exif: image exif data on Ubuntu

We explored exiftool, a perl utility to view and edit image metadata, in an earlier article. However, it’s bulky and a lighter alternative sounds good. So we looked up exif, a very tiny utility that can read exif metadata and has limited editing capabilities.

nomacs: beautiful app to view, edit images

GPicView is the viewer of my choice when it comes to images. However, I came across a strong contender today – nomacs. While GPicView has no image editing features as such, nomacs in its light bulk come with some useful editing features. And the transition effects, aesthetics and slideshow modes are incredibly beautiful. One more plus point for nomacs – advanced settings are hidden for regular users as long as they are not turned on. Features at a glance:

• Supports the most common image formats including RAW
• Fast thumbnail preview
• Zoomable grid preview of thumbnails
• Display EXIF information
• Framless mode
• Change transparency of windows
• Display overview/histogram/file info
• File filtering/searching/sorting
• Improved anti-aliasing (cool for displaying highly textured images)
• Sllideshow
• Crop, resize, colour adjustment, rotate, create mosaic image
• Viewer Synchronization
• Supports Linux, Windows and Mac.

To install nomacs on Ubuntu:

$ sudo add-apt-repository ppa:nomacs/stable
$ sudo apt-get update
$ sudo apt-get install nomacs

Webpage: nomacs

How to remove file metadata

Metadata is data about data. There are several reasons you may want to remove metadata from files, e.g., to protect your location or even identity. Almost all modern cameras or mobile cameras store (exif) metadata embedded in the image which is unknowingly shared with others when you share images with them. The way to prevent it is to remove the metadata. We will explore some ways to remove the metadata on Linux. Each of the the solutions support many filetypes.

• exiftool
  Present in major distros by default. Runs from the cmdline and lightweight. Supports various file formats.
  Run the following to install on Ubuntu:

  $ sudo apt-get-install libimage-exiftool-perl

• Metadata Anonymisation Toolkit
  Supports various file types such as images, open doc formats, pdf, archive, audio and torrents. It comes with a GUI as well.
  Run the following to install on Ubuntu:

  $ sudo apt-get install mat

• Metadata Extraction Tool
  Supports images, document formats, audio-video, markup languages and Internet files. Download the latest binary, make it executable and run.

Read image EXIF data on Ubuntu

While many image viewers can show much of the EXIF data of an image, the one of my choice – fast and light GPicView can’t. Searching for an alternative, I found useful services which need you to upload your images. However, exiftool is already available in the repos and does the job well. As I found from synaptic, it is installed as part of the package libimage-exiftool-perl. It’s worth noting here that you can use the libimage-exiftool-perl utility to write exif data to images as well. exiftool shows all the EXIF information of an image in the terminal.

To install on Ubuntu, run:

$ sudo apt-get install libimage-exiftool-perl

Usage is very easy. A sample run on an image:

$ exiftool Android_logo.png

ExifTool Version Number	8.60
File Name	Android_logo.png
Directory	.
File Size	14 kB
File Modification Date/Time	2012:02:12 12:19:33+05:30
File Permissions	rw——-
File Type	PNG
MIME Type	image/png
Image Width	128
Image Height	128
Bit Depth	8
Color Type	RGB with Alpha
Compression	Deflate/Inflate
Filter	Adaptive
Interlace	Noninterlaced
Pixels Per Unit X	2835
Pixels Per Unit Y	2835
Pixel Units	Meters
Profile CMM Type	Lino
Profile Version	2.1.0
Profile Class	Display Device Profile
Color Space Data	RGB
Profile Connection Space	XYZ
Profile Date Time	1998:02:09 06:49:00
Profile File Signature	acsp
Primary Platform	Microsoft Corporation
CMM Flags	Not Embedded, Independent
Device Manufacturer	IEC
Device Model	sRGB
Device Attributes	Reflective, Glossy, Positive, Color
Rendering Intent	Media-Relative Colorimetric
Connection Space Illuminant	0.9642 1 0.82491
Profile Creator	HP
Profile ID	0
Profile Copyright	Copyright (c) 1998 Hewlett-Packard Company
Profile Description	sRGB IEC61966-2.1
Media White Point	0.95045 1 1.08905
Media Black Point	0 0 0
Red Matrix Column	0.43607 0.22249 0.01392
Green Matrix Column	0.38515 0.71687 0.09708
Blue Matrix Column	0.14307 0.06061 0.7141
Device Mfg Desc	IEC http://www.iec.ch
Device Model Desc	IEC 61966-2.1 Default RGB colour space – sRGB
Viewing Cond Desc	Reference Viewing Condition in IEC61966-2.1
Viewing Cond Illuminant	19.6445 20.3718 16.8089
Viewing Cond Surround	3.92889 4.07439 3.36179
Viewing Cond Illuminant Type	D50
Luminance	76.03647 80 87.12462
Measurement Observer	CIE 1931
Measurement Backing	0 0 0
Measurement Geometry	Unknown (0)
Measurement Flare	0.999%
Measurement Illuminant	D65
Technology	Cathode Ray Tube Display
Red Tone Reproduction Curve	(Binary data 2060 bytes, use -b option to extract)
Green Tone Reproduction Curve	(Binary data 2060 bytes, use -b option to extract)
Blue Tone Reproduction Curve	(Binary data 2060 bytes, use -b option to extract)
White Point X	0.31269
White Point Y	0.32899
Red X	0.63999
Red Y	0.33001
Green X	0.3
Green Y	0.6
Blue X	0.15
Blue Y	0.05999
Image Size	128×128