block

问题 I need to divide an image 512*512 into 41*41 overlapping using matlab.In other words, I want to take first a 41*41 block centred in q then I shift by a pixel and I take a 41*41 centered in q+1 and so on.. I can't use Blockproc because it gives a not overlapping block. thanks to help me 回答1: You CAN use BLOCKPROC. It is a bit non-obvious. Set a block size of [1 1], and then use the 'Border' parameter to specify how big a block you want around each pixel: >> a a = 8 1 6 3 5 7 4 9 2 >> blockproc

问题 How to divide a facial image of size 120x120 into 64 blocks of 15x15 pixel size using MATLAB? Then I want to convolve each 15x15 block with Gabor filter. I failed in using the blkproc function.How can I do this? 回答1: To extract these blocks you can use the following, assuming img is a 120x120 image matrix, c=15 , w=8 : blocks = reshape(permute(reshape(img, c, w, c, w), [1 3 2 4]), c, c, w * w) Now blocks is a 15x15x64 matrix, and blocks(:, :, i) is a 15x15 matrix representing the i -th block.

问题 I'm trying to create a program that blocks the signal SIGUSR1 and the it unblocks the signal. In the middle I want to see that the signal is blocked using sigpending . But it always says that the signal isn't blocked, and I can use the signal when it's supposed to be blocked. This is the code that I have. #include <stdlib.h> #include <stdio.h> #include <signal.h> static void signals(int signaln) { switch (signaln) { case SIGUSR1: printf("Signal SIGUSR1\n"); break; } return; } main() { sigset

问题 I program in Objective-C, I know a bit of Scala, Python and Javascript. While I'm comfortable with blocks in Obj-C, I would like to know what specific problem do they solve that I couldn't with the earlier versions of the language. Also - are blocks, closures, function literals, named functions, anonymous functions - one and the same thing? If you can answer with some code examples that would be great. 回答1: First of all, in order to answer the question in the title: Why do we need blocks,

问题 this is my layout xml: <catalog_category_default translate="label"> <label>Catalog Category (Non-Anchor)</label> <reference name="content"> <block type="core/template" name="page.brand" template="page/brand.phtml" /> <block type="catalog/product_list" template="page/accessories.phtml"> <block type="catalog/navigation" name="catalog.leftnav" as="filter_menu" template="catalog/navigation/left.phtml"/> </block> </reference> </catalog_category_default> And from within page.accessories.phtml,

问题 There is an example of javascript blocking from Steve Souders from his Book 'High Performance Web Sites': http://stevesouders.com/hpws/js-blocking.php Javascripts don't block Downloads anymore, but still do block rendering. .. but there is a strange download activity: There are 5 parallel downloads (max 6 are possible in Firefox 3 or IE 8 from the same server/host) 4 Images (2 from host1, 2 from host2) 1 Javascript in between there is also a 5th image in the page, but the loading of this

问题 There is an example of javascript blocking from Steve Souders from his Book 'High Performance Web Sites': http://stevesouders.com/hpws/js-blocking.php Javascripts don't block Downloads anymore, but still do block rendering. .. but there is a strange download activity: There are 5 parallel downloads (max 6 are possible in Firefox 3 or IE 8 from the same server/host) 4 Images (2 from host1, 2 from host2) 1 Javascript in between there is also a 5th image in the page, but the loading of this

问题 What I do is this: My class1 (called a method, and expects llamda) -> class2 (also called a method and waiting for a call) -> class3 (recently this class queries the JBoss server AFNetworking) . And use the method AFNetworking: - (AFHTTPRequestOperation *) POST: (NSString *) URLString parameters: (NSDictionary *) parameters constructingBodyWithBlock: (void (^) (id <AFMultipartFormData> FormData)) block success: (void (^) (* AFHTTPRequestOperation operation, responseObject id)) success failure

问题 Before/After call the block, the retaincount is always 1. From apple block doc we know that the self should retain. Can anyone know why? NSLog(@"Before block retain count: %d", [self retainCount]); void (^block)(void) = ^(void){ UIImage* img = [UIImage imageNamed:@"hometown.png"]; [self setImage:img]; NSLog(@"After block retain count: %d", [self retainCount]); }; block(); 回答1: First, retainCount is useless. Don't call it. . Blocks only retain captured objects when the block is copied. Thus,

问题 Is there any way to get hold of the invoked object inside the block thats being called. For instance, is there any way for the blocks to get access to the scope of the method batman or the class SuperHeros class SuperHeros attr_accessor :news def initialize @news = [] end def batman task puts "Batman: #{task} - done" yield "feed cat" @news << task end end cat_woman = lambda do |task| puts "Cat Woman: #{task} - done" # invoker.news << task end robin = lambda do |task| puts "Robin: #{task} -