If you are using a `convert` command line you can execute it with these parameters:


    convert  source.pdf[0]  output.jpeg


Note that the page count of ImageMagick is 0-based. So `[0]` means &#39;page 1&#39;. To select, say the 4th page, you&#39;d have to use `[3]`.

This syntax does not only work for PDF input. It also works with other multi-page or mult-frame formats, such as multi-page TIFF or animated multi-frame GIFs and PNGs.




Don&#39;t use ImageMagick, use Ghostscript. ImageMagick calls Ghostscript to do the work anyway...

    gs -sDEVICE=jpeg -sOutputFile=&lt;output-filename&gt; -dLastPage=1 &lt;input filename&gt;

You can also change the device to `jpegcmyk` (for CMYK output) or `jpeggray` for gray output, you can change the resolution using `-r`, use `-dFirstPage` and `-dLastPage` to extract a continuous range of pages, etc.


To further the answer by @KenS, Here are a more few details, particularly for Windows users.

You can download GhostScript for Windows here: http://www.ghostscript.com/download/gsdnld.html. The default installation path for the executable is &quot;C:\Program Files\gs\gs910\bin\gswin64c.exe&quot;.

The command-line arguments listed above are correct in Windows too, but here are a few more that I found useful:

    gswin64c.exe -dNOPAUSE -dBATCH -r96 -sDEVICE=jpeg -sOutputFile=&quot;&lt;out-file.jpg&gt;&quot;
                 -dFirstPage=1 -dLastPage=1 &quot;&lt;input-file.pdf&gt;&quot;

I also created a batch file that wraps this up nicely and posted it to my GitHub account. It makes it a lot easier to create thumbnails for multiple .pdf files too. Check it out at [pdf2jpg.bat](https://github.com/kodybrown/dos/blob/master/pdf2jpg.bat).

I have a situation where I&#39;m trying to use grunt to lint a codebase, excluding specific folders.

grunt uses minimatch (similar to bsdglob) under the hood to match files, but I can&#39;t seem to figure out how to do a .gitignore style exclude of a folder.

I&#39;d like to ingest this:

`ignoreme`

and match these:

    /folder/path/here/to/something/ok.js
    /another/folder/path.js
    /test.js

but not match these:

    /folder/ignoreme/something.js
    /folder/path/here/to/ignoreme/metoo/file.js

This will match everything, including ignoreme:

    /**/*.js

So I figured I could do something like:

    /**/!(ignoreme)/**/*.js

but that matches files in the ignoreme folder.

I&#39;m used to regexes, but can&#39;t seem to figure out how to repeat a pattern or something here - I also tried stuff like:

    /(!(ignoreme)|*)*/*.js

hoping the container would repeat, but that doesn&#39;t work, it just fails to match everything.

Any way to either pass a regex to grunt file paths, or make this work for me?

Update:
===

Here&#39;s how I&#39;m currently dealing with this issue:

    var pattern = /\/ignoreme\//
    var files = grunt.file.expandFiles(arrayOfFilesPassedToMinimatch).filter(function(f){
      return !pattern.test(f)
    })

I&#39;d still be interested if folder excludes are possible in minimatch.

grunt (minimatch/glob) folder exclusion

I want to center the text *vertically* inside a big `UITextView` that fills the whole screen - so that when there&#39;s little of text, say a couple of words, it is centered by height. 
It&#39;s not a question about centering the text (a property that can be found in IB) but about putting the text *vertically* right in the middle of `UITextView` *if* the text is short, so there are no blank areas in the `UITextView`.
Can this be done? Thanks in advance!

Center text vertically in a UITextView

How do I execute ImageMagick&#39;s `convert` if I want a JPEG *from the first page only* of a multi-page PDF?


How to execute ImageMagick to convert only the first page of the multipage PDF to JPEG?

<p>How do I execute ImageMagick's <code>convert</code> if I want a JPEG <em>from the first page only</em> of a multi-page PDF?</p>


I am trying to build a PDF file out of a binary stream which I receive as a response from an Ajax request.

Via `XmlHttpRequest` I receive the following data:


    %PDF-1.4....
    .....
    ....hole data representing the file
    ....
    %% EOF


What I tried so far was to embed my data via `data:uri`. Now, there&#39;s nothing wrong with it and it works fine. Unfortunately, it does not work in IE9 and Firefox. A possible reason may be that FF and IE9 have their problems with this usage of the `data-uri`.

Now, I&#39;m looking for any solution that works for all browsers. Here&#39;s my code:

    // responseText encoding 
    pdfText = $.base64.decode($.trim(pdfText));

    // Now pdfText contains %PDF-1.4 ...... data...... %%EOF

    var winlogicalname = &quot;detailPDF&quot;;
    var winparams = &#39;dependent=yes,locationbar=no,scrollbars=yes,menubar=yes,&#39;+
				&#39;resizable,screenX=50,screenY=50,width=850,height=1050&#39;;

    var htmlText = &#39;&lt;embed width=100% height=100%&#39;
	                     + &#39; type=&quot;application/pdf&quot;&#39;
	                     + &#39; src=&quot;data:application/pdf,&#39;
	                     + escape(pdfText)
	                     + &#39;&quot;&gt;&lt;/embed&gt;&#39;; 
	                
	                // Open PDF in new browser window
	                var detailWindow = window.open (&quot;&quot;, winlogicalname, winparams);
	                detailWindow.document.write(htmlText);
	                detailWindow.document.close();


As I have said, it works fine with Opera and Chrome (Safari hasn&#39;t been tested). Using IE or FF will bring up a blank new window.

Is there any solution like building a PDF file on a file system
in order to let the user download it? I need the solution that works in all browsers, at least in IE, FF, Opera, Chrome and Safari.

I have no permission to edit the web-service implementation. So it had to be a solution at client-side. Any ideas?

How to build PDF file from binary string returned from a web-service using javascript

I cannot get `z-index` working on a `iframe` that contains a pdf file with IE8. It works with Google Chrome.

Example ([JSFiddle](http://jsfiddle.net/5J6zL/9/)):

**HTML**

    &lt;div id=&quot;div-text&quot;&gt;
          &lt;div id=&quot;shouldBeOnTop&quot;&gt;my text that should be on top&lt;/div&gt;
    &lt;/div&gt;
    &lt;div id=&quot;div-frame&quot;&gt;
        &lt;iframe src=&quot;http://legallo1.free.fr/french/CV_JLG.pdf&quot; width=&quot;200&quot; height=&quot;200&quot;/&gt;
    &lt;/div&gt;

**CSS**

&lt;!-- language: lang-css --&gt;

    #div-text{
        position:relative;
        left:210px;
        top:20px
    }
    
    #shouldBeOnTop{
        position:relative;
        right:60px;
        background-color:red;
        width:100px;
        z-index:2;
    }
    
    #div-frame{
        position:relative;
         z-index:1;
    }

z-index does not work in Internet Explorer with pdf in iframe

&gt; Duplicate headers received from server
&gt;
&gt; The response from the server contained duplicate headers. This problem is generally the result of a misconfigured website or proxy. Only the website or proxy administrator can fix this issue.
&gt;
&gt; Error 349 (net::ERR_RESPONSE_HEADERS_MULTIPLE_CONTENT_DISPOSITION): Multiple distinct Content-Disposition headers received. This is disallowed to protect against HTTP response splitting attacks.

 I found this error while exporting to pdf in chrome.

    Response.Buffer = false;
    Response.ClearHeaders();
    string ext = objProp.PACKAGEFILENAME.Substring(objProp.PACKAGEFILENAME.LastIndexOf(&quot;.&quot;));
    string ext1 = ext.Substring(1);
    Response.ContentType = ext1;
    Response.AddHeader(&quot;Content-Disposition&quot;, &quot;target;_blank,attachment; filename=&quot; + objProp.PACKAGEFILENAME);
    const int ChunkSize = 1024;
    byte[] binary = objProp.PACKAGEDOCUMENT;
    System.IO.MemoryStream ms = new System.IO.MemoryStream(binary);
    int SizeToWrite = ChunkSize;

    for (int i = 0; i &lt; binary.GetUpperBound(0) - 1; i = i + ChunkSize)
    {
        if (!Response.IsClientConnected) return;
        if (i + ChunkSize &gt;= binary.Length) SizeToWrite = binary.Length - i;
        byte[] chunk = new byte[SizeToWrite];
        ms.Read(chunk, 0, SizeToWrite);
        Response.BinaryWrite(chunk);
        Response.Flush();
    }
    Response.Close();

How to fix this?

Duplicate headers received from server

If I&#39;m not mistaken, Google Docs offers the means to display a PDF that is stored on the same server as the web page via an `&lt;iframe&gt;`, but I need to know how I can do this in a cross-browser compliant way.

How to embed a PDF viewer in a page?

I want to code an application that can read and decode a pdf document; now where I&#39;m supposed to get the specs for this fileformat ? The PDF format is standardized from the ISO group but it&#39;s not clear to me where is the most reliable source for getting this kind of informations.

what is a good source to start with this file format ?

PDF specifications for coders: Adobe or ISO?

I have the following GIF image file:

![original gif image][1]

  [1]: http://i.stack.imgur.com/Cl6R2.gif

I want to extract its frames (using PGM output format) using this imagemagick command:

    convert brocoli.gif out%05d.pgm

But each frame has a different size.

How can I extract its frames while preserving the original gif file size?

How to extract frames from a GIF file preserving frame dimensions

How do I convert a RGB image (3 channels) to a grayscale one, using the (r+g+b)/3 method?
I look through an examples page: http://www.imagemagick.org/Usage/color_mods/#grayscale
but the desired method:

    convert test.png -fx &#39;(r+g+b)/3&#39; gray_fx_average.png

gave me a wrong result - the resulted image has still 3 channels.

You can check this by running a command: `identify -format &quot;%[colorspace]   &lt;== %f\n&quot; *.png`.


Convert RGB to Grayscale in ImageMagick command-line

I&#39;m on Mountain Lion and installed ImageMagick using Homebrew (minimagick is also in my Gemfile but I don&#39;t think that&#39;s relevant). [SimpleCaptcha](https://github.com/galetahub/simple-captcha) uses it in a Rails app to create CAPTCHAs. 

However, the image isn&#39;t created cause of this error:

    Error while running convert: convert: unable to read font `/usr/local/share/ghostscript/fonts/n019003l.pfb&#39; @ error/annotate.c/RenderFreetype/1123.
    convert: Postscript delegate failed `/var/folders/gd/n7rzfhkd5jd0ws8jnzsz34hr0000gn/T/magick-vzHHz4ZP&#39;: No such file or directory @ error/ps.c/ReadPSImage/830.
    convert: no images defined `/var/folders/gd/n7rzfhkd5jd0ws8jnzsz34hr0000gn/T/simple_captcha20121218-64930-1thtfpf.jpg&#39; @ error/convert.c/ConvertImageCommand/3032.

Any ideas?



ImageMagick: Error while running convert: convert: unable to read font

I have seen other people with the same issue of [installing RMagick on Mountain Lion](https://stackoverflow.com/questions/11676844/issue-with-installing-imagemagick-and-rmagick-on-mountain-lion) However none of the suggested solutions have allowed me to successfully install rmagick. 

Here is the error message I am getting:

    Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.
    checking for Ruby version &gt;= 1.8.5... yes
    checking for /usr/local/bin/gcc-4.2... yes
    checking for Magick-config... yes
    checking for ImageMagick version &gt;= 6.4.9... yes
    checking for HDRI disabled version of ImageMagick... yes
    checking for stdint.h... yes
    checking for sys/types.h... yes
    checking for wand/MagickWand.h... yes
    checking for InitializeMagick() in -lMagickCore... no
    checking for InitializeMagick() in -lMagick... no
    checking for InitializeMagick() in -lMagick++... no
    Can&#39;t install RMagick 2.13.1. Can&#39;t find the ImageMagick library or one of the dependent    libraries. Check the mkmf.log file for more detailed information.

    *** extconf.rb failed ***
    Could not create Makefile due to some reason, probably lack of
    necessary libraries and/or headers.  Check the mkmf.log file for more
    details.  You may need configuration options.

Things I have done:

    Installed XCode
    Installed the command line tools
    Installed XQuartz
    Installed homebrew with imagemagick library
    Installed most recent version of RVM
    Symlinked GCC
    Uninstalled and reinstalled both RVM and imagemagick


Any ideas why I still can&#39;t download rmagick?

Error installing Rmagick on Mountain Lion

There&#39;s plenty of information about cropping images, but attempting to crop (or trim) animations produces strange results. Sometimes they flicker, or come with extra frames, or some frames crop correctly and others become offset. How do I prevent all this from happening?

How do I crop an animated gif using ImageMagick?

I&#39;m building an app that uses a lot of images, so it&#39;s getting pretty big. I got more than 15mb in PNG images, and if I convert those images to JPG I would get 5MB or less! So, why should I use PNG instead of JPG?

I know that PNGs are preferred, but what would I lose with JPG?

EDIT: Thank you everybody!

Just a note: Since I got my answer and turns out that I will need to use PNG in most files, I found out that website http://tinypng.org/ , and that&#39;s helping me a lot. My 15mb of images are now 7mb. So, if anyone is in the same situation that I am, I hope that it helps!

Why should I use PNG and not JPG?

As a general rule of thumb when is it appropriate to make a gif interlaced, a png interlaced and a jpeg progressive?

Especially when publishing the image on the web.

When to interlace an image?

I am taking a jpg image and using numpy&#39;s fft2 to create/save a new image. However it throws this error 

    &quot;IOError: cannot write mode F as JPEG&quot; 

Is there an issue with CMYK and JPEG files in PIL???

    p = Image.open(&#39;kibera.jpg&#39;)
    bw_p = p.convert(&#39;L&#39;)
    array_p = numpy.asarray(bw_p)
    fft_p = abs(numpy.fft.rfft2(array_p))
    new_p = Image.fromarray(fft_p)
    new_p.save(&#39;kibera0.jpg&#39;)
    new_p.histogram()


PIL cannot write mode F to jpeg

I&#39;m using [`javax.imageio.ImageIO`][2] to save a `BufferedImage` as a jpeg file. 
In particular, I created the following Java function:

    public static void getScreenShot(BufferedImage capture, Path folder, String filename) {
            try {
                ImageIO.write(capture, &quot;jpeg&quot;, new File(folder.toString()+&quot;/&quot;+filename+&quot;.jpg&quot;));
            } catch (AWTException | IOException ex) {
                Logger.getLogger(ScreenShotMaker.class.getName()).log(Level.SEVERE, null, ex);
            }
    }

Likewise any image manipulation software, I wish to change the compression level of the jpeg file. However, I&#39;m searching for this option that seems to be missing in `ImageIO`. 

Can I set the compression level and how?


  [1]: http://docs.oracle.com/javase/6/docs/api/java/awt/Robot.html
  [2]: http://docs.oracle.com/javase/6/docs/api/javax/imageio/ImageIO.html

Setting jpg compression level with ImageIO in Java

I am trying to convert a Base64String to an image which needs to be saved locally.

At the moment, my code is able to save the image but when I open the saved image, it says &quot;Invalid Image&quot;.

![enter image description here][1]


  [1]: http://i.stack.imgur.com/s6aIa.png

Code:

    try
    {
        using (var imageFile = new StreamWriter(filePath))
        {
            imageFile.Write(resizeImage.Content);
            imageFile.Close();
        }
    }

The `Content` is a `string` object which contains the Base64 String.

Content Type	Original Author	Original Content on Stackoverflow
Question	Vineesh Kalarickal	View Question on Stackoverflow
Solution 1 - Pdf	Arkadiusz 'flies' Rzadkowolski	View Answer on Stackoverflow
Solution 2 - Pdf	KenS	View Answer on Stackoverflow
Solution 3 - Pdf	kodybrown	View Answer on Stackoverflow

How to execute ImageMagick to convert only the first page of the multipage PDF to JPEG?

Pdf Problem Overview

Pdf Solutions

Solution 1 - Pdf

Solution 2 - Pdf

Solution 3 - Pdf

Center text vertically in a UITextView

grunt (minimatch/glob) folder exclusion

Attributions