Use the -sampling-factor option to set the sampling factor to be used by JPEG, MPEG, and YUV encoders for down-sampling the chroma channels. Use the -quality option to set the compression level to be used by JPEG, PNG, MIFF, and MPEG encoders. You may choose another type of compression using the -compress flag and specify None, BZip, Fax, Group4, JPEG, JPEG2000, Lossless, LZW, RLE or Zip. It will use a compression which is relevant to the type of file you are using (jpegs are compressed differently than pngs). Use it to convert between image formatsĪs well as resize an image, blur, crop, despeckle, dither, draw on,įor more information about the convert command, point your browser toįile:///usr/share/doc/imagemagick-6-common/html/www/convert.html (onĭebian system you may install the imagemagick-6 package) or 1 will ensure highest compression but lowest image quality, and 100 will ensure highest image quality. The convert-im6.q16 program is a member of the ImageMagick- For JPG (JPEG) images, the quality ranges from 1 to 100. There is another way to create thumbnails that works quite well if you want to crop the image rather than using the entire image.If you don't mind using SVG as an intermediary format, then inkscape may be useful.īut you're probably looking for ImageMagick's convert.įrom the man page: convert-im6.q16(1) General Commands Manual convert-im6.q16(1)Ĭonvert - convert between image formats as well as resize an image,īlur, crop, despeckle, dither, draw on, flip, join, re-sample, andĬonvert-im6.q16 input-file output-file Read about this at Imagick::thumbnailImage NOTE: The $thumbnail->thumbnailImage(100,null) keeps the aspect ration by setting the second parameter to null. I only used so many to demonstrate where the images are coming from and where they are going. This article introduces some basic concepts and examples to get started. The ImageMagick library has an overwhelming amount of functionality. Now, obviously you don't have to do so much with the variables and the file location. The magick package: Advanced Image-Processing in R The magickpackage provide a modern and simple toolkit for image processing in R. With ImageMagick you can create images dynamically, making it suitable for Web applications. $thumbnail -> writeImage ( $thumb_destination ) Imagemagick is a robust collection of tools and libraries offered under a usage license to read, write, and manipulate an image in many image formats (over 87 major formats) including popular formats like TIFF, JPEG, PNG, PDF, PhotoCD, and GIF. It can display an image on any workstation display running an X server. $thumbnail -> thumbnailImage ( 100, null ) Description ImageMagick provides a suite of command-line utilities for creating, converting, editing, and displaying images: display is a machine architecture independent image processing and display facility. $thumbnail -> setImageCompressionQuality ( 40 ) $thumbnail -> setImageCompression ( $compression_type ) This will use the following functions in reference: This example shows how to set the compression type, set the compression quality, create a thumbnail and remove unnecessary data in order to reduce file size. Getting Started Introduction A simple tutorial Language Reference Basic syntax Types Variables Constants Expressions Operators Control Structures Functions Classes and Objects Namespaces Enumerations Errors Exceptions Fibers Generators Attributes References Explained Predefined Variables Predefined Exceptions Predefined Interfaces and Classes Predefined Attributes Context options and parameters Supported Protocols and Wrappers Security Introduction General considerations Installed as CGI binary Installed as an Apache module Session Security Filesystem Security Database Security Error Reporting User Submitted Data Hiding PHP Keeping Current Features HTTP authentication with PHP Cookies Sessions Dealing with XForms Handling file uploads Using remote files Connection handling Persistent Database Connections Command line usage Garbage Collection DTrace Dynamic Tracing Function Reference Affecting PHP's Behaviour Audio Formats Manipulation Authentication Services Command Line Specific Extensions Compression and Archive Extensions Cryptography Extensions Database Extensions Date and Time Related Extensions File System Related Extensions Human Language and Character Encoding Support Image Processing and Generation Mail Related Extensions Mathematical Extensions Non-Text MIME Output Process Control Extensions Other Basic Extensions Other Services Search Engine Extensions Server Specific Extensions Session Extensions Text Processing Variable and Type Related Extensions Web Services Windows Only Extensions XML Manipulation GUI Extensions Keyboard Shortcuts ? This help j Next menu item k Previous menu item g p Previous man page g n Next man page G Scroll to bottom g g Scroll to top g h Goto homepage g s Goto search
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