1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
|
<!DOCTYPE html>
<html lang="en">
<head>
<title>HTJ2K decoding in the browser using Webassembly</title>
<meta charset="UTF-8">
<!-- This is a test of libopenjph javascript
<script type="text/javascript" src="libopenjph_simd.js"></script>
-->
<script src="https://unpkg.com/wasm-feature-detect/dist/umd/index.js"></script>
</head>
<body>
<h1>HTJ2K decoding in the browser using WASM (with or without SIMD)</h1>
<pre style="font-size:16px" id='simd_message'>
This webpage employs WASM SIMD if your browser supports it -->
</pre>
<pre style="font-size:16px">
Decoding the full resolution image.
</pre>
<canvas id="mycanvas" width="512" height="512"></canvas>
<br>
<pre id="time" style="font-size: 16px">Decode time: </pre>
<h1>HTJ2K progressive decoding to the actual image resolution</h1>
<pre style="font-size:16px">
This example shows that one source image can be used for multiple reconstructed resolutions.
The client/browser can decide, depending on the rendering resolution, the number of bytes to load and decode for a given image.
Note: Below each image, we display the number of decoded bytes
</pre>
<table>
<tr>
<td></td>
<td style="text-align:center; vertical-align:bottom; height:512px"><canvas id='r1c5' width=48px"> </canvas></td>
<td style="text-align:center; vertical-align:bottom; height:512px"><canvas id='r1c4' width=48px"> </canvas></td>
<td style="text-align:center; vertical-align:bottom; height:512px"><canvas id='r1c3' width=64px"> </canvas></td>
<td style="text-align:center; vertical-align:bottom; height:512px"><canvas id='r1c2' width=128px"></canvas></td>
<td style="text-align:center; vertical-align:bottom; height:512px"><canvas id='r1c1' width=256px"></canvas></td>
<td style="text-align:center; vertical-align:bottom; height:512px"><canvas id='r1c0' width=512px"></canvas></td>
</tr>
<tr>
<td style="text-align:center; width:64px"> <pre>Decoded<br/>Bytes<br><pre>Time</pre></br></pre></td>
<td style="text-align:center; width:48px"> <pre>826<br/>bytes<br><pre id='t1c5'> ms</pre></br></pre></td>
<td style="text-align:center; width:48px"> <pre>2312<br/>bytes<br><pre id='t1c4'> ms</pre></br></pre></td>
<td style="text-align:center; width:64px"> <pre>5977<br/>bytes<br><pre id='t1c3'> ms</pre></br></pre></td>
<td style="text-align:center; width:128px"><pre>13022<br/>bytes<br><pre id='t1c2'> ms</pre></br></pre></td>
<td style="text-align:center; width:256px"><pre>22005<br/>bytes<br><pre id='t1c1'> ms</pre></br></pre></td>
<td style="text-align:center; width:512px"><pre>32553<br/>bytes<br><pre id='t1c0'> ms</pre></br></pre></td>
</tr>
</table>
<h1>HTJ2K progressive decoding to full resolution (downloaded once, decoded many ways)</h1>
<pre style="font-size:16px">
This example shows the progressive decoding of JPEG2000.
Image quality improves as more data arrives. This is better than waiting for the whole image to arrive before decoding it.
Note: Below each image, we display the number of decoded bytes and PSNR.
</pre>
<table>
<tr>
<td><canvas id='r2c5' width="512px" height="512px"></canvas></td>
<td><canvas id='r2c4' width="512px" height="512px"></canvas></td>
</tr>
<tr>
<td><pre style="text-align:center">Decoded Bytes: 826 bytes</pre></td>
<td><pre style="text-align:center">Decoded Bytes: 2312 bytes</pre></td>
</tr>
<tr>
<td><pre style="text-align:center">PSNR: 16.96 dB</pre></td>
<td><pre style="text-align:center">PSNR: 18.25 dB</pre></td>
</tr>
<tr>
<td><pre id='t2c5' style="text-align:center">Decode Time: </pre></td>
<td><pre id='t2c4' style="text-align:center">Decode Time: </pre></td>
</tr>
<tr>
<td><canvas id='r2c3' width="512px" height="512px"></canvas></td>
<td><canvas id='r2c2' width="512px" height="512px"></canvas></td>
</tr>
<tr>
<td><pre style="text-align:center">Decoded Bytes: 5977 bytes</pre></td>
<td><pre style="text-align:center">Decoded Bytes: 13022 bytes</pre></td>
</tr>
<tr>
<td><pre style="text-align:center">PSNR: 21.21 dB</pre></td>
<td><pre style="text-align:center">PSNR: 25.46 dB</pre></td>
</tr>
<tr>
<td><pre id='t2c3' style="text-align:center">Decode Time: </pre></td>
<td><pre id='t2c2' style="text-align:center">Decode Time: </pre></td>
</tr>
<tr>
<td><canvas id='r2c1' width="512px" height="512px"></canvas></td>
<td><canvas id='r2c0' width="512px" height="512px"></canvas></td>
</tr>
<tr>
<td><pre style="text-align:center">Decoded Bytes: 22005 bytes</pre></td>
<td><pre style="text-align:center">Decoded Bytes: 32553 bytes</pre></td>
</tr>
<tr>
<td><pre style="text-align:center">PSNR: 30.82 dB</pre></td>
<td><pre style="text-align:center">PSNR: 37.13 dB</pre></td>
</tr>
<tr>
<td><pre id='t2c1' style="text-align:center">Decode Time: </pre></td>
<td><pre id='t2c0' style="text-align:center">Decode Time: </pre></td>
</tr>
</table>
<script>
function display_image(Module, data, canvas_name, skip_res_for_data, skip_res_for_recon, txt_ele_name, pre_text)
{
create_j2c_data = Module.cwrap('create_j2c_data', 'number');
init_j2c_data = Module.cwrap('init_j2c_data', 'void', ['number', 'number', 'number']);
get_j2c_width = Module.cwrap('get_j2c_width', 'number', ['number', 'number']);
get_j2c_height = Module.cwrap('get_j2c_height', 'number', ['number', 'number']);
get_j2c_bit_depth = Module.cwrap('get_j2c_bit_depth', 'number', ['number', 'number']);
get_j2c_is_signed = Module.cwrap('get_j2c_is_signed', 'number', ['number', 'number']);
get_j2c_num_components = Module.cwrap('get_j2c_num_components', 'number', ['number']);
get_j2c_downsampling_x = Module.cwrap('get_j2c_downsampling_x', 'number', ['number', 'number']);
get_j2c_downsampling_y = Module.cwrap('get_j2c_downsampling_y', 'number', ['number', 'number']);
parse_j2c_data = Module.cwrap('parse_j2c_data', 'void', ['number']);
restrict_input_resolution = Module.cwrap('restrict_input_resolution', 'void', ['number', 'number', 'number']);
enable_resilience = Module.cwrap('enable_resilience', 'void', ['number']);
pull_j2c_line = Module.cwrap('pull_j2c_line', 'number', ['number']);
release_j2c_data = Module.cwrap('release_j2c_data', 'void', ['number']);
var t0 = performance.now();
j2c = create_j2c_data();
const array = new Uint8Array(data, 0, data.byteLength);
var buffer = Module._malloc(array.length);
Module.writeArrayToMemory(array, buffer);
enable_resilience(j2c);
init_j2c_data(j2c, buffer, array.length);
restrict_input_resolution(j2c, skip_res_for_data, skip_res_for_recon);
var width = get_j2c_width(j2c, 0) | 0; //component 0
var height = get_j2c_height(j2c, 0) | 0; //component 0
var num_comps = get_j2c_num_components(j2c) | 0;
var bit_depth = get_j2c_bit_depth(j2c, 0) | 0; //component 0
var is_signed = get_j2c_is_signed(j2c, 0) == 1; //component 0
parse_j2c_data(j2c);
var canvas = document.getElementById(canvas_name);
canvas.width = width;
canvas.height = height;
var ctx = canvas.getContext("2d");
var cimg = ctx.createImageData(width, height);
var shift = (bit_depth >= 8 ? bit_depth - 8 : 0) | 0;
var half = (bit_depth > 8 ? (1<<(shift-1)) : 0) | 0;
var heap = Module["HEAP32"];
var dst = cimg.data;
if (num_comps == 1)
{
for (var y = 0|0; y < height; y = y + 1|0)
{
//src is an address in memory, but since we are
// dealing with integers (i.e, each entry is 4 bytes
// away from the previous sample, we need to divide by 4
var src = pull_j2c_line(j2c) >> 2;
var didx = y * width * 4;
for (var x = 0|0; x < width; x = x + 1|0)
{
var val = (heap[src + x] + half) >> shift;
dst[didx + x * 4 ] = val;
dst[didx + x * 4 + 1] = val;
dst[didx + x * 4 + 2] = val;
dst[didx + x * 4 + 3] = 255;
}
}
}
else if (num_comps == 3)
{
for (var y = 0|0; y < height; y = y + 1|0)
{
for (var c = 0|0; c < num_comps; c = c + 1|0)
{
//src is an address in memory, but since we are
// dealing with integers (i.e, each entry is 4 bytes
// away from the previous sample, we need to divide by 4
var src = pull_j2c_line(j2c) >> 2;
var didx = y * width * 4 + c;
for (var x = 0|0; x < width; x = x + 1|0)
{
var val = (heap[src + x] + half) >> shift;
dst[didx + x * 4] = val;
}
}
var didx = y * width * 4 + 3;
for (var x = 0|0; x < width; x = x + 1|0)
dst[didx + x * 4] = 255;
}
}
else
console.log('Unsupported number of components');
release_j2c_data(j2c);
ctx.putImageData(cimg, 0, 0);
Module._free(buffer);
var t1 = performance.now();
document.getElementById(txt_ele_name).innerText = pre_text + (t1 - t0).toFixed(2) + " ms";
}
async function load_and_display_images(Module)
{
var request = new XMLHttpRequest;
request.open("GET", "test.j2c", true);
request.responseType = "arraybuffer";
request.onload = function (event) {
if (request.status == 200)
{
display_image(Module, this.response, 'mycanvas', 0, 0, 'time', 'Decode Time: ' );
for (var i = 0; i <= 5; ++i)
display_image(Module, this.response, 'r1c' + i, i, i, 't1c' + i, '');
for (var i = 0; i <= 5; ++i)
display_image(Module, this.response, 'r2c' + i, i, 0, 't2c' + i, 'Decode Time: ');
}
};
request.send(null);
}
async function load_simd_module() {
const openjph = await import('./libopenjph_simd.js');
const Module = await openjph.default();
load_and_display_images(Module);
}
async function load_generic_module() {
const openjph = await import('./libopenjph.js');
const Module = await openjph.default();
load_and_display_images(Module);
}
wasmFeatureDetect.simd().then(simdSupported => {
txt = document.getElementById('simd_message').innerText.slice(0, -1);
if (simdSupported) {
document.getElementById('simd_message').innerText = txt + "SIMD is detected. \n";
load_simd_module();
} else {
document.getElementById('simd_message').innerText = txt + "SIMD is not detected. \n";
load_generic_module();
}
});
</script>
</body>
</html>
|
