Posts Tagged ‘ImageMagick’

Merging pictures on Linux command shell with ImageMagick merge

Friday, May 17th, 2013

combining-multiple-jpg-png-pictures-imagemagick-magician-logo

It is generally useful to combine multiple pictures into single one. A example case, where merging pictures on Linux is necessary is if you previously used ImageMagick's convert command line tool to convert PDF file (pages) to JPEG / PNG pictures. Unfortunately convertion with convert(as far as I know is only capable of generating multiple picture files instead of one single one), thus you further need montage to merge pages in separate photos to one. In my case I had my Curriculum Vitae in PDF and I needed to have same PDF in single photo for my applications for online Job Employment Belarusian portal site rabota.tut.by.

montage is one of numerous ImageMagick package script (plugins).
On all major Linux distributions (Debian / Ubuntu, Fedora, CentOS, RHEL, SuSE) montage comes installed together with imagemagick deb / rpm package.

Whether you don't have montage on Debian / Ubuntu and deb derivatives install it via:

linux:~# apt-get install --yes imagemagick
....

On CentOS, Fedora, RHEL, SuSE to install montage:

[root@centos ~]# yum -y install imagemagick
....

To merge two JPEG Photos into single PNG format picture:
linux:~$ montage -geometry +2+2 Picture-1.jpeg Merged-picture.png

Combining more photos, lets say my 8 Pages photos output from previous PDF convert to pictures is done with:

linux:~$ montage -geometry +8+8 CV_Georgi_Georgiev_bg-0.png \ CV_Georgi_Georgiev_bg-1.png \ CV_Georgi_Georgiev_bg-2.png \ CV_Georgi_Georgiev_bg-3.png \ CV_Georgi_Georgiev_bg-4.png \ CV_Georgi_Georgiev_bg-5.png \ CV_Georgi_Georgiev_bg-6.png \ CV_Georgi_Georgiev_bg-7.png \ CV_Georgi_Georgiev_bg.png
montage has plenty of useful other options, to do various photo montages from command line. Other way to merge photos with montage is by using:

linux:~$ montage -mode concatenate -tile 1x input-pic*.jpg out.jpg

Merging photos is also possible by using directly convert.

Combining multiple photos into single JPEG or PNG with Imagick convert is done with:

linux:~$ convert -append input-pic-*.jpg combined-picture.jpg

Other example use of montage is located on ImageMagick's montage's script site here

How to digital watermark to a picture – Protect pic with copyright image or text with composite, convert and Phatch on GNU / Linux

Friday, March 23rd, 2012

Watermarking is a technique to identify a physical or non-physical object with its owner (creator). First watermarks in history originates from very ancient times.

There are two basic types of Watermark types:

I. Physical Watermarks (classical)

II. Digital Watermarks

Historically Classical Watermarks, were mostly important. As we tend to use more and more visible and we switch to use of more invisible stuff, nowdays the importance and use of digital watermarks is steadily raising.

You have most likely already seen pictures from websites which contain a copyright holder message stamp or website logo on it.
As you could imagine the picture watermark is placed in order to prevent pictures from being re-used in another internet space ,without the picture copyright holder explicit permission…

Watermarks have entered most if not all areas of our life, but we often don't recognize they're there / rarely think about them.
Few of the many "physical watermarks" we use daily are:
 

  • paper money watermark (to protect against anti money forgery)
  • bank debit / credit cards stamps near the card chip
  • postcards paper stamps

There are too many different kind of "physical watermarks" and since this is not the accent of this article, I will continue straight to explaiin a bit on Digital (picture) watermarks and how to watermark images with ImageMagick image editting command line suit.

Just like with physical watermarks, there are different kinds of digital watermarks. There are:
 

  • Picture (Images) digital watermarks
  • – Steganography

  • Video watermarks
  • Audio stream digital watermarks
  • Visual digital watermarks
  • – Visible area of text or picture over another text picture or video

  • Invisible digital watermarks
  • – digital information (files) metadata with watermark content etc.

The topic of watermarking is quite wide, so I will stop here and focus on the main idea of this article – to show how to place digital watermark on graphic image or collection of pictures.

The most straightway non-interactive way to do picture watermarking is with ImageMagick's composite command line tool. This little handy tool is capable of creating watermarks in single and multiple pictures.

If you prefer to have a simple text as a watermark, then you should use imagick's convert cmd.

1. Putting a watermark of picture in the right bottom corner

$ composite -gravity southeast -dissolve 100 \
watermark_picture.png image-to-watermark.png \
output-watermarked-image.png

Snoopy Writting pc freak watermark picture text watermark on the right bottom corner with composite

2. Placing watermark to picture in the bottom right corner

$ composite -gravity northeast -dissolve 80 \
watermark_picture.png image-to-watermark.png \
output-watermarked-image.png

Snoopy Writting pc freak picture text watermark on the right bottom corner with composite

3. Watermarking picture in the bottom left corner

$ composite -gravity southwest -dissolve 90 \
watermark_picture.png image-to-watermark.png \
output-watermarked-image.png

Snoopy writting watermarking picture on the bottom left corner imagemagick (composite)

4. Watermarking picture in the top left corner

$ composite -gravity northwest -dissolve 100 \
watermark_picture.png image-to-watermark.jpg \
output-watermarked-image.jpg

As you see from above example, composite even accept mixing up input / output between PNG and JPEG pictures 🙂

Output Watermarked Image picture on top left corner with pc-freak logo image Imagick composite

5. Put a watermark in the image center

$ composite -gravity center -dissolve 100 \
watermark_picture.png image-to-watermark.png \
output-watermarked-image.png

position watermark on the picture middle (center) composite output picture

6. Sealing image with custom text / Text Watermarking a picture

a) Writting text watermark to an image centered in "footer"

$ convert image-to-watermark.png -pointsize 20 \
-draw "gravity south fill black text 0,12 \
'hip0s Watermark'" output-watermarked-image.jpg

This will place a watermark in position 0,12, meaning the text will be added in the bottom center of the watermarked image.

Watermarking a picture sealing with custom text image imagick composite pic

-pointsize 20 defines the text font size. hip0s Watermark is the actual text that will be stamped.

b) Writting image watermark with font type customization (Arial Tahoma etc.):

To list all available fonts ready to be used by convert, type:

$ convert -list font
$ convert -list font |grep -i arial
Font: Arial-Black-Regular
family: Arial Black
glyphs: /usr/share/fonts/truetype/msttcorefonts/Arial_Black.ttf
Font: Arial-Bold
family: Arial
glyphs: /usr/share/fonts/truetype/msttcorefonts/Arial_Bold.ttf
Font: Arial-Bold-Italic
family: Arial
glyphs: /usr/share/fonts/truetype/msttcorefonts/arialbi.ttf
Font: Arial-Italic
family: Arial
glyphs: /usr/share/fonts/truetype/msttcorefonts/ariali.ttf
Font: Arial-Regular
family: Arial
glyphs: /usr/share/fonts/truetype/msttcorefonts/Arial.ttf

$ convert -list type
Bilevel
ColorSeparation
ColorSeparationMatte
Grayscale
GrayscaleMatte
Optimize
Palette
PaletteBilevelMatte
PaletteMatte
TrueColorMatte
TrueColor

On my system, I have 392 of fonts installed, to check the number of installed fonts ready for use by convert I used:

$ convert -list font|grep -i 'font:'|wc -l
392

To only check exact fonts names usable in convert:

$ convert -list font|grep -i 'font:'

To use the red marked Arial-Regular for font of the text picture timestamp issue;

$ convert watermark_picture.jpg -font Arial-Regular \
-pointsize 20 -draw "gravity south fill black text 0,12 'hip0s Watermark'" \
output-watermarked-image.jpg

Watermark and with Arial-Regular font image magick convert screenshot dog type writter

c) Using external font with convert to place image text watermark

Lets say you would like to use an external font (arhangai.ttf) not listed in convert -font list usable fonts:

$ convert image-to-watermark.png -pointsize 20 \
-font /usr/share/fonts/truetype/arhangai/arhangai.ttf \
-draw "gravity south fill black text 0,12 \
'hip0s Watermark'" output-watermarked-image_7.png

Talking about fonts, if you would like to add some external, nice free-fonts (ttf) files to your current logged in user, exec:

hipo@noah:~$ cd ~/fonts
hipo@noah:/fonts$ for i in \
$(lynx -dump http://www.webpagepublicity.com/free-fonts.html|grep -i .ttf|grep -i http|awk '{ print $2 }'); \
do wget -r -l2 -nd -Nc $i;
done

This will add 85 new nice looking fonts. Putting fonts in .fonts/ directory, are red while fonts are looked up by applications installed on respective the server or desktop GNU / Linux systems. Any font put there is ready to be used across all ImageMagick command line tools, as well as will be added across the list of possible fonts to use in GIMP and the rest of gui editors installed on the system.

According to the (watermark) texts font size passed to convert on some pictures the text written will exceed the picture dimensions and only partially some of the text intended as watermark will be visible.
If you encounter the exceed picture text problem, take few minutes and play with fonts sizes until you have a good font size to fit the approximate dimensions of the (expected minimum / maximum – horizontal and vertical) stamped picture dimensions.

For the sake of clarity, here is a list with arguments used in above, composite and convert examples.
 

  • composite — The ImageMagick command that combines two images.
  • -dissolve 80 — The number after the option determines the brightness of the watermark.  100 is full strength.
  • -gravity southeast — Determines the placement of watermark.
    Possible options are; north, west, south, east, northwest, northeast, southeast, southwest, center
  • watermark_picture.png — The watermark image is the first argument.
  • image-to-watermark.jpg — The second argument is the original image to be watermarked.
  • output-watermarked-image.jpg — The third argument is the new composite image to be created.
    N. B. !  If you don't specify a new file, be careful, the original file will be overwritten.

As ImageMagick is cross platform graphic editting suit – it runs on both *nix (Linux,BSD) and Windows. I have tested it on Linux, only but on FreeBSD and other BSDs it should work without any problem.
The composite and convert above examples should be easily rewritten to run on achieve watarmarking on MS Windows too.

7. Watermarking multiple pictures in a directory

To watermark multiple pictures within a directory use, a short bash loop in combination with either convert or composite could be used:

$ cd your-directory/
$ for i in *; do
convert $i -pointsize 20 -draw "gravity south fill black text 0,12 'hip0s Watermark'" output-watermarked-image.jpg
done

convert and composite also support wildcards like '*.JPG, *.PNG', but I'm not sure if this syntax can be used for mass picture marking?

8. Adding watermark and doing other various advanced Image Edit, Convert and Compose stuff with Phatch GUI program

Another program that is capable to put watermarks on pictures and besides that doing a number of routine graphic manipulation operations achievable with expert Image manipulation programs like GIMP / Inkscape is PHATCH = PHOTO & BATCH

Phatch is swiss army knife for doing web design or or graphics design on Linux.

Phatch is really great and easy to use program. Tt makes putting basic designer effects on pictures with no requirement for any design skills.
With Phatch you can become a designer for a day literally 😉

If you haven't used it yet, make sure you try it!
Below, are two screenshots of Phatch running on my Debian G* / Linux

Phatch Linux Debian Squeeze Screenshot

Phatch Linux Debian Squeeze Screenshot Watermark effect

Phatch is installable via apt on Debian and Ubuntu Linux. It has also a phatch-cli tools, which are a possible substitute to ImageMagick's composite / convert tools.

On deb based distros install Phatch with:

noah:~# apt-get --yes install phatch phatch-cli

In Phatch it is also possible, to create a combination of filters to be later applied to an image file or a group of image files all in a directory. The program capabilities are really outstanding, it is pure joy to work with it.

Using Phatch GUI interface is hard to comprehend in the beginning, I needed few minutes until I can get the idea how to use it. Anyhow once you know the basics, its very easy to use onwards.

Phatch currently can perform the following actions:
 

  • Auto Contrast – Maximize image contrast
  • Border – Crop or add border to all sides
  • Brightness – Adjust brightness from black to white
  • Canvas – Crop the image or enlarge canvas without resizing the image
  • Colorize – Colorize grayscale image
  • Common – Copies the most common pixel value
  • Contrast – Adjust from grey to black & white
  • Convert Mode – Convert the color mode of an image (grayscale, RGB, RGBA or CMYK)
  • Effect – Blur, Sharpen, Emboss, Smooth, ..
  • Equalize – Equalize the image histogram
  • Fit – Downsize and crop image with fixed ratio
  • Grayscale – Fade all colours to gray
  • Invert – Invert the colors of the image (negative)
  • Maximum – Copies the maximum pixel value
  • Median – Copies the median pixel value
  • Minimum – Copies the minimum pixel value
  • Offset – Offset by distance and wrap around
  • Posterize – Reduce the number of bits of colour channel
  • Rank – Copies the rank'th pixel value
  • Rotate – Rotate with random angle
  • Round – Round or crossed corners with variable radius and corners
  • Saturation – Adjust saturation from grayscale to high
  • Save – Save an image with variable compression in different types
  • Scale – Scale an image with different resample filters.
  • Shadow – Drop a blurred shadow under a photo with variable position, blur and color
  • Solarize – Invert all pixel values above threshold
  • Text – Write text at a given position
  • Transpose – Flip or rotate an image by 90 degrees
  • Watermark – Apply a watermark image with variable placement (offset, scaling, tiling) and opacity

Most of the function / effects Phatch in the up list works fine as I tested them to get to know the program.
The only effect that didn't worked for me is Blender effect.
Trying to apply the Blending effect I got error:

Can not apply action Blender:
'dict' object has no attribute 'rfind'

dict object has not attribiture rfind error screenshot my linux

Its really a pity blender filter don't work. I've seen on Phatch's website some pictures showing the blender effect in action and it looks really awesome.

In attempt to work around the err, I tried downloading Phatch's latest release and running it with python interpreter but it didn't work out …
I tried also to install some packages to the system that somehow seemed to be related to blenderversatile 3D modeller/renderer program but this worked neither.
I suspect Phatch blender effect is not working on Ubuntu too as I've red complains in some Ubuntu forums.
If someone succeeding making blend effect work please let me know how?

Interesting feature of Phatch is the program support for applying its predefined filters using a cli interface.
The syntax for phatch cli, should be something like:

phatch -console action_list.phatch

Where action_list.phatch is a Phatch predefined filter. Anyways I didn't manage to figure out how to use the program CLI. I'll be glad to hear if someone succeeded in using the program console, if so please share with me how?

9. Adding Watermark to pictures with GIMP

To add a watermark text or picture in GIMP, there are plenty of ways but is more time consuming by both Phatch or convert, composite..
There is a script in gimp plugin registry site – watermark.scm which adds watermarking capability to GIMP

On my system this script was installed with the deb package gimp-data-extras. To apply the plugin on a pic, I used GIMP menus:

Filters -> Eg -> Copyright Placer

GIMP Copyright Holder plugin Watermark Screenshot

If someone knows about better or quicker ways to do watermarking, please share 🙂

Convert single PDF pages to multiple SVG files on Debian Linux with pdf2svg

Sunday, February 26th, 2012

In my last article, I've explained How to create PNG, JPG, GIF pictures from one single PDF document
Convertion of PDF to images is useful, however as PNG and JPEG graphic formats are raster graphics the image quality gets crappy if the picture is zoomed to lets say 300%.
This means convertion to PNG / GIF etc. is not a good practice especially if image quality is targetted.

I myself am not a quality freak but it was interesting to find out if it is possible to convert the PDF pages to SVG (Scalable Vector Graphics) graphics format.

Converting PDF to SVG is very easy as for GNU / Linux there is a command line tool called pdf2svg
pdf2svg's official page is here

The traditional source way compile and install is described on the homepage. For Debian users pdf2svg has already existing a deb package.

To install pdf2svg on Debian use:

debian:~# apt-get install --yes pdf2svg
...

Once installed usage of pdf2svg to convert PDF to multiple SVG files is analogous to imagemagick's convert .
To convert the 44 pages Projects.pdf to multiple SVG pages – (each PDF page to a separate SVG file) issue:

debian:~/project-pdf-to-images$ for i in $(seq 1 44); do \
pdf2svg Projects.pdf Projects-$i.SVG $i; \
done

This little loop tells each page number from the 44 PDF document to be stored in separate SVG vector graphics file:

debian:~/project-pdf-to-images$ ls -1 *.svg|wc -l
44

For BSD users and in particular FreeBSD ones png2svg has a bsd port in:

/usr/ports/graphics/pdf2svg

Installing on BSD is possible directly via the port and convertion of PDF to SVG on FreeBSD, should be working in the same manner. The only requirement is that bash shell is used for the above little bash loop, as by default FreeBSD runs the csh. 
On FreeBSD launch /usr/local/bin/bash, before following the Linux instructions if you're not already in bash.

Now the output SVG files are perfect for editting with Inkscape or Scribus and the picture quality is way superior to old rasterized (JPEG, PNG) images

How to take multiple screenshots with scrot and ImageMagick import commands in terminal on GNU / Linux and FreeBSD

Friday, January 13th, 2012

scrot and import are two commands, which can be used to take screenshot in terminal on Linux and FreeBSD:

To use scrot cmd to take screenshots on Ubuntu and Debian the scrot package has to be installed:

noah:~# apt-get install scrot
...

scrot should also be available on most other Linux distributions in the main repositories, I'll be glad to hear if someone has used it on Fedora, SUSE etc.

On FreeBSD, there is a port called scrot , to install on FreeBSD:

freebsd# cd /usr/ports/graphics/scrot
freebsd# make install clean
...

Scrot has plenty of nice arguments one can use to make a screenshot. Maybe the most handy one in my view is after a preliminary set delay before screenshot is taken.

To take screenshot with it after lets say 5 seconds delay before the screenshot:

hipo@noah:~/Desktop$ scrot -t 20 -d 5

Screenshot scrot my debian Linux gnome-termina

To put an year, month and day and year followed by screen resolution with scrot :

hipo@noah:~$ scrot '%Y-%m-%d_$wx$h.png'

Another way to take a screenshot of screen with command is by using ImageMagick'simport image manipulation package.
To take screenshot of the current screen via terminal using import , type in xterm, gnome-termina or Gnome's Run Application (ALT+F2)

hipo@noah:~$ import -window root ScreenShot.png

To make import command to save the taken screenshot in a format (minute:hour:day:month:year)i :

hipo@noah:~$ import -window root $screenshot_dir/screenshot-$(date +%M_%k_%d_%m_%Y|sed -e 's/^ *//').png

Taking a delayed screenshot is also possible via The GIMP via menus File -> Create -> Screenshot

GIMP Screenshot 15 seconds delay GIMP window screenshot

Now here is an interesting question, what if I would like to take periodic screenshots of what I do on my Desktop to take random movie scenes from a movie I watch with totem or vlc??

This task is quite easily achiavable with a little bash shell script, I wrote:

screenshot_dir='Screenshots';
seconds='60';
if [ ! -d "$screenshot_dir" ]; then
mkdir $screenshot_dir;
fi
while [ 1 ]; do
sleep $seconds;
(import -window root $screenshot_dir/screenshot-$(date +%M_%k_%d_%m_%Y|sed -e 's/^ *//').png) &
done

This script will take screenshot automatically to Screenshots/ directory every (1 min – 60 seconds)
You can also my downloads take_screenshot_every_60_secs_import.sh here

To use take_screenshot_every_60_secs_import.sh just issue the script inside xterm or gnome-terminal, after that simply use your computer as you normally would.
The script will take snapshots every minute and store all taken screenshots in Screenshots dir.

If you prefer to use scrot to take automatically the screenshots every lets say 5 minutes, you can use a script like:

screenshot_dir='Screenshots';
# 300 secs (5 mins)seconds='300';
if [ ! -d "$screenshot_dir" ]; then
mkdir $screenshot_dir;
fi
while [ 1 ]; do
sleep $seconds;
(scrot $screenshot_dir/'%Y-%m-%d_$wx$h.png') &
done

You can fetch take_screenshot_every_60_secs_scrot.sh here

The script using scrot is better in terms of efficiency, the system load scrot will put on your machine will be less.
Using some of this scripts will be handy if you need screenshots to Movies, Programs and favourite Free Software games.
Hope this is educative to someone 😉

How to take a screenshot of a game or Full Screen running program inside GNOME or KDE desktop environment on GNU / Linux and FreeBSD

Thursday, December 15th, 2011

Image Magick logo take screenshot of fullscreen running program with import on Linux / FreeBSD

I’m writting some game reviews and movie reviews, every now and then and therefore being able to capture a fullscreen running program like let’s say mplayer or vlc or some full screen running game is something I really need.

The usual PrtScr button which normally works to prepare screenshots in GNOME or KDE, however is not working if the root window handler is being passed to a different program than the Window Manager and pressing it while inside of many older programs or applicationsdoes not produce a print screen of the current screen.

Anyways I found a hack to this using the good old ImageMagickimport command line screenshotting program.

To take a screenshot of a certain program run from gnome-terminal or konsole using import cmd its possible to use a quick one liner which will take a snapshot of the root Window the started program will use.

Let’s say you want to make a screenshot of the entry screen of the FreeDOOM (DooM 3d shooter classical game arcade free Software Alternative).

Launch gnome-terminal or konsole , xterm , depending on the GUI environment you use and issue the commands:

debian:~$ ( sleep 15; import -window root my_desired_screenshot_name.png ) &
debian:~$ freedoom

The first command will launch import after a sleep of 15 secs and therefore will screenshot the active window which will be at focus after 15 seconds, where the & sign will background it and the second one will launch FreeDooM . You will have to wait for a certain secs and switch to the exact screen you will want to screenshot.
If you want to screenshot some game scene that will appear in 20 minutes change above sleep 15 cmd to be to something like sleep 180
That method can be used for screenshotting any other program running on fullscreen, the method is a bit inflexible as you will have to adjust a timing but it works fine 😉

Create PDF file from (png, jpg, gif ) images / pictures in Linux

Tuesday, September 14th, 2010

I’ve recently received a number of images in JPEG format as a feedback on a project plan that was constructed by a team I’m participating at the university where I study.

Somebody from my project group has scanned or taken snapshots of each of the hard copy paper feedback and has sent it to my mail.

I’ve received 13 images so I had to open them one by one to get each of the Project Plan to read the feedback on the page this was really unhandy, so I decided to give it a try on how to generate a common PDF file from all my picture files.

Thanksfully it happened to be very easy and trivial using the good old Image Magick

In order to complete the task of generating one PDF from a number of pictures all I did was.1. Switch to the directory where I have saved all my jpeg images

debian:~# cd /home/hipo/Desktop/my_images_directory/

2. Use the convert binary part of imagemagick package to generate the actual PDF file from the group of images

debian:~# convert *.jpg outputpdffile.pdf

If the images are numbered and contain many scanned pages of course you can always pass by all the images to the /usr/bin/convert binary, like for instance:

debian:~# convert 1.jpg 2.jpg 3.jpg 4.jpg 5.jpg outputpdffile.pdf
Even though in my case I had to convert to PDF from multiple JPEG (JPG) pictures, convertion with convert is not restricted to convert only from JPEG, but you can also convert to PDF by using other graphical file formats.

For instance to convert multiple PNG pictures to a single PDF file the command will be absolutely the same except you change the file extension of the graphic files e.g.:

debian:~# convert 1.PNG 2.PNG 3.PNG 4.PNG 5.PNG OUTPUT-PDF-FILE.PDF

I was quite happy eventually to know Linux is so flexible and such a trivial things are able to be completed in such an easy way.