In Linux you can use

    mogrify -crop {Width}x{Height}+{X}+{Y} +repage image.png

for CLI image manipulation

Imagemagick&#39;s convert does the trick for me (and much more than cropping):

    convert -crop +100+10 in.jpg out.jpg

crops 100 pixels off the left border, 10 pixels from the top.

    convert -crop -100+0 in.jpg out.jpg

crops 100 pixels off the right, and so on. The Imagemagick website knows more:

[http://www.imagemagick.org/Usage/crop/#crop][1]


  [1]: http://www.imagemagick.org/Usage/crop/#crop

[Imagemagick][1] is what you want -- tried and true.


  [1]: http://www.imagemagick.org/script/index.php

I found [`nconvert`](http://www.xnview.com/en/xnconvert/) pretty handy so far.

    for f in final/**/*;
    do
       convert -crop 950x654+0+660 &quot;$f&quot; &quot;${f%.jpg}&quot;.jpg
    done

This script loops through all the sub-folders and crops the .jpg files.


macOS has `sips` image processing tool integrated. Cropping functions available are:
```
    -c, --cropToHeightWidth pixelsH pixelsW 
        --cropOffset offsetY offsetH 
```


I have scanned some pages and all ~130 pages needs the lower ~1/8 of the page cut off.  

Using `mogrify` didn&#39;t work for me, 

    a@a-NC210-NC110:/media/a/LG/AC/Learn/Math/Calculus/Workshop/clockwise/aa$ mogrify -quality 100 -crop 2592&#215;1850+0+0 *.jpg  
    mogrify.im6: invalid argument for option `2592&#215;1850+0+0&#39;: -crop @ error/mogrify.c/MogrifyImageCommand/4232.

However `convert` did:
    
    a@a-NC210-NC110:~/Pictures/aa$ convert &#39;*.jpg[2596x1825+0+0]&#39; letter%01d.jpg  
    a@a-NC210-NC110:~/Pictures/aa$

I learnt this [here](http://www.imagemagick.org/script/command-line-processing.php) under the _Inline Image Crop_ section.

Notice my syntax: I had to put my geometry in brackets: `[]`.

Using the successful syntax above but with mogrify simply didn&#39;t work, producing:

    a@a-NC210-NC110:~/Pictures/aa$ mogrify &#39;*.jpg[2596x1825+0+0]&#39; letter%01d.jpg
    mogrify.im6: unable to open image `letter%01d.jpg&#39;: No such file or directory @ error/blob.c/OpenBlob/2638.

_______
    Linux a-NC210-NC110 3.13.0-32-generic #57-Ubuntu SMP Tue Jul 15 03:51:12 UTC 2014 i686 i686 i686 GNU/Linux
    Lubuntu 14.04 LTS



Are there any exemplary examples of the GoF Observer implemented in Python?  I have a bit code which currently has bits of debugging code laced through the key class (currently generating messages to stderr if a magic env is set). Additionally, the class has an interface for incrementally return results as well as storing them (in memory) for post processing.  (The class itself is a job manager for concurrently executing commands on remote machines over ssh).

Currently the usage of the class looks something like:

    job = SSHJobMan(hostlist, cmd)
    job.start()
    while not job.done():
        for each in job.poll():
            incrementally_process(job.results[each])
            time.sleep(0.2) # or other more useful work
    post_process(job.results)

An alernative usage model is:

    job = SSHJobMan(hostlist, cmd)
    job.wait()  # implicitly performs a start()
    process(job.results)

This all works fine for the current utility.  However it does lack flexibility.  For example I currently support a brief output format or a progress bar as incremental results, I also support
brief, complete and &quot;merged message&quot; outputs for the `post_process()` function.

However, I&#39;d like to support multiple results/output streams (progress bar to the terminal, debugging and warnings to a log file, outputs from successful jobs to one file/directory, error messages and other results from non-successful jobs to another, etc).

This sounds like a situation that calls for Observer ... have instances of my class accept registration from other objects and call them back with specific types of events as they occur.

I&#39;m looking at [PyPubSub](http://pypi.python.org/pypi/PyPubSub/) since I saw several references to that in SO related questions.  I&#39;m not sure I&#39;m ready to add the external dependency to my utility but I could see value in using their interface as a model for mine if that&#39;s going to make it easier for others to use.  (The project is intended as both a standalone command line utility and a class for writing other scripts/utilities).

In short I know how to do what I want ... but there are numerous ways to accomplish it.  I want suggestions on what&#39;s most likely to work for other users of the code in the long run.

The code itself is at: [classh](http://bitbucket.org/jimd/classh).




Python Observer Pattern: Examples, Tips?

I have a page with 2 divs. The first one is floated. The 2nd one has a &quot;clear: both&quot; CSS declaration and a big top margin. However, when I view the page in Firefox or IE8, I don&#39;t see the top margin. It looks like the 2nd div is touching the first div, instead of being separated. Is there any way to make the top margin work properly?

I have read the CSS spec and noticed that it says &quot;Since a float is not in the flow, non-positioned block boxes created before and after the float box flow vertically as if the float didn&#39;t exist.&quot;. However, I don&#39;t know what to do about that.

Here is an example:

&lt;!-- begin snippet: js hide: false console: true babel: false --&gt;

&lt;!-- language: lang-html --&gt;

    &lt;!DOCTYPE HTML PUBLIC &quot;-//W3C//DTD HTML 4.01 Transitional//EN&quot; &quot;http://www.w3.org/TR/html4/loose.dtd&quot;&gt;
    &lt;html&gt;&lt;head&gt;
    &lt;meta http-equiv=&quot;Content-Type&quot; content=&quot;text/html; charset=UTF-8&quot;&gt;
    &lt;title&gt;CSS test&lt;/title&gt;
    &lt;/head&gt;
    &lt;body&gt;
         &lt;div style=&quot;float: left; border: solid red 1px&quot;&gt;foo&lt;/div&gt;
         &lt;div style=&quot;clear: both; margin-top: 90px; border: solid red 1px&quot;&gt;This div should not touch the other div.&lt;/div&gt;
    &lt;/body&gt;
    &lt;/html&gt;

&lt;!-- end snippet --&gt;



Why top margin of html element is ignored after floated element?

is there any lightweight command line batch image cropping tool(Linux or Windows) which can handle a variety of the formats ?

Command line batch image cropping tool

<p>is there any lightweight command line batch image cropping tool(Linux or Windows) which can handle a variety of the formats ?</p>


As `Size`, `Width` and `Height` are `Get()` properties of `System.Drawing.Image`;  
How can I resize an Image object at run-time in C#?

Right now, I am just creating a new `Image` using:

    // objImage is the original Image
    Bitmap objBitmap = new Bitmap(objImage, new Size(227, 171));

How to resize an Image C#

Is there a reliable, framework independent way of determining the physical dimensions of a `&lt;img src=&#39;xyz.jpg&#39;&gt;` resized on the client side?



Determine original size of image cross browser?

How can I cache images after they are downloaded from web?

Android image caching

I&#39;m using JavaScript with the jQuery library to manipulate image thumbnails contained in a unordered list. When the image is loaded it does one thing, when an error occurs it does something else. I&#39;m using jQuery `load()` and `error()` methods as events. **After these events I check the image DOM element for the .complete to make sure the image wasn&#39;t already loaded before jQuery could register the events.**

**It works correctly except when an error occurs before jQuery can register the events.** The only solution I can think of is to use the img `onerror` attribute to store a &quot;flag&quot; somewhere globally (or on the node it&#39;s self) that says it failed so jQuery can check that &quot;store/node&quot; when checking .complete.

Anyone have a better solution?

**Edit: Bolded main points and added extra detail below:**
I&#39;m checking if an image is complete (aka loaded) AFTER I add a load and error event on the image. That way, **if the image was loaded before the events were registered, I will still know.** If the image isn&#39;t loaded after the events then the events will take care of it when it does. The problem with this is, I can easily check if an image is loaded already, but *I can&#39;t tell if an error occurred instead.*

Check if an image is loaded (no errors) with jQuery

I want to know how can one actually use a .svg file In a web page?

How to use .svg files in a webpage?

Not sure this is possible, but looking to write a script that would return the average `hex` or `rgb` value for an image.  I know it can be done in AS but looking to do it in JavaScript.  

Get average color of image via Javascript

I&#39;m writing a card game and need my cards to be different sizes in different circumstances. I am storing my images as bitmaps so that they can be quickly drawn and redrawn (for animation).

My problem is that no matter how I try and scale my images (whether through a matrix.postScale, a matrix.preScale, or a createScaledBitmap function) they always come out pixelated and blurry. I know that its the scaling thats causing the problem because the images look perfect when drawn without resizing. 

I have worked through every solution described in these two threads:  
[android quality of the images resized in runtime][1]  
[quality problems when resizing an image at runtime][2]

but still haven&#39;t gotten anywhere. 

I store my bitmaps (into a hashmap) with this code:

    cardImages = new HashMap&lt;Byte, Bitmap&gt;();
	cardImages.put(GameUtil.hearts_ace, BitmapFactory.decodeResource(r, R.drawable.hearts_ace));

and draw them with this method (in a Card class):

    public void drawCard(Canvas c)
	{
		//retrieve the cards image (if it doesn&#39;t already have one)
		if (image == null)
			image = Bitmap.createScaledBitmap(GameUtil.cardImages.get(ID), 
				(int)(GameUtil.standardCardSize.X*scale), (int)(GameUtil.standardCardSize.Y*scale), false);
			
			//this code (non-scaled) looks perfect
			//image = GameUtil.cardImages.get(ID);
			
		matrix.reset();
		matrix.setTranslate(position.X, position.Y);
		
		//These methods make it look worse
		//matrix.preScale(1.3f, 1.3f);
		//matrix.postScale(1.3f, 1.3f);
		
		//This code makes absolutely no difference
		Paint drawPaint = new Paint();
		drawPaint.setAntiAlias(false);
		drawPaint.setFilterBitmap(false);
		drawPaint.setDither(true);
		
		c.drawBitmap(image, matrix, drawPaint);
	}

Any insight would be greatly appreciated. Thanks


  [1]: https://stackoverflow.com/questions/2041207/android-quality-of-the-images-resized-in-runtime
  [2]: https://stackoverflow.com/questions/4231817/quality-problems-when-resizing-an-image-at-runtime

Bad image quality after resizing/scaling bitmap

I&#39;m trying to dynamically scale text to be placed on images of varying but known dimensions. The text will be applied as a watermark.  Is there any way to scale the text in relation to the image dimensions?  I don&#39;t require that the text take up the whole surface area, just to be visible enough so its easily identifiable and difficult to remove. I&#39;m using Python Imaging Library version 1.1.7. on Linux.

I would like to be able to set the ratio of the text size to the image dimensions, say like 1/10 the size or something.

I have been looking at the font size attribute to change the size but I have had no luck in creating an algorithm to scale it.  I&#39;m wondering if there is a better way.

Any ideas on how I could achieve this?

Thanks

PIL how to scale text size in relation to the size of the image

I need to use [**ImageMagick**][1] as PIL does not have the amount of image functionality available that I am looking for. However, I am wanting to use Python.

The python bindings (PythonMagick) have not been updated since 2009. The only thing I have been able to find is `os.system` calls to use the command line interface but this seems clunky.

Is there any way to access the API directly using `ctypes` and conversions of some sort? 
As a last resort is there any other library out there that has the extensive amount of image editing tools like ImageMagick that I have looked over?


  [1]: http://www.imagemagick.org/script/index.php

Can I access ImageMagick API with Python?

I have bitmaps which are squares or rectangles. I take the shortest side and do something like this:

    int value = 0;
    if (bitmap.getHeight() &lt;= bitmap.getWidth()) {
	    value = bitmap.getHeight();
    } else {
	    value = bitmap.getWidth();
    }

    Bitmap finalBitmap = null;
    finalBitmap = Bitmap.createBitmap(bitmap, 0, 0, value, value);

Then I scale it to a 144 x 144 Bitmap using this:

    Bitmap lastBitmap = null;
    lastBitmap = Bitmap.createScaledBitmap(finalBitmap, 144, 144, true);

Problem is that it crops the top left corner of the original bitmap, Anyone has the code to crop the center of the bitmap?

Android Crop Center of Bitmap

I want to crop image in the way by removing first 30 rows and last 30 rows from the given image. I have searched but did not get the exact solution. Does somebody have some suggestions?

How to crop an image using PIL?

I am trying to find an app that can detect faces in my pictures, make the detected face centered and crop 720 x 720 pixels of the picture. It is rather very time consuming &amp; meticulous to edit around hundreds of pictures I plan to do that.

I have tried doing this using [python opencv mentioned here][1] but I think it is outdated. I&#39;ve also tried [using this][2] but it&#39;s also giving me an error in my system. Also tried using face detection plugin for GIMP but it is designed for GIMP 2.6 but I am using 2.8 on a regular basis. I also tried doing what was posted at ultrahigh blog but it is very outdated (since I&#39;m using a Precise derivative of Ubuntu, while the blogpost was made way back when it was still Hardy). Also tried using Phatch but there is no face detection so some cropped pictures have their face cut right off.

I have tried all of the above and wasted half a day trying to make any of the above do what I needed to do.

Do you guys have suggestion to achieve a goal to around 800 pictures I have.

My operating system is Linux Mint 13 MATE.

Note: I was going to add 2 more links but stackexchange prevented me to post two more links as I don&#39;t have much reputation yet.

  [1]: http://creatingwithcode.com/howto/face-detection-in-static-images-with-python/
  [2]: http://www.givp.org/blog/2011/06/13/image-cropping-and-face-detection/


Detect face then autocrop pictures

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 know that it is impossible to actually modify an image with CSS, which is why I put crop in quotes. 

What I&#39;d like to do is take rectangular images and use CSS to make them appear square without distorting the image at all.

I&#39;d basically like to turn this:

![enter image description here][1]

Into this:

![enter image description here][2]

  [1]: http://i.stack.imgur.com/GA6bB.png
  [2]: http://i.stack.imgur.com/ZPSrK.png

How to &quot;crop&quot; a rectangular image into a square with CSS?

How do you convert an entire directory/folder with ffmpeg via command line or with a batch script?

Content Type	Original Author	Original Content on Stackoverflow
Question	iceman	View Question on Stackoverflow
Solution 1 - Image	Ralph	View Answer on Stackoverflow
Solution 2 - Image	Klaus	View Answer on Stackoverflow
Solution 3 - Image	axel_c	View Answer on Stackoverflow
Solution 4 - Image	Joey	View Answer on Stackoverflow
Solution 5 - Image	Jeffry Anto	View Answer on Stackoverflow
Solution 6 - Image	wobmene	View Answer on Stackoverflow
Solution 7 - Image	Mr. Comly	View Answer on Stackoverflow

Command line batch image cropping tool

Image Problem Overview

Image Solutions

Solution 1 - Image

Solution 2 - Image

Solution 3 - Image

Solution 4 - Image

Solution 5 - Image

Solution 6 - Image

Solution 7 - Image

Why top margin of html element is ignored after floated element?

Python Observer Pattern: Examples, Tips?

Attributions