META-INF.resources.bower_components.blueimp-load-image.js.load-image-exif.js Maven / Gradle / Ivy
/*
* JavaScript Load Image Exif Parser
* https://github.com/blueimp/JavaScript-Load-Image
*
* Copyright 2013, Sebastian Tschan
* https://blueimp.net
*
* Licensed under the MIT license:
* https://opensource.org/licenses/MIT
*/
/* global define, Blob */
;(function (factory) {
'use strict'
if (typeof define === 'function' && define.amd) {
// Register as an anonymous AMD module:
define(['./load-image', './load-image-meta'], factory)
} else if (typeof module === 'object' && module.exports) {
factory(require('./load-image'), require('./load-image-meta'))
} else {
// Browser globals:
factory(window.loadImage)
}
})(function (loadImage) {
'use strict'
loadImage.ExifMap = function () {
return this
}
loadImage.ExifMap.prototype.map = {
Orientation: 0x0112
}
loadImage.ExifMap.prototype.get = function (id) {
return this[id] || this[this.map[id]]
}
loadImage.getExifThumbnail = function (dataView, offset, length) {
if (!length || offset + length > dataView.byteLength) {
console.log('Invalid Exif data: Invalid thumbnail data.')
return
}
return loadImage.createObjectURL(
new Blob([dataView.buffer.slice(offset, offset + length)])
)
}
loadImage.exifTagTypes = {
// byte, 8-bit unsigned int:
1: {
getValue: function (dataView, dataOffset) {
return dataView.getUint8(dataOffset)
},
size: 1
},
// ascii, 8-bit byte:
2: {
getValue: function (dataView, dataOffset) {
return String.fromCharCode(dataView.getUint8(dataOffset))
},
size: 1,
ascii: true
},
// short, 16 bit int:
3: {
getValue: function (dataView, dataOffset, littleEndian) {
return dataView.getUint16(dataOffset, littleEndian)
},
size: 2
},
// long, 32 bit int:
4: {
getValue: function (dataView, dataOffset, littleEndian) {
return dataView.getUint32(dataOffset, littleEndian)
},
size: 4
},
// rational = two long values, first is numerator, second is denominator:
5: {
getValue: function (dataView, dataOffset, littleEndian) {
return (
dataView.getUint32(dataOffset, littleEndian) /
dataView.getUint32(dataOffset + 4, littleEndian)
)
},
size: 8
},
// slong, 32 bit signed int:
9: {
getValue: function (dataView, dataOffset, littleEndian) {
return dataView.getInt32(dataOffset, littleEndian)
},
size: 4
},
// srational, two slongs, first is numerator, second is denominator:
10: {
getValue: function (dataView, dataOffset, littleEndian) {
return (
dataView.getInt32(dataOffset, littleEndian) /
dataView.getInt32(dataOffset + 4, littleEndian)
)
},
size: 8
}
}
// undefined, 8-bit byte, value depending on field:
loadImage.exifTagTypes[7] = loadImage.exifTagTypes[1]
loadImage.getExifValue = function (
dataView,
tiffOffset,
offset,
type,
length,
littleEndian
) {
var tagType = loadImage.exifTagTypes[type]
var tagSize
var dataOffset
var values
var i
var str
var c
if (!tagType) {
console.log('Invalid Exif data: Invalid tag type.')
return
}
tagSize = tagType.size * length
// Determine if the value is contained in the dataOffset bytes,
// or if the value at the dataOffset is a pointer to the actual data:
dataOffset =
tagSize > 4
? tiffOffset + dataView.getUint32(offset + 8, littleEndian)
: offset + 8
if (dataOffset + tagSize > dataView.byteLength) {
console.log('Invalid Exif data: Invalid data offset.')
return
}
if (length === 1) {
return tagType.getValue(dataView, dataOffset, littleEndian)
}
values = []
for (i = 0; i < length; i += 1) {
values[i] = tagType.getValue(
dataView,
dataOffset + i * tagType.size,
littleEndian
)
}
if (tagType.ascii) {
str = ''
// Concatenate the chars:
for (i = 0; i < values.length; i += 1) {
c = values[i]
// Ignore the terminating NULL byte(s):
if (c === '\u0000') {
break
}
str += c
}
return str
}
return values
}
loadImage.parseExifTag = function (
dataView,
tiffOffset,
offset,
littleEndian,
data
) {
var tag = dataView.getUint16(offset, littleEndian)
data.exif[tag] = loadImage.getExifValue(
dataView,
tiffOffset,
offset,
dataView.getUint16(offset + 2, littleEndian), // tag type
dataView.getUint32(offset + 4, littleEndian), // tag length
littleEndian
)
}
loadImage.parseExifTags = function (
dataView,
tiffOffset,
dirOffset,
littleEndian,
data
) {
var tagsNumber, dirEndOffset, i
if (dirOffset + 6 > dataView.byteLength) {
console.log('Invalid Exif data: Invalid directory offset.')
return
}
tagsNumber = dataView.getUint16(dirOffset, littleEndian)
dirEndOffset = dirOffset + 2 + 12 * tagsNumber
if (dirEndOffset + 4 > dataView.byteLength) {
console.log('Invalid Exif data: Invalid directory size.')
return
}
for (i = 0; i < tagsNumber; i += 1) {
this.parseExifTag(
dataView,
tiffOffset,
dirOffset + 2 + 12 * i, // tag offset
littleEndian,
data
)
}
// Return the offset to the next directory:
return dataView.getUint32(dirEndOffset, littleEndian)
}
loadImage.parseExifData = function (dataView, offset, length, data, options) {
if (options.disableExif) {
return
}
var tiffOffset = offset + 10
var littleEndian
var dirOffset
var thumbnailData
// Check for the ASCII code for "Exif" (0x45786966):
if (dataView.getUint32(offset + 4) !== 0x45786966) {
// No Exif data, might be XMP data instead
return
}
if (tiffOffset + 8 > dataView.byteLength) {
console.log('Invalid Exif data: Invalid segment size.')
return
}
// Check for the two null bytes:
if (dataView.getUint16(offset + 8) !== 0x0000) {
console.log('Invalid Exif data: Missing byte alignment offset.')
return
}
// Check the byte alignment:
switch (dataView.getUint16(tiffOffset)) {
case 0x4949:
littleEndian = true
break
case 0x4d4d:
littleEndian = false
break
default:
console.log('Invalid Exif data: Invalid byte alignment marker.')
return
}
// Check for the TIFF tag marker (0x002A):
if (dataView.getUint16(tiffOffset + 2, littleEndian) !== 0x002a) {
console.log('Invalid Exif data: Missing TIFF marker.')
return
}
// Retrieve the directory offset bytes, usually 0x00000008 or 8 decimal:
dirOffset = dataView.getUint32(tiffOffset + 4, littleEndian)
// Create the exif object to store the tags:
data.exif = new loadImage.ExifMap()
// Parse the tags of the main image directory and retrieve the
// offset to the next directory, usually the thumbnail directory:
dirOffset = loadImage.parseExifTags(
dataView,
tiffOffset,
tiffOffset + dirOffset,
littleEndian,
data
)
if (dirOffset && !options.disableExifThumbnail) {
thumbnailData = { exif: {} }
dirOffset = loadImage.parseExifTags(
dataView,
tiffOffset,
tiffOffset + dirOffset,
littleEndian,
thumbnailData
)
// Check for JPEG Thumbnail offset:
if (thumbnailData.exif[0x0201]) {
data.exif.Thumbnail = loadImage.getExifThumbnail(
dataView,
tiffOffset + thumbnailData.exif[0x0201],
thumbnailData.exif[0x0202] // Thumbnail data length
)
}
}
// Check for Exif Sub IFD Pointer:
if (data.exif[0x8769] && !options.disableExifSub) {
loadImage.parseExifTags(
dataView,
tiffOffset,
tiffOffset + data.exif[0x8769], // directory offset
littleEndian,
data
)
}
// Check for GPS Info IFD Pointer:
if (data.exif[0x8825] && !options.disableExifGps) {
loadImage.parseExifTags(
dataView,
tiffOffset,
tiffOffset + data.exif[0x8825], // directory offset
littleEndian,
data
)
}
}
// Registers the Exif parser for the APP1 JPEG meta data segment:
loadImage.metaDataParsers.jpeg[0xffe1].push(loadImage.parseExifData)
// Adds the following properties to the parseMetaData callback data:
// * exif: The exif tags, parsed by the parseExifData method
// Adds the following options to the parseMetaData method:
// * disableExif: Disables Exif parsing.
// * disableExifThumbnail: Disables parsing of the Exif Thumbnail.
// * disableExifSub: Disables parsing of the Exif Sub IFD.
// * disableExifGps: Disables parsing of the Exif GPS Info IFD.
})
© 2015 - 2025 Weber Informatics LLC | Privacy Policy