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• How i can do image CROP in OpenCV

  - by Nolik

  How i can do image crop such in PIL in OpenCV. Working example on PIL im = Image.open('0.png').convert('L') im = im.crop((1, 1, 98, 33)) im.save('_0.png') But how i can do it on OpenCV? I wanted to do so im = cv.imread('0.png', cv.CV_LOAD_IMAGE_GRAYSCALE) (thresh, im_bw) = cv.threshold(im, 128, 255, cv.THRESH_OTSU) im = cv.getRectSubPix(im_bw, (98, 33), (1, 1)) cv.imshow('Img', im) cv.waitKey(0) But it doesnt work. I think, i wrong use getRectSubPix. If it true, please explain how i can correctly use this function. Thanks.

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• Nested Array with one foreach Loop?

  - by streetparade

  I need to have access to a array which looks like this. Array ( [0] => Array ( [54] => Array ( [test] => 54 [tester] => result ) ) ) foreach($array as $key=>$value) { echo $key;// prints 0 echo $value;// prints Array /* now i can iterate through $value but i dont want it solve that way example: foreach($value as $k=>$v) { echo $k;//prints test echo $v; //prints 54 } */ } How can iterate just once ? to get the values of test and tester? I hope i could explain my problem clear

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• Autorelease and properties

  - by ganuke

  I have few questions to ask about the following class #import <Cocoa/Cocoa.h> @interface SomeObject { NSString *title; } @property (retain) NSString *title; @end implementation SomeObject @synthesize title; -(id)init { if (self=[super init]) { self.title=[NSString stringWithFormat:@"allyouneed"]; } return self; } -(void)testMethod{ self.title=[[NSString alloc] init] ; } -(void)dealloc { self.title=nil; [super dealloc]; } In the .h file do we need to declare the title and sub when we add the property. is it not enough to add the @property (retain) NSString *title; line. 2.Do i need to autorelease both assignment to title in the init and testMethod. if So why? Can some one explain these things to me.

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• Jquery-Different between event.target and this keyword?

  - by Jerry

  Hi all Got a quick and might be an newbie question. What is the different between event.target and this? let's say I have $("test").click(function(e){ $thisEventOb=e.target; $this=this; alert($thisEventObj); alert($this); }); I know the alert will pop different value. Anyone could explain the difference? Thanks a million.

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• Confusion with cookie session token and oauth2.0 don't know where to go anymore

  - by byte_slave

  Hi guys, I'm completely confused, frustrated and nothing seems to make sense and work any more. I' dev some iframe fb app and i've been using the javascript sdk (FB.Init()) to get the access_token, but doesn't always work, sometimes i'm already logged into FB and doesn't works... Did some reading, and read also that there is problems using cookies in iframes in Opera and IE, so I was thinking in use the OAuth 2.0 but i'm not sure how via facebook sdk c# and now I'm now completely lost, don't know if i still need to use the javascript FB.Init(). Documentation out there is poor and unclear, a lot of stuff refers to old code, and after hours of reading, jumping on examples, i'm completely messed up and confused. Can some, please, point/explain/enlightening me about this? Thanks a lot guys, appreciated! Merry christmas!

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• After a period of time, nslookup still works, but pinging, and an auto-refeshed website, fails.

  - by Mark Hurd

  Contrary to this question this is for a dotted name (gw.localnet.au), and it doesn't happen straight away. Only after some period of time (quite a long time, possibly days). In fact this is for my ADSL router and its internal IP address which I have named within the router itself and in my Windows Server 2003 Domain Controller DNS Service. Specifically, localnet.au is a Active-Directory-backed primary domain. In fact, an ipconfig /flushdns may fix the problem, but only after a while (about the time it took me to type in this question :-) ). That doesn't explain the root cause though...

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• Cannot seem to communicate between views

  - by devnet247

  Hi all I have written a MVVM prototype as a learning exercise and I am struggling to understand how I can communicate between views.Let me explain I have a treeview on the left (leftSideView) ListView on the right (rightSideView) MainWindow (includes the 2 views mentioned above and a splitter) What I have implemented does not work and I would like you if you can point out where I am going wrong or if there is a better way of doing it. you can download the quick prototype from here http://cid-9db5ae91a2948485.skydrive.live.com/self.aspx/.Public/WpfCommunicationBetweenViews.zip For sure I am doing something wrong with the bindind. Also it would be nice to learn how you do it. EG ListBox on left (one view) ListView On the right (another view) how u communicate between the two. Thanks a lot of any suggestions

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• Need some help in understanding SSL concepts

  - by user1115256

  I am new to SSL programming and finding some difficulties in understanding SSL concepts. I tried to get it through openssl site,but it is not much informative. Here is my doubts. What is difference between SSL Buffer and BIO buffer..? I mean layerwise detail will be very helpful. Can I use SSL_Write and SSL_Read without setting any BIO object to SSL object..? What exactly BIO_flush will do... I mean is it going to flush all the data to network buffer from BIO buffer.. ? If it is possible to do write and read data from SSL directly without using any BIO object then is it possible to flush the data from SSL buffer to network buffer by any means.. ? It would be very helpful if any body explain these things or giving any links where I can find answers to my questions.

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• Repetitive SQL: What does it mean?

  - by Lijo

  Hi In a different post I got a reply that tells about Repetitive SQL. Could you please explain what is Repetitive SQL? http://stackoverflow.com/questions/2657459/sql-code-smells I thought to make it a new post as it is a different subject. The reply says that use of "multiple stored procedures that perform the exact same joins but different filters" can be avoided using VIEWs. Could you please give an example that can only be achieved using repetitive queries, if we are using Stored Proecure? [The same can be achieved without repetition when used VIEWS] Thanks Lijo

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• Is it safe to unset PHP super-globals if this behavior is documented?

  - by Stephen

  I'm building a PHP framework, and in it I have a request object that parses the url as well as the $_GET, $_POST and $_FILE superglobals. I want to encourage safe web habits, so I'm protecting the data against SQL injection, etc. In order to ensure users of this framework are accessing the safe, clean data through the request object, I plan to use unset($_GET, $_POST, $_REQUEST); after parsing those variables. I will document this in the method comments, and explain in the framework documentation that this is happening. My question is: Would this be desirable behavior? What are the potential pitfalls that I have not foreseen?

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• Help with output generated by this C code using fork()

  - by Seephor

  I am trying to figure out the output for a block of C code using fork() and I am having some problems understanding why it comes out the way it does. I understand that when using fork() it starts another instance of the program in parallel and that the child instance will return 0. Could someone explain step by step the output to the block of code below? Thank you. main() { int status, i; for (i=0; i<2; ++i){ printf("At the top of pass %d\n", i); if (fork() == 0){ printf("this is a child, i=%d\n", i); } else { wait(&status); printf("This is a parent, i=%d\n", i); } } }

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• MySQL - Conflicting WHERE and GROUP BY Statements

  - by TaylorPLM

  I have a query returning the counts of some data, but I do NOT want data that has a null value in it... As an example, the code rolls stats from a clicking system into a table. SELECT sh.dropid, ... FROM subscriberhistory sh INNER JOIN subscriberhistory sh2 on sh.subid = sh2.subid WHERE sh.dropid IS NOT NULL AND sh.dropid != "" ... GROUP BY sh.dropid An example of the record set returned would look like this... 400 2 3 4 5 6 401 2 3 6 5 4 NULL 2 3 4 5 1 There are some other where clauses, and a few more selects (as I said, using the count aggregate) that are also within the query. There is also an order by statement. Again, the goal is to keep the NULL data out of the preceding record set. Could someone explain to me why this behavior is occurring and what to do to solve it.

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• Differences between Ruby on Rails versions? Which should I use?

  - by Stephen Kellett

  I first used Rails when it was not so well known about, in 2005. I did some experimental work with it but it has languished due to lack of time. I'm now thinking of persuing the original idea again (with a new implementation) and when researching the latest Ruby and Ruby-on_Rails versions I see Ruby 1.9.2 and a Rails 3.0 beta. I haven't managed to find a concise description of the differences between any of the Rails major versions. I have looked on the official Rails site and a few others as well. No joy. Maybe i'm looking in the wrong places or for the wrong thing? My project isn't commercial in nature (it's a hobby thing) so the beta nature of Rails 3.0 doesn't put me off. I'd just like to know what the differences are. Can anyone explain please? If it makes any odds to the answer, I'll be working on a Linux box and/or a Windows box.

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• Employer wants direct, no-hack, ie6 support for CSS. Should I talk him out of it?

  - by DavidR

  I'm currently employed by a website Designer, he gets the clients and sends me a mockup in a fireworks file, and I send him the html/css/js. The problem is that he wants direct ie6 compatibility for every site I build. That is, no conditional ie6 hack, no separate style sheets. A lot of my html has suffered because of it. I just started writing html with him last summer, he took me in as an intern and taught me everything about it. Since then I built 4 web pages, but I haven't yet made anything I'm really proud of. Should I be trying harder to create stellar code beside my limitations or should I set him down and explain that his demands are killing the code for modern browsers?

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• ASP.NET web services leak memory when (de)serializing disposable objects?

  - by Serilla

  In the following two cases, if Customer is disposable (implementing IDisposable), I believe it will not be disposed by ASP.NET, potentially being the cause of a memory leak: [WebMethod] public Customer FetchCustomer(int id) { return new Customer(id); } [WebMethod] public void SaveCustomer(Customer value) { // save it } This flaw applies to any IDisposable object. So returning a DataSet from a ASP.NET web service, for example, will also result in a memory leak - the DataSet will not be disposed. In my case, Customer opened a database connection which was cleaned up in Dispose - except Dispose was never called resulting in loads of unclosed database connections. I realise there a whole bunch of bad practices being followed here (its only an example anyway), but the point is that ASP.NET - the (de)serializer - is responsible for disposing these objects, so why doesn't it? This is an issue I was aware of for a while, but never got to the bottom of. I'm hoping somebody can confirm what I have found, and perhaps explain if there is a way of dealing with it.

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• I know the big picture but can't put it in place

  - by Simbilim

  Hi, I'm interested in web development and by that I mean the bigger projects like facebook or twitter. I know the basics of java, css, php and mysql. I know there is a lot more out there. I read about it. But I don't know what the purpose is and how to put in place. Things like: Scribe, thrift, casandra, Unix/Linux, shell/perl/python scripting, PostgreSQL, MongoDB, non-relational NoSQL datastores, JVM, nginx I want to know why they need it, how they use it and what te purpose is. What I need is a book like technical background of facebook for dummies or so. Are there any books or websites that explain this from scratch? Thank you!

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• MySQL ODBC error "server has gone away"

  - by digitala

  Occasionally we're seeing an error from ASP pages: Microsoft OLE DB Provider for ODBC Drivers error '80004005' [MySQL][MyODBC 5.00.11][MySQL] 2006 MySQL server has gone away We're handling it the best way we can in ASP but it still crops up. I think it's more to do with the MySQL ODBC driver than the ASP code. We never see this with PHP code we also have running under the same IIS server, however PHP re-connects each time it is ran, whereas I believe the ODBC driver connects once and stays connected. I've checked the settings in the driver but there doesn't seem to be anything I can change to help mitigate the problem. Can anyone explain why this is happening and how to reduce the number of times it happens?

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• Fault exception trashes a register causing a crash in [NSInvocation invoke]

  - by Mike Weller

  I have an NSOperation which fetches some objects from a core data persistent store and sums up a few totals. Sometimes an object is deleted while the operation in in progress, so a core data fault exception occurs. I try/catch the exception while summing to ignore it because I just want to skip objects that cannot be faulted in. However, when one of these fault exceptions occurs (and I swallow it) there is a crash after the invocation returns in [NSInvocation invoke]. It's a bad memory access when dereferencing the value in r10 which according to GDB on a successful run points to one of these: (gdb) x 0x38388348 0x38388348 <OBJC_IVAR_$_NSInvocation._retdata>: 0x00000008 If a fault exception occured a value of 0x02 is in the register which causes the crash. A quick google search tells me that r10 should be saved by the callee, meaning it is not being restored by whatever code is changing it when this exception occurs. Can anybody explain this? I'm not an expert when it comes to these kinds of low-level details

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• Behavior of nested finally in Exceptions

  - by kuriouscoder

  Hello: Today at work, I had to review a code snippet that looks similar to this mock example. package test; import java.io.IOException; import org.apache.log4j.Logger; public class ExceptionTester { public static Logger logger = Logger.getLogger(ExceptionTester.class); public void test() throws IOException { new IOException(); } public static void main(String[] args) { ExceptionTester comparator = new ExceptionTester(); try { try { comparator.test(); } finally { System.out.println("Finally 1"); } } catch(IOException ex) { logger.error("Exception happened" ex); // also close opened resources } System.out.println("Exiting out of the program"); } } It's printing the following output.I expected an compile error since the inner try did not have a catch block. Finally 1 Exiting out of the program I do not understand why IOException is caught by the outer catch block. I would appreciate if anyone can explain this, especially by citing stack unwinding process

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• Screen orientation change forces data re-entry

  - by Timbermar

  I'm developing a simple app, only a handful of activities and nothing to complicated. The issue I'm having is that in a few of my activities I have EditText widgets, and when the screen is rotated, these widgets loose their values. They still visually, that is, on the handset screen, report their values from before the rotation, but to the code report their default values. An example, I have an activity with an EditText, I enter a number, 15, the calculator starts calculating, displays a result. If at this point I rotate to a different orientation, as expected the activity dies, reloads, shows the new orientation, my value of 15 is still in the EditText, however the calculator (the code) calculates as if it was 0, which is the initial value. I have not tried changing the initial value to see if it is really pulling from the default value, or just setting itself to 0 when I cast it as an int. If I didn't explain this well enough, let me know, I can add source code if I need to. Thanks.

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• Function declaration in C and C++

  - by Happy Mittal

  I have two C++ files, say file1.cpp and file2.cpp as //file1.cpp #include<cstdio> void fun(int i) { printf("%d\n",i); } //file2.cpp void fun(double); int main() { fun(5); } When I compile them and link them as c++ files, I get an error "undefined reference to fun(double)". But when I do this as C files, I don't get error and 0 is printed instead of 5. Please explain the reason. Moreover I want to ask whether we need to declare a function before defining it because I haven't declared it in file1.cpp but no error comes in compilation.

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• How to change code settings in eclipse

  - by Maven

  Sorry if the question title is confusing. Let me explain further. I am building a Java project with Eclipse. In my Java product I have conditionals that determine what code is included in the product and relies on static final constants for dead stripping. class BuildFlags { public static final boolean SOME_FLAG = true; // Need to set this programmatically } class SomeOtherClass { public void someMethod() { if (BuildFlags.SOME_FLAG) { // flag specific code } } } My question is how can I change BuildFlags.SOME_FLAG (above) so that I can run a special build without changing the source? Is there some way I can pass flags to the jvm (from eclipse) which I can then access to set this flag programatically?

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• Weird behavior in referring to global variable. Is this a bug in javascript? Surely it isn't!

  - by Chandan .

  Consider the following piece of code. <html> <body> <script> var x = 5; //globally declared function showX() { alert("x="+x); //trying to display global value var x=10; //trying to create and initialize a local x } </script> <input type = "button" value="Show X" onclick="showX()"> </body> </html> The alert statement shows 'x=undefined'. And doesn't print the global value of x as expected. An equivalent java code would display 5! So, is it a bug? If not then how does one explain that behavior?

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• Looping differences in Ruby using Range vs. Times

  - by jbjuly

  I'm trying to solve a Project Euler problem using Ruby, I used 4 different looping methods, the for-loop, times, range and upto method, however the for-loop and times method only produces the expected answer, while the range and upto method does not. I'm assuming that they are somewhat the same, but I found out it's not. Can someone please explain the differences between these methods? Here's the looping structure I used # for-loop method for n in 0..1 puts n end 0 1 => 0..1 # times method 2.times do |n| puts n end 0 1 => 2 # range method (0..1).each do |n| puts n end 0 1 => 0..1 # upto method 0.upto(1) do |n| puts n end 0 1 => 0

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• Axis xsd:dateTime issue

  - by milostrivun

  Here is the whole thing. I 'm using a webservice, with wsdl2java I generate classes and communicate with another application. Problem is , when I use a method from my generated WS client that is resulting in data that contains some object with data in format xsd:dateTime(Axis 1.4), and that data is represensted by java.util.Calendar object in java has time shifted to GMT(about two hours before my time zone). That results in bad data that I have to substract two hours to display correct value. My question is, considering I didn't work on building that webservice(all I have is wsdl url) where is the problem and can I fix it or the problem is at the side of the webservice creator. If I'm it is not clear what I am asking I will gladly explain as much as I can.

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