Search Results

Search found 7107 results on 285 pages for 'processing efficiency'.

Page 55/285 | < Previous Page | 51 52 53 54 55 56 57 58 59 60 61 62  | Next Page >

  • Why does this code read all ' ' for the anything after the 4th character?

    - by djs22
    #define fileSize 100000 int main(int argc, char *argv[]){ char *name=argv[1]; char ret[fileSize]; FILE *fl = fopen(name, "rb"); fseek(fl, 0, SEEK_END); long len = fileSize; fseek(fl, 0, SEEK_SET); //fread(ret, 1, len, fl); int i; *(ret+fileSize) = '\0'; for (i=0; i<fileSize; i++){ *(ret+i)=fgetc(fl); printf("byte : %s \n", ret); } fclose(fl); } In the above code, when I feed the name of a jpeg file, it reads anything after the 4th character as ' '...any ideas? Thanks!

    Read the article

  • Creating thumbnails PHP problem

    - by Wayne
    I have this source code where I got it from net tutsplus. I have configured it and made it work in one PHP file. It does work by transferring the original image, but it does not generate to the thumbnails folder. <?php $final_width_of_image = 100; $path_to_image_directory = "../../img/events/" . urldecode($_GET['name']) . "/"; $path_to_thumbs_directory = "../../img/events/" . urldecode($_GET['name']) . "/thumbnails/"; function createThumbnail($filename) { if(preg_match('/[.](jpg)$/', $filename)) { $im = imagecreatefromjpeg($path_to_image_directory . $filename); } elseif(preg_match('/[.](gif)$/', $filename)) { $im = imagecreatefromgif($path_to_image_directory . $filename); } elseif(preg_match('/[.](png)$/', $filename)) { $im = imagecreatefrompng($path_to_image_directory . $filename); } $ox = imagesx($im); $oy = imagesy($im); $nx = $final_width_of_image; $ny = floor($oy * ($final_width_of_image / $ox)); $nm = imagecreatetruecolor($nx, $ny); imagecopyresized($nm, $im, 0,0,0,0,$nx,$ny,$ox,$oy); imagejpeg($nm, $path_to_thumbs_directory . $filename); $tn = '<img src="' . $path_to_thumbs_directory . $filename . '" alt="image" />'; echo $tn; } if(isset($_FILES['fupload'])) { if(preg_match('/[.](jpg)|(gif)|(png)$/', $_FILES['fupload']['name'])) { $filename = $_FILES['fupload']['name']; $source = $_FILES['fupload']['tmp_name']; $target = $path_to_image_directory . $filename; move_uploaded_file($source, $target); createThumbnail($filename); } } ?> Basically it is supposed to generate a thumbnail of the uploaded image and store the original image into a different folder. The paths are correct, it works by getting the folder name in the URL, it does work, but nothing works for the thumbnails folder. BEFORE you ask this related question, yes, thumbnails generation does work on my server by the PHP GD, I have tested it separately. So this is not the problem. :) How do I get this to work? :(

    Read the article

  • What is the best algorithm to locate a point in an image file?

    - by suugaku
    Hi all, I want to create a mark sheet recognizer. Here is the description: My system uses black and white color scheme. The mark sheet paper has a small black rectangle on each corner and an additional small black rectangle, to determine orientation, near one of the previous rectangles. The paper is scanned to yield an image (in bmp format for example). The first step is to locate these five references in image as eficient as possible. My rough idea is to trace row by row and from left to right for each row. It sounds very slow I think. Is there any better way to do that? Thank you in advance. regards, Suugaku

    Read the article

  • Detect Rotation of a scanned image in C#

    - by ahmed fouad
    We want a c# solution to correct the scanned image because it is rotated. To solve this problem we must detect the rotation angle first and then rotate the image. This was our first thought for our problem. But then we thought image warping would be more accurate as I think it would make the scanned image like our template. Then we can process it as we know all the coordinates of our template... I searched for a free SDK or a free solution in c#. Helping me in this will be great as it is the last task in our work. Really, thanks for all.

    Read the article

  • Parallel version of loop not faster than serial version

    - by Il-Bhima
    I'm writing a program in C++ to perform a simulation of particular system. For each timestep, the biggest part of the execution is taking up by a single loop. Fortunately this is embarassingly parallel, so I decided to use Boost Threads to parallelize it (I'm running on a 2 core machine). I would expect at speedup close to 2 times the serial version, since there is no locking. However I am finding that there is no speedup at all. I implemented the parallel version of the loop as follows: Wake up the two threads (they are blocked on a barrier). Each thread then performs the following: Atomically fetch and increment a global counter. Retrieve the particle with that index. Perform the computation on that particle, storing the result in a separate array Wait on a job finished barrier The main thread waits on the job finished barrier. I used this approach since it should provide good load balancing (since each computation may take differing amounts of time). I am really curious as to what could possibly cause this slowdown. I always read that atomic variables are fast, but now I'm starting to wonder whether they have their performance costs. If anybody has some ideas what to look for or any hints I would really appreciate it. I've been bashing my head on it for a week, and profiling has not revealed much.

    Read the article

  • How to mask part of an image in matlab ?

    - by ZaZu
    Hey guys, I would like to know how to mask part of an image that is in BLACK & WHITE ? I got an object that needs to be edge detected, but I have other white interfering objects in the background that are below the target objet ... I would like to mask the entire lower part of an image to black, how can I do that ? Thanks !!

    Read the article

  • Parallel.For maintain input list order on output list

    - by romeozor
    I'd like some input on keeping the order of a list during heavy-duty operations that I decided to try to do in a parallel manner to see if it boosts performance. (It did!) I came up with a solution, but since this was my first attempt at anything parallel, I'd need someone to slap my hands if I did something very stupid. There's a query that returns a list of card owners, sorted by name, then by date of birth. This needs to be rendered in a table on a web page (ASP.Net WebForms). The original coder decided he would construct the table cell-by-cell (TableCell), add them to rows (TableRow), then each row to the table. So no GridView, allegedly its performance is bad, but the performance was very poor regardless :). The database query returns in no time, the most time is spent on looping through the results and adding table cells etc. I made the following method to maintain the original order of the list: private TableRow[] ComposeRows(List<CardHolder> queryResult) { int queryElementsCount = queryResult.Count(); // array with the query's size var rowArray = new TableRow[queryElementsCount]; Parallel.For(0, queryElementsCount, i => { var row = new TableRow(); var cell = new TableCell(); // various operations, including simple ones such as: cell.Text = queryResult[i].Name; row.Cells.Add(cell); // here I'm adding the current item to it's original index // to maintain order in the output list rowArray[i] = row; }); return rowArray; } So as you can see, because I'm returning a very different type of data (List<CardHolder> -> TableRow[]), I can't just simply omit the ordering from the original query to do it after the operations. Also, I also thought it would be a good idea to Dispose() the objects at the end of each loop, because the query can return a huge list and letting cell and row objects pile up in the heap could impact performance.(?) How badly did I do? Does anyone have a better solution in case mine is flawed?

    Read the article

  • PHP image resize and rounded image corners dynamically

    - by Dan
    I'm working of a script that dynamically ads rounded edges to an image then crops it down to a certain size. At the moment the script ads the rounded edges to the picture but i cannot get it so the original image is resized to fit within the dimensons of the final outputted image (140px x 120px) The problem is that the orginal uploaded image depending on it's orginal dimensions change the size it is in the final PNG { $image_file = $_FILES['image']['tmp_name']; $corner_radius = isset($_GET['radius']) ? $_GET['radius'] : 20; // The default corner radius is set to 20px $topleft = (isset($_GET['topleft']) and $_GET['topleft'] == "no") ? false : true; // Top-left rounded corner is shown by default $bottomleft = (isset($_GET['bottomleft']) and $_GET['bottomleft'] == "no") ? false : true; // Bottom-left rounded corner is shown by default $bottomright = (isset($_GET['bottomright']) and $_GET['bottomright'] == "no") ? false : true; // Bottom-right rounded corner is shown by default $topright = (isset($_GET['topright']) and $_GET['topright'] == "no") ? false : true; // Top-right rounded corner is shown by default $imagetype=$_FILES['image']['type']; $endsize=$corner_radius; $startsize=$endsize*3-1; $arcsize=$startsize*2+1; if (($imagetype=='image/jpeg') or ($imagetype=='jpg')) { $image = imagecreatefromjpeg($image_file); } else { if (($imagetype=='GIF') or ($imagetype=='gif')) { $image = imagecreatefromgif($image_file); } else { $image = imagecreatefrompng($image_file); } } $forecolor ='#ffffff'; $size = getimagesize($image_file); // Top-left corner $background = imagecreatetruecolor($size[0],$size[1]); imagecopymerge($background, $image, 0, 0, 0, 0, $size[0], $size[1], 100); $startx=$size[0]*2-1; $starty=$size[1]*2-1; $im_temp = imagecreatetruecolor($startx,$starty); imagecopyresampled($im_temp, $background, 0, 0, 0, 0, $startx, $starty, $size[0], $size[1]); $bg = imagecolorallocate($im_temp, 255,255,255); $fg = imagecolorallocate($im_temp, 255,255,255); if ($topleft == true) { if(!imagearc($im_temp, $startsize, $startsize, $arcsize, $arcsize, 180,270,$bg))echo "nope"; imagefilltoborder($im_temp,0,0,$bg,$bg); } // Bottom-left corner // Top-right corner if ($topright == true) { imagearc($im_temp, $startx-$startsize, $startsize,$arcsize, $arcsize, 270,360,$bg); imagefilltoborder($im_temp,$startx,0,$bg,$bg); } $image = imagecreatetruecolor(140,120); imagecopyresampled($image, $im_temp, 0, 0, 0, 0, $size[0],$size[1],$starty+1310,$startx+1500); // Output final image if(!imagepng($image,'hello.png')) echo "boo"; if(!imagedestroy($image)) echo "2"; if(!imagedestroy($background)) echo "3"; if(!imagedestroy($im_temp)) echo "4"; } EDIT: My question is how to get the orginal image reized so it fits into the 140 x 120 image that is processed with the rounded edges?

    Read the article

  • How to generate irregular ball shapes?

    - by tomato
    What kind of algorithms would generate random "goo balls" like those in World of Goo. (btw, if you haven't played it yet, highly recommended). I'm using Proccesing, but any generic algorithm would do. I guess it boils down to how to "randomly" make balls that are kind of round, but not perfectly round, and still looking realistic. Thanks in advance!

    Read the article

  • Parallel For Loop - Problems when adding to a List

    - by Kevin Crowell
    I am having some issues involving Parallel for loops and adding to a List. The problem is, the same code may generate different output at different times. I have set up some test code below. In this code, I create a List of 10,000 int values. 1/10th of the values will be 0, 1/10th of the values will be 1, all the way up to 1/10th of the values being 9. After setting up this List, I setup a Parallel for loop that iterates through the list. If the current number is 0, I add a value to a new List. After the Parallel for loop completes, I output the size of the list. The size should always be 1,000. Most of the time, the correct answer is given. However, I have seen 3 possible incorrect outcomes occur: The size of the list is less than 1,000 An IndexOutOfRangeException occurs @ doubleList.Add(0.0); An ArgumentException occurs @ doubleList.Add(0.0); The message for the ArgumentException given was: Destination array was not long enough. Check destIndex and length, and the array's lower bounds. What could be causing the errors? Is this a .Net bug? Is there something I can do to prevent this from happening? Please try the code for yourself. If you do not get an error, try it a few times. Please also note that you probably will not see any errors using a single-core machine. using System; using System.Collections.Generic; using System.Threading.Tasks; namespace ParallelTest { class Program { static void Main(string[] args) { List<int> intList = new List<int>(); List<double> doubleList = new List<double>(); for (int i = 0; i < 250; i++) { intList.Clear(); doubleList.Clear(); for (int j = 0; j < 10000; j++) { intList.Add(j % 10); } Parallel.For(0, intList.Count, j => { if (intList[j] == 0) { doubleList.Add(0.0); } }); if (doubleList.Count != 1000) { Console.WriteLine("On iteration " + i + ": List size = " + doubleList.Count); } } Console.WriteLine("\nPress any key to exit."); Console.ReadKey(); } } }

    Read the article

  • How to detect an 'image area' percentage inside an image?

    - by DaNieL
    Mhh, kinda hard to explain with my poor english ;) So, lets say I have an image, doesnt matter what kind of (gif, jpg, png) with 200x200 pixel size (total area 40000 pixels) This image have a background, that can be trasparent, or every color (but i know the background-color in advance). Lets say that in the middle of this image, there is a picture (for keep the example simple lets suppose is a square drawn), of 100x100 pixels (total area 10000 pixels). I need to know the area percentage that the small square fill inside the image. So, in i know the full image size and the background-color, there is a way in php/python to scan the image and retrieve that (in short, counting the pixel that are different from the given background)? In the above example, the result should be 25%

    Read the article

  • Parallelizing some LINQ to XML

    - by Lol coder
    How can I make this code run in parallel? List<Crop> crops = new List<Crop>(); //Get up to 10 pages of data. for (int i = 1; i < 10; i++) { //i is basically used for paging. XDocument document = XDocument.Load(string.Format(url, i)); crops.AddRange(from c in document.Descendants("CropType") select new Crop { //The data here. }); }

    Read the article

  • How to scale JPEG image down so that text is clear as possible?

    - by Juha Syrjälä
    I have some JPEG images that I need scale down to about 80% of original size. Original image dimension are about 700px × 1000px. Images contain some computer generated text and possibly some graphics (similar to what you would find in corporate word documents). How to scale image so that the text is as legible as possible? Currently we are scaling the imaeg down using bicubic interpolation, but that makes the text blurry and foggy.

    Read the article

  • How to use parallel execution in a shell script?

    - by eSKay
    I have a C shell script that does something like this: #!/bin/csh gcc example.c -o ex gcc combine.c -o combine ex file1 r1 <-- 1 ex file2 r2 <-- 2 ex file3 r3 <-- 3 #... many more like the above combine r1 r2 r3 final \rm r1 r2 r3 Is there some way I can make lines 1, 2 and 3 run in parallel instead of one after the another?

    Read the article

  • Stack usage with MMX intrinsics and Microsoft C++

    - by arik-funke
    I have an inline assembler loop that cumulatively adds elements from an int32 data array with MMX instructions. In particular, it uses the fact that the MMX registers can accommodate 16 int32s to calculate 16 different cumulative sums in parallel. I would now like to convert this piece of code to MMX intrinsics but I am afraid that I will suffer a performance penalty because one cannot explicitly intruct the compiler to use the 8 MMX registers to accomulate 16 independent sums. Can anybody comment on this and maybe propose a solution on how to convert the piece of code below to use intrinsics? == inline assembler (only part within the loop) == paddd mm0, [esi+edx+8*0] ; add first & second pair of int32 elements paddd mm1, [esi+edx+8*1] ; add third & fourth pair of int32 elements ... paddd mm2, [esi+edx+8*2] paddd mm3, [esi+edx+8*3] paddd mm4, [esi+edx+8*4] paddd mm5, [esi+edx+8*5] paddd mm6, [esi+edx+8*6] paddd mm7, [esi+edx+8*7] ; add 15th & 16th pair of int32 elements esi points to the beginning of the data array edx provides the offset in the data array for the current loop iteration the data array is arranged such that the elements for the 16 independent sums are interleaved.

    Read the article

< Previous Page | 51 52 53 54 55 56 57 58 59 60 61 62  | Next Page >