minor tweaks...

Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>
This commit is contained in:
Alex A. Naanou 2019-05-14 03:55:35 +03:00
parent e7444df938
commit 94e2537891
2 changed files with 254 additions and 2 deletions

View File

@ -0,0 +1,252 @@
<!DOCTYPE html>
<html>
<style>
</style>
<script src="../ext-lib/jquery.js"></script>
<script src="../ext-lib/jquery-ui.js"></script>
<script src="../lib/jli.js"></script>
<script>
Filters = {}
// as input takes an HTML Image object...
Filters.getPixels = function(img, w, h){
var w = w || img.width
var h = h || img.height
var c = this.getCanvas(w, h)
var ctx = c.getContext('2d')
if(img == null){
ctx.rect(0, 0, w, h)
ctx.fillStyle = "black"
ctx.fill()
} else {
ctx.drawImage(img, 0, 0, w, h)
}
return ctx.getImageData(0,0,c.width,c.height)
}
Filters.setPixels = function(c, data, w, h){
c.width = data.width
c.height = data.height
var ctx = c.getContext('2d')
ctx.putImageData(data, 0, 0)
//ctx.drawImage(data, 0, 0, w, h)
}
Filters.getCanvas = function(w, h){
var c = document.createElement('canvas')
c.width = w
c.height = h
return c
}
Filters.filterImage = function(filter, image, var_args){
var args = [this.getPixels(image)]
for(var i=2; i<arguments.length; i++){
args.push(arguments[i])
}
return filter.apply(null, args)
}
Filters.grayscale = function(pixels, args){
var d = pixels.data
for(var i=0; i<d.length; i+=4){
var r = d[i]
var g = d[i+1]
var b = d[i+2]
// CIE luminance for the RGB
// The human eye is bad at seeing red and blue, so we de-emphasize them.
var v = 0.2126*r + 0.7152*g + 0.0722*b
d[i] = d[i+1] = d[i+2] = v
}
return pixels
}
// XXX need to resize this...
Filters.histogram = function(pixels, mode){
mode = mode || 'luminance'
var w = 255
var h = 255
// output buffer...
var out = this.getPixels(null, w, h)
// pixel hit buffer...
var count = []
var od = out.data
var d = pixels.data
// get the stats...
for(var i=0; i<d.length; i+=4){
var r = d[i]
var g = d[i+1]
var b = d[i+2]
if(mode == 'luminance'){
var v = Math.round(0.2126*r + 0.7152*g + 0.0722*b) * 4
count[v] = count[v+1] = count[v+2] = (count[v] || 0) + 1
} else {
if(mode == 'color' || mode == 'R'){
count[r*4] = (count[r*4] || 0) + 1
}
if(mode == 'color' || mode == 'G'){
count[g*4+1] = (count[g*4+1] || 0) + 1
}
if(mode == 'color' || mode == 'B'){
count[b*4+2] = (count[b*4+2] || 0) + 1
}
}
}
var m = 255 / Math.max(...count.filter(function(){ return true }))
var pos = function(i, value){
return (
// horixontal position...
i*4
// value vertical offset...
+ (255-Math.round(value*m))*w*4) }
count.forEach(function(v, i){
var j = pos(i/4, v)
od[j] = 255
// correct for blue visibility...
if(mode != 'luminance' && (i-2)%4 == 0){
od[j-1] = od[j-2] = 180
}
})
return out
}
Filters.waveform = function(pixels, mode){
mode = mode || 'luminance'
var w = pixels.width
// normalize pixel ratio...
var m = (1/pixels.height)*255
var offsetTop = 0
var offsetBottom = 0
// output buffer...
var out = this.getPixels(null,
w,
offsetTop + 255 + offsetBottom)
// pixel hit buffer...
var count = []
var od = out.data
var d = pixels.data
var pos = function(i, value){
return (
// top margin...
offsetTop*w*4
// horixontal position...
+ i%(w*4)
// value vertical offset...
+ (255-Math.round(value))*w*4) }
var gain = 100
for(var i=0; i<d.length; i+=4){
var r = d[i]
var g = d[i+1]
var b = d[i+2]
var c
var j
if(mode == 'luminance'){
// CIE luminance for RGB
var v = 0.2126*r + 0.7152*g + 0.0722*b
c = count[j = pos(i, v)] = (count[j] || 0) + m
od[j] = od[j+1] = od[j+2] = c * gain
} else {
if(mode == 'color' || mode == 'R'){
j = pos(i, r)
c = count[j] = (count[j] || 0) + m
od[j] = c * gain
}
if(mode == 'color' || mode == 'G'){
j = pos(i, g) + 1
c = count[j] = (count[j] || 0) + m
od[j] = c * gain
}
if(mode == 'color' || mode == 'B'){
j = pos(i, b) + 2
c = count[j] = (count[j] || 0) + m
od[j] = c * gain
}
}
}
return out
}
var WAVEFORM_SIZE = 1000
var waveform = function(img, canvas, mode){
var d = Filters.getPixels(img, WAVEFORM_SIZE)
var w = Filters.waveform(d, mode)
Filters.setPixels(canvas, w)
}
var HISTOGRAM_SIZE = 1000
var histogram = function(img, canvas, mode){
var d = Filters.getPixels(img)
var w = Filters.histogram(d, mode)
Filters.setPixels(canvas, w)
}
var start = function(){
waveform(document.getElementById('input'), document.getElementById('waveform'), 'color')
histogram(document.getElementById('input'), document.getElementById('histogram'), 'color')
}
</script>
<body>
<img id="input" src="../images/splash-800x500.jpg" onload="start()"/>
<br>
<canvas id="waveform"></canvas>
<br>
<button onclick="waveform(getElementById('input'), getElementById('waveform'), 'luminance')">Luminance</button>
<button onclick="waveform(getElementById('input'), getElementById('waveform'), 'color')">Color</button>
<button onclick="waveform(getElementById('input'), getElementById('waveform'), 'R')">R</button>
<button onclick="waveform(getElementById('input'), getElementById('waveform'), 'G')">G</button>
<button onclick="waveform(getElementById('input'), getElementById('waveform'), 'B')">B</button>
<br>
<canvas id="histogram"></canvas>
<br>
<button onclick="histogram(getElementById('input'), getElementById('histogram'), 'luminance')">Luminance</button>
<button onclick="histogram(getElementById('input'), getElementById('histogram'), 'color')">Color</button>
<button onclick="histogram(getElementById('input'), getElementById('histogram'), 'R')">R</button>
<button onclick="histogram(getElementById('input'), getElementById('histogram'), 'G')">G</button>
<button onclick="histogram(getElementById('input'), getElementById('histogram'), 'B')">B</button>
</body>
</html>

View File

@ -198,6 +198,7 @@ Items.ListTitle = function(){}
//
//
// XXX should this be simply a shorthand to .trigger(..) ???
// XXX ASAP: should call the handlers with actual items and not the arguments...
var makeEventMethod = function(event, handler){
return function(item){
// register handler...
@ -1785,7 +1786,7 @@ var BaseBrowserPrototype = {
// XXX need a way to extend these to:
// - be able to trigger an external (DOM) event...
// - be able to be triggered from an external (DOM) event...
// XXX should we trigger the item's focus events???
// XXX should call the handlers with actual items and not the arguments...
// XXX should this return the focused item????
focus: makeItemEventMethod('focus', function(evt, items){
// NOTE: if we got multiple matches we care only about the first one...
@ -1801,7 +1802,6 @@ var BaseBrowserPrototype = {
blur: makeItemEventMethod('blur', function(evt, items){
items.forEach(function(item){
delete item.focused }) }),
// XXX should we trigger the item's select events???
select: makeItemEventMethod('select', function(evt, items){
items.forEach(function(item){
item.selected = true }) }),