File:Printer Steganography.jpg
Original file (1,248 × 1,248 pixels, file size: 175 KB, MIME type: image/jpeg)
Captions
Summary
[edit]DescriptionPrinter Steganography.jpg |
Yellow dots printed by a color laser printer to identify the printer. The dots encode printing date, type of printer and printer ID. See: https://www.eff.org/Privacy/printers/index.php The ruler is in centimeters. The image was taken with a blue led illuminating the page, so that black and yellow appear dark. Then the levels were adjusted to bring out the dots. Yellow doesn't photograph well in RGB. |
Source | Own work |
Author | Hustvedt |
Licensing
[edit]Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License.http://www.gnu.org/copyleft/fdl.htmlGFDLGNU Free Documentation Licensetruetrue |
- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
- share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.
File history
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Date/Time | Thumbnail | Dimensions | User | Comment | |
---|---|---|---|---|---|
current | 05:41, 10 March 2008 | 1,248 × 1,248 (175 KB) | Hustvedt (talk | contribs) | Crop, levels, etc. to make it much more clear. Old version has a blue to white transition, but isn't that useful. | |
05:35, 10 March 2008 | 2,997 × 1,833 (803 KB) | Hustvedt (talk | contribs) | {{Information |Description=Yellow dots printed by a color laser printer to identify the printer. The dots encode printing date, type of printer and printer ID. See: http://www.eff.org/Privacy/printers/index.php The ruler is in centimeters. |Source=self-ma |
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File usage on Commons
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Metadata
This file contains additional information such as Exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it. If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of the original file. The timestamp is only as accurate as the clock in the camera, and it may be completely wrong.
Camera manufacturer | PENTAX Corporation |
---|---|
Camera model | PENTAX K100D |
Exposure time | 1/6 sec (0.16666666666667) |
F-number | f/6.7 |
ISO speed rating | 200 |
Date and time of data generation | 23:30, 9 March 2008 |
Lens focal length | 100 mm |
Orientation | Normal |
Horizontal resolution | 72 dpi |
Vertical resolution | 72 dpi |
Software used | K100D Ver 1.02 |
File change date and time | 23:30, 9 March 2008 |
Y and C positioning | Co-sited |
Exposure Program | Aperture priority |
Exif version | 2.21 |
Date and time of digitizing | 23:30, 9 March 2008 |
Meaning of each component |
|
APEX exposure bias | 0 |
Metering mode | Center weighted average |
Flash | Flash did not fire, compulsory flash suppression |
Supported Flashpix version | 1 |
Color space | sRGB |
Sensing method | One-chip color area sensor |
File source | Digital still camera |
Scene type | A directly photographed image |
Custom image processing | Normal process |
Exposure mode | Auto exposure |
White balance | Manual white balance |
Focal length in 35 mm film | 150 mm |
Scene capture type | Standard |
Contrast | Normal |
Saturation | Normal |
Sharpness | Normal |
Subject distance range | Macro |