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Update Readme.html.
author David Barts <davidb@stashtea.com>
date Thu, 16 Apr 2020 20:49:40 -0700
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8 h1, h2, h3, h4, h5, h6 { font-family: "Avenir Next", sans-serif; } 8 h1, h2, h3, h4, h5, h6 { font-family: "Avenir Next", sans-serif; }
9 pre, code, kbd, samp { font-family: "Menlo", monospace; font-size: 85%; } 9 pre, code, kbd, samp { font-family: "Menlo", monospace; font-size: 85%; }
10 </style> 10 </style>
11 </head> 11 </head>
12 <body> 12 <body>
13 <h1>Indroducing ExifWasher</h1> 13 <h1>Introducing JpegWasher</h1>
14 <h2>Executive Summary</h2> 14 <h2>Executive Summary</h2>
15 <p>This program makes it easy to remove metadata from the digital images you 15 <p>This program makes it easy to remove metadata from the digital images you
16 create.</p> 16 create.</p>
17 <h2>What is “Metadata” and Why Would I Want to Remove It?</h2> 17 <h2>What is “Metadata” and Why Would I Want to Remove It?</h2>
18 <p>You may not realize it, but image files can (and typically do!) contain 18 <p>You may not realize it, but image files can (and typically do!) contain
24 evils of slavery, child labor, poverty, war, and imperialism have all been 24 evils of slavery, child labor, poverty, war, and imperialism have all been
25 documented photographically, and such photographs have often proved 25 documented photographically, and such photographs have often proved
26 instrumental in helping to motivate social change.</p> 26 instrumental in helping to motivate social change.</p>
27 <p>Because of the metadata they contain, digital photographs contain data 27 <p>Because of the metadata they contain, digital photographs contain data
28 which has been used to determine who took them, and in some cases to exact 28 which has been used to determine who took them, and in some cases to exact
29 retribution against their photographers. ExifWasher makes it easy to see 29 retribution against those photographers. JpegWasher makes it easy to see
30 and remove the privacy-compromising metadata in your images.</p> 30 and remove the privacy-compromising metadata in your images.</p>
31 <p>Even if your images are not of such a sensitive nature, that extra data 31 <p>Even if your images are not of such a sensitive nature, that extra data
32 takes up space. It is not uncommon for a 100 KiB image to contain 20 KiB 32 takes up space. It is not uncommon for a 100 KiB image to contain 20 KiB
33 of metadata in it; if that image is on a web page, that makes for 20 KiB 33 of metadata in it; if that image is on a web page, that makes for 20 KiB
34 of wasted network usage each time the image is sent.</p> 34 of wasted network usage each time the image is sent.</p>
35 <h2>What Makes ExifWasher Different from Other Metadata Editors?</h2> 35 <h2>What Makes JpegWasher Different from Other Metadata Editors?</h2>
36 <p>Simply put, it is designed to <em>safely</em> remove <em>unimportant</em> 36 <p>Simply put, it is designed to <em>safely</em> remove <em>unimportant</em>
37 metadata.</p> 37 metadata from JPEG files.</p>
38 <p>There are plenty of general-purpose image metadata editors out there, and 38 <p>There are plenty of general-purpose image metadata editors out there, and
39 these tools can be employed to remove unimportant metadata. The trouble 39 these tools can be employed to remove unimportant metadata. The trouble
40 is, they are not user-friendly: it is up to you, the user, to know which 40 is, they are not user-friendly: it is up to you, the user, to know which
41 metadata are unimportant, and to delete it.</p> 41 metadata are unimportant, and to delete it.</p>
42 <p>There can be literally <em>hundreds</em> of bits of metadata in an 42 <p>There can be literally <em>hundreds</em> of bits of metadata in an
49 out there for cleaning the metadata out of image files, but they 49 out there for cleaning the metadata out of image files, but they
50 inevitably delete <em>all</em> metadata, resulting in files that often 50 inevitably delete <em>all</em> metadata, resulting in files that often
51 display improperly. Also of concern, many of these “tools” are actually 51 display improperly. Also of concern, many of these “tools” are actually
52 online services. If you’re concerned about your privacy, why would you 52 online services. If you’re concerned about your privacy, why would you
53 trust the images you’re processing to some unknown third party, who may be 53 trust the images you’re processing to some unknown third party, who may be
54 linked somehow to those who might want to retaliate against you.</p> 54 linked somehow to those who might want to retaliate against you?</p>
55 <p>I wrote this program because I wanted there to be a quick, easy way to 55 <p>I wrote this program because I wanted there to be a quick, easy way to
56 scrub images before they even left a photographer’s computer and made 56 scrub images before they even left a photographer’s computer and made
57 their way onto the Internet, and for that program to leave vital metadata 57 their way onto the Internet, and for that program to leave vital metadata
58 alone, so that the resulting images continue to display properly.</p> 58 alone, so that the resulting images continue to display properly.</p>
59 <h2>ExifWasher Washes More than Just Exif Metadata</h2> 59 <h2>JpegWasher Washes More than Just Exif Metadata</h2>
60 <p>Exif is the most common type of metadata, but image files commonly 60 <p>Jpeg is the most common type of metadata, but image files commonly
61 contain compromising XMP or IPTC data, particularly if they have been 61 contain compromising XMP or IPTC data, particularly if they have been
62 edited with a tool like Photoshop. ExifWasher will seamlessly deal with 62 edited with a tool like Photoshop. JpegWasher will seamlessly deal with
63 these kinds of metadata, too. It tries to do as thorough a job as possible 63 these kinds of metadata, too. It tries to do as thorough a job as possible
64 of scrubbing possibly compromising metadata from your images.</p> 64 of scrubbing possibly compromising metadata from your images.</p>
65 <h2>Using ExifWasher</h2> 65 <h2>Using JpegWasher</h2>
66 <p>Just double-click on the ExifWasher icon and a main window should open 66 <p>Just double-click on the JpegWasher icon and a main window should open
67 up. Either choose the File… Wash from the menu bar, or just drag image 67 up. Either choose the File… Wash from the menu bar, or just drag image
68 files onto the main ExifWasher image.</p> 68 files onto the main JpegWasher image.</p>
69 <p>When ExifWasher opens an image, it displays all the metadata it finds. 69 <p>When JpegWasher opens an image, it displays all the metadata it finds.
70 That metadata will be run through an internal whitelist, and any data 70 That metadata will be run through an internal whitelist, and any data
71 whose “key” is not found on the whitelist will be automatically selected 71 whose “key” is not found on the whitelist will be automatically selected
72 for deletion.</p> 72 for deletion.</p>
73 <p>If you disagree with ExifWasher’s decisions, you can check or uncheck the 73 <p>If you disagree with JpegWasher’s decisions, you can check or uncheck the
74 boxes next to the metadata in question. When you are satisfied with the 74 boxes next to the metadata in question. When you are satisfied with the
75 choice of metadata to be scrubbed, click “Wash” and all offending metadata 75 choice of metadata to be scrubbed, click “Wash” and all offending metadata
76 will be removed. A dialog will pop up showing the metadata remaining in 76 will be removed. A dialog will pop up showing the metadata remaining in
77 the new, washed file.</p> 77 the new, washed file.</p>
78 <h3>Important: Run ExifWasher Last!</h3> 78 <h3>Important: Run JpegWasher Last!</h3>
79 <p>Most image-editing tools insert telltale bits of metadata into the output 79 <p>Most image-editing tools insert telltale bits of metadata into the output
80 they create. Thus, only way you can create a file with the minimum amount 80 they create. Thus, only way you can create a file with the minimum amount
81 of metadata in it is to run ExifWasher as the final step in your image 81 of metadata in it is to run JpegWasher as the final step in your image
82 preparation.</p> 82 preparation.</p>
83 <h3>Washing Non-JPEG Images</h3>
84 <p>In short: it’s possible, but it is not recommended unless you <em>really</em>
85 know what you’re doing.</p>
86 <p>JpegWasher is called JpegWasher for a reason: it is geared to cleaning
87 metadata in <em>JPEG</em> files. Different types of images use metadata
88 differently; metadata that would be extraneous deadwood in a JPEG can be
89 critical to interpreting other image file formats correctly. JpegWasher’s
90 built-in whitelist is geared to what must be retained when washing JPEG
91 images, so <em>careless use of JpegWasher is likely to damage non-JPEG
92 files.</em> It is for this reason that JpegWasher will warn you if you
93 attempt to open and wash a non-JPEG file with it.</p>
83 <h2>Output Files</h2> 94 <h2>Output Files</h2>
84 <p>ExifWasher never modifies an existing image file. Instead, it creates a 95 <p>JpegWasher never modifies an existing image file. Instead, it creates a
85 new file of the same type but with “_washed” appended to its name. For 96 new file of the same type but with “_washed” appended to its name. For
86 example, processing <code>foo.jpg</code> will create <code>foo_washed.jpg</code>. 97 example, processing <code>foo.jpg</code> will create <code>foo_washed.jpg</code>.
87 By default, the new file will be created in the same directory as the file 98 By default, the new file will be created in the same directory as the file
88 being washed.</p> 99 being washed.</p>
89 <h2>ExifWasher is Configurable</h2> 100 <h2>JpegWasher is Configurable</h2>
90 <p>Both the whitelist and the destination directory for the washed files are 101 <p>Both the whitelist and the destination directory for the washed files are
91 user-configurable in the Preferences menu.</p> 102 user-configurable in the Preferences menu.</p>
92 <h3>Configuring the Whitelist</h3> 103 <h3>Configuring the Whitelist</h3>
93 <p>There are two kinds of whitelist entries: those that match an entire 104 <p>There are two kinds of whitelist entries: those that match an entire
94 metadata key, and those that match a key prefix. The latter end in an 105 metadata key, and those that match a key prefix. The latter end in an
95 asterisk. The whitelist is case-sensitive; i.e. the entry <code>exif.image.colormap</code> 106 asterisk. The whitelist is case-sensitive; i.e. the entry <code>exif.image.colormap</code>
96 <em>will not</em> match the <code>Exif.Image.ColorMap</code> key.</p> 107 <em>will not</em> match the <code>Exif.Image.ColorMap</code> key.</p>
97 <h2>That’s about It</h2> 108 <h2>That’s about It</h2>
98 <p>ExifWasher does not, and probably never will, do anything but remove 109 <p>JpegWasher does not, and probably never will, do anything but remove
99 extraneous metadata.</p> 110 extraneous metadata from JPEG files.</p>
100 <p>First, I have no desire to re-invent the wheel. There are already 111 <p>First, I have no desire to re-invent the wheel. There are already
101 excellent open-source tools like Gimp for image editing, and ExifTool and 112 excellent open-source tools like Gimp for image editing, and ExifTool and
102 Exiv2 for general-purpose metadata editing (in fact, ExifWasher is built 113 Exiv2 for general-purpose metadata editing (in fact, JpegWasher is built
103 on top of Exiv2). If you need the functionality of some other tool, 114 on top of Exiv2). If you need the functionality of some other tool,
104 download and use it!</p> 115 download and use it!</p>
105 <p>Second (and more importantly), I want ExifWasher to be simple, and 116 <p>Second (and more importantly), I want JpegWasher to be simple, and
106 therefore easy to learn and easy to use. The more challenging an 117 therefore easy to learn and easy to use. The more challenging an
107 information-security tool is to use, the less likely it is to be used 118 information-security tool is to use, the less likely it is to be used
108 frequently, and the more likely it is that compromising information gets 119 frequently, and the more likely it is that compromising information gets
109 disclosed.</p> 120 disclosed.</p>
110 </body> 121 </body>