl_canvas'}).hide().appendTo('body');
    }

    var 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;
    }

/*
    if (saveOnServer) {
    console.log("Saving HSV quantized histogram on server: " + imageObj.title)
    //console.log("outputArray = " + JSON.stringify(outputArray));

    var jsonFilename = imageObj.title + ".json";
    var data = { jsonFilename: jsonFilename, jsonData: JSON.stringify(outputArray)};

    console.log("Saving colour histogram data for " + imageObj.title);
    $.ajax({
        type: "POST",
        url: "../similarity-2d/save-json-data.jsp",
        data: data
    });
    }
*/

    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;

    if (img_list_len==0) {
    return;
    }
    else if (img_list_len>show_progress) {
    $progressArea.slideDown();
    }

    img_list.sort();

    var root_img_re = /^.*\/(.*?)\..*?$/;

    var progress_step = 100.0 / img_list_len;
    
    var callback_count = 0;
    
    var i;
    for (i=0; i<img_list.length; i++) {
    var img_url     = img_list[i];
    var img_matches = root_img_re.exec(img_url);
    var title       = img_matches[1];
    
    var imageObj = new Image();
    imageObj.onload = function() {
        callback_count++;
        progressVal += progress_step;   
        $progressBar.progressbar('value',progressVal);
        
        if (callback_count == img_list_len) {
        if (img_list_len>show_progress) {
            progressVal = 100;
            $progressBar.progressbar('value',progressVal);
            //$progressArea.slideUp();

            // Now move on and start computing colour histograms
            setTimeout(function() 
                   {  doneDisplayFlags(img_list,$progressArea,$progressBar); }
                   ,start_hist_delay);
        }
        }
    };


    /*
$("h2").live('mousedown', function(e) { 
   if( (e.which == 1) ) {
     alert("left button");
   }if( (e.which == 3) ) {
     alert("right button");
   }else if( (e.which == 2) ) {
      alert("middle button"); 
   }
   e.preventDefault();
}).live('contextmenu', function(e){
 e.preventDefault();
});
    */

    imageObj.onclick = function(e) {
        // 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);
        }

        if (e.which == 1 ) {
        // Left => use in comparison pair
        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;
        }
        }
        else if (e.which == 2) {
        // Middle => fix on this and do similarity with everything else
            var fix_id = this.id;
        e.preventDefault();
        }

    };
    
    
    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

    if (retrieveFromServer) {
        // see if it is stored on the server 
        console.log("Retrieving stored colour histogram for " + imageObj.title + " ...");
        $.ajax({
        async: false,
        dataType: "json",
        url: "../similarity-2d/json-data/" + imageObj.title + ".json",
        success: function(data) {
            console.log("... success");
            // 'data' is the array of integer vals we want
            imageObj.quantHSLHist = data;
        },
        error: function() {
            console.log("... not stored on server");
            // not stored on the server (currently)
            // => need to compute it
            imageObj.quantHSLHist = createHSLHistogram(imageObj,16);
            //console.log(imageObj.quantHSLHist);

        }
        });
    }
    else {
        imageObj.quantHSLHist = createHSLHistogram(imageObj,16);
    }

    }

    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)
               }
           ,mini_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();
    }

    doneComputingHistograms(img_list_len);
    }
}


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)
               }
           ,mini_delay // any time delay causes break in 'rendering' thread, even 0!
           );
    
}

function doneComputingHistograms(img_list_len)
{
    quantHSLHistogramArray = new Array(img_list_len);
    for (var i=0; i<img_list_len; i++) {
    var flag_id = "flag-img-" + i;
    var imageObj = document.getElementById(flag_id);
    quantHSLHistogramArray[i] = imageObj.quantHSLHist;
    } 
    var json_hist_data = JSON.stringify(quantHSLHistogramArray);

    if (hasLocalStorage) {
    // build up quantHSLHistogramArray from all the images

    console.log("Storing computed HSL histograms in localStorage");
    localStorage.quantHSLHistogramArray = json_hist_data;
    }

    if (saveOnServer) {
    // run-length encode data, so less to send
    var quantHSLHistogramArrayRLE = new Array(img_list_len);
    for (var i=0; i<img_list_len; i++) {
        //console.log("rle encoding ... i = " + i);
        quantHSLHistogramArrayRLE[i] = runlength_encode(quantHSLHistogramArray[i])

        //var test_decode_array = runlength_decode(quantHSLHistogramArrayRLE[i]);
        //console.log("Checking decoded array: " + arrays_identical(test_decode_array,quantHSLHistogramArray[i]));
    }


    var json_hist_data_rle = JSON.stringify(quantHSLHistogramArrayRLE);

    var json_filename = "all-hsv-histograms-rle.json";
    var data = { jsonFilename: json_filename, jsonData: json_hist_data_rle};
    
    console.log("Saving colour histogram data for all flags");
    $.ajax({
        type: "POST",
        url: "../similarity-2d/save-json-data.jsp",
        data: data      
    });
    }
}

function doneDisplayFlags(img_list,$progressArea,$progressBar)
{
    console.log("doneDisplayFlags()");

    var needToComputeHistograms = true;

    if (hasLocalStorage) {

    if (localStorage.quantHSLHistogramArray) {

        console.log("Retrieving quantized HSL histograms from local storage");

        var stored_hist_array = JSON.parse(localStorage["quantHSLHistogramArray"]);
        if (stored_hist_array.length == img_list.length) {
        // Assume if the number of images process hasn't changed, then neither
        // has the stored historgram values

        quantHSLHistogramArray = stored_hist_array;

        var i;
        for (i=0; i<img_list.length; i++) {
            var flag_id = "flag-img-" + i;
            var imageObj = document.getElementById(flag_id);
            imageObj.quantHSLHist = quantHSLHistogramArray[i];
        } 

        needToComputeHistograms = false;
        }
        else {
        console.log("Different number of images detected => regenerating");
        }
    }
    }

    if (needToComputeHistograms) {

    if (retrieveFromServer) {
        // before computing histograms from scratch, see if resulting data stored on server

        console.log("Retrieving stored colour histgram data for all flags ...");
        $.ajax({
        async: true,
        dataType: "json",
        url: "../similarity-2d/json-data/all-hsv-histograms-rle.json",
        success: function(rle_data) {
            console.log("... success");
            if (rle_data.length != img_list.length) {
            console.log("Stored histogram data out of date with flag list.");
            // what is stored on the sever differed to the number of images displayed
            computeFlagHistograms(img_list,$progressArea,$progressBar);
            }
            else {
            var img_list_len = img_list.length;
            quantHSLHistogramArray = new Array(img_list_len);
            
            // Need to rle decode each entry in this array
            for (var i=0; i<img_list_len; i++) {
                quantHSLHistogramArray[i] = runlength_decode(rle_data[i]);
                var flag_id = "flag-img-" + i;
                var imageObj = document.getElementById(flag_id);
                imageObj.quantHSLHist = quantHSLHistogramArray[i];

            }

            needToComputeHistograms = false;

            $progressArea.slideUp();
            doneComputingHistograms(img_list.length);

            }
        },
        error: function() {
            console.log("... not stored on server");
            computeFlagHistograms(img_list,$progressArea,$progressBar);
        }
        });


    }
    else {
        computeFlagHistograms(img_list,$progressArea,$progressBar);
    }
    }
    else {
    $progressArea.slideUp();
    doneComputingHistograms(img_list.length);
    }
}

function rankBySimilarity(imageData,x_dim,y_dim)
{
    // quantizedColourHistogramComparison(quant_colour_hist1,quant_colour_hist2) 

}