-
Notifications
You must be signed in to change notification settings - Fork 4
/
text-watermark.js
201 lines (166 loc) · 6.1 KB
/
text-watermark.js
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
/*
* @Package: text-watermark
* @Author: sahildua2305
* @Date: 2016-05-24 06:44:49
* @Last Modified by: Sahil Dua
* @Last Modified time: 2016-05-26 01:09:13
*/
'use strict';
var fs = require('fs');
var im = require('imagemagick');
var path = require('path');
var ratify = require('node-ratify');
// Default options for watermarking
var defaultOptions = {
"text" : "Sample Text Watermark",
"color" : "rgba(0,0,0,0.5)",
"scale" : "100%",
"rotation" : "dia",
"position" : "Center",
"override-image" : false
};
/**
* _parseOptions
* @param {Object} imageData image data as read by ImageMagick
* @param {String} source original image path
* @param {Object} options watermark options
* @return {Object} watermark final options to be passed to ImageMagick for watermarking
*/
function _parseOptions(imageData, source, options) {
var finalObj = {};
var width = imageData.width;
var height = imageData.height;
var watermarkText = ratify.isEmpty(options.text) ? defaultOptions.text : options.text;
var color = ratify.isEmpty(options.color) ? defaultOptions.color : options.color;
var scale = ratify.isEmpty(options.scale) ? defaultOptions.scale : options.scale;
var rotation = ratify.isEmpty(options.rotation) ? defaultOptions.rotation : options.rotation;
var position = defaultOptions.position;
var font = options.font;
var outputPath = null;
var angle = null;
// check if image needs to be overridden or not
// update the outputPath accordingly
if(options['override-image'] && ratify.isBoolean(options['override-image'])
&& options['override-image'].toString() === 'true') {
outputPath = source;
}
else {
outputPath = ratify.isEmpty(options.outputPath) ? (path.dirname(source) + "/watermark_" + path.basename(source)) : options.outputPath;
}
var pointWidth = width;
var pointHeight = height;
// check if given scale value is valid or not
// if it is, scale the pointWidth and pointHeight accordingly
if(scale.toString().indexOf("%") == -1) {
scale = defaultOptions.scale;
}
else {
var scaleFactor = (parseFloat(scale) / 100);
pointWidth *= scaleFactor;
pointHeight *= scaleFactor;
}
var pointSize = Math.sqrt(pointWidth * pointWidth + pointHeight * pointHeight) / watermarkText.length;
if(rotation.toString() == "dia") {
angle = (Math.atan(height / width) * (180 / Math.PI)) * -1;
}
else {
angle = parseInt(rotation.toString());
}
var args = [];
// original image path
args.push(source);
// size of final image
args.push("-size");
args.push(width + "x" + height);
// scale factor
args.push("-resize");
args.push(scale);
// set font, if passed in options
if(!ratify.isEmpty(font)) {
args.push("-font");
args.push(font);
}
// color of watermark text on the final image
args.push("-fill");
args.push(color);
// pointSize calculated on the basis of original image size and length of the watermark text
args.push("-pointsize");
args.push(pointSize);
// alignment of the watermark text
args.push("-gravity");
args.push(position);
// angle of the watermark text wrt to X-axis
args.push("-annotate");
args.push(angle);
// watermark text
args.push(watermarkText);
// path of final image with watermark path
args.push(outputPath);
finalObj.args = args;
finalObj.outputPath = outputPath;
return finalObj;
}
/**
* addWatermark
* @param {String} source original image path
* @param {Object} options watermark options
* @param {Function} callback callback function containing errors, if any
*/
function addWatermark(source, options, callback) {
var error;
// check for valid/invalid arguments
if((arguments.length < 2)
|| (arguments.length === 2 && !ratify.isFunction(arguments[1]))
|| (arguments.length > 2 && !ratify.isFunction(arguments[2]))) {
throw new Error('Text-Watermark::addWatermark : Invalid arguments');
}
else if(arguments.length === 2 && ratify.isFunction(arguments[1])) {
callback = arguments[1];
options = null;
}
// if no image source is found
if(!source || source == "") {
error = new Error('Text-Watermark::addWatermark : No image source');
return callback(error);
}
// check if source file exists at the specified path
fs.lstat(source, function(err, stats) {
if(err) {
error = new Error('Text-Watermark::addWatermark : Image file doesn\'t exist at source ' + source);
return callback(error);
}
else if(!stats.isFile()) {
error = new Error('Text-Watermark::addWatermark : Invalid image source at ' + source);
return callback(error);
}
else {
// use default options if options aren't properly specified
if(!options || typeof options !== 'object')
options = defaultOptions;
im.identify(source, function(err, imageData) {
if(err) {
error = new Error('Text-Watermark::addWatermark : Error while processing image file : ' + err);
return callback(error);
}
var finalObj = _parseOptions(imageData, source, options);
im.convert(finalObj.args, function(err, stdout) {
if(err) {
error = new Error('Text-Watermark::addWatermark : Error in applying watermark : ' + err);
return callback(error);
}
else {
console.log('Text-Watermark::addWatermark : Watermark applied. You can check the output file at : ' + finalObj.outputPath);
return callback(null);
}
});
});
}
});
return;
}
exports = module.exports = {
addWatermark : addWatermark,
version : JSON.parse(
require('fs').readFileSync(__dirname + '/package.json', 'utf-8')
).version
};