h1. Installing and using ImageMagick

Jun 23, 2015

*On my local Linux Mint (Ubuntu)

@apt-get install imagemagick perlmagick@

If package not found, then first do:
@apt-get update@
and then try the install again.



h2. EXIF Data

http://stackoverflow.com/questions/1708417/how-can-i-extract-exif-data-using-perlmagick

http://hacktux.com/read/remove/exif


may want:
@apt-get install libimage-exiftool-perl@

@exiftool coreopsis.jpg@ will provide some info about the image.

but this might be better:
@apt-get install jhead@

@jhead coreopsis.jpg@


if want to remove exif data from an image:

q.
After ImageMagick is installed, you will have /usr/bin/mogrify available. The mogrify command can be used to strip Exif data from images.

mogrify -strip imagename.jpg

If you need to process a large number of files, use find and xargs:

find ./folder_of_images -name '*.jpg' | xargs mogrify -strip
q..




hr.

Perl usage
http://www.imagemagick.org/source/examples.pl


hr.


did not need to execute these commands. 

@apt-get install libconfig-yaml-perl@

@perl -MCPAN -e 'install Image::Magick'


hr.

install CPAN
reload CPAN


hr. 

check Ubuntu version

@lsb_release -a@


h2. orientation

fence.Value 0th Row 0th Column
1 top | left side  - [phone held in landscape pos with home button at right]
2 top | right side 
3 bottom | right side - (landscape photo that's upside-down. how taken?)
4 bottom | left side
5 left side | top
6 right side | top - [phone held in portrait pos with home button at bottom]
7 right side | bottom
8 left side | bottom
fence..


h2. Links

http://www.imagemagick.org/script/formats.php

DOC
http://www.imagemagick.org/script/perl-magick.php

http://www.imagemagick.org/script/examples.php

http://www.imagemagick.org/source/examples.pl

http://www.graphicsmagick.org/perl.html

http://sylvana.net/jpegcrop/exif_orientation.html



h2. Using Client-side Javascript to Resize an Image

http://stackoverflow.com/questions/5343915/javascript-library-similar-to-imagemagick-i-e-resize-images-and-pictures-whil

http://stackoverflow.com/questions/2303690/resizing-an-image-in-an-html5-canvas

http://davidwalsh.name/resize-image-canvas


hr.

http://stackoverflow.com/questions/6150289/how-to-convert-image-into-base64-string-using-javascript

http://jsfiddle.net/handtrix/YvQ5y/


hr.

https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement/toDataURL


hr.

http://www.sitepoint.com/html5-ajax-file-upload/

http://stackoverflow.com/questions/9395911/sending-a-file-as-multipart-through-xmlhttprequest

http://www.sitepoint.com/html5-javascript-file-upload-progress-bar/


hr.

https://dojotoolkit.org/documentation/tutorials/1.10/ajax/

https://dojotoolkit.org/documentation/tutorials/1.10/mobile/flickrview/part3/index.html

https://dojotoolkit.org/documentation/tutorials/1.10/jsonp/


http://dojotoolkit.org/reference-guide/1.10/dojo/json.html


hr.


http://stackoverflow.com/questions/21944247/sending-off-an-image-name-with-ajax


hr.

http://stackoverflow.com/questions/14383557/setting-canvas-todataurl-jpg-quality


q.
Edit: If you're using Fabric.js, another, very simple and human-readable way, is this:

canvas.toDataURL({
   format: 'jpeg',
   quality: 0.8
});
This also allows you to have other options, giving you the ability to crop the image, etc:

canvas.toDataURL({
    format: 'png',
    left: 300,
    top: 250,
    width: 200,
    height: 150
})
q..



hr.



http://code.flickr.net/2012/06/01/parsing-exif-client-side-using-javascript-2/



hr.


http://drbacchus.com/rotating-an-image-with-imagemagick-and-perl/

q.
... deg is the number of degrees through which you want to rotate it, with the default being 90 counterclockwise.
q..

the compass or rotation goes counterclockwise.



hr.

use Transpose or Transverse. for my usage, it will mainly be Transpose for photos taken in portrait mode on the phone which creates images with orientation = 6.


https://github.com/exif-js/exif-js


hr.


https://dojotoolkit.org/documentation/tutorials/1.8/ajax/

https://dojotoolkit.org/reference-guide/1.7/dojo/fromJson.html

https://dojotoolkit.org/reference-guide/1.7/dojo/toJson.html#dojo-tojson


hr.

http://stackoverflow.com/questions/11929099/html5-canvas-drawimage-ratio-bug-ios

https://github.com/protonet/plupload

https://github.com/moxiecode/plupload/issues/631

http://stackoverflow.com/questions/17081162/canvas-image-become-distorted-after-slice-and-shrink-in-ios-safari


hr.

http://nolanlawson.com/2015/06/30/safari-is-the-new-ie/