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Showing posts with label Browsers. Show all posts
Showing posts with label Browsers. Show all posts

Tuesday, 21 July 2015

CwebP Unsupported Color Conversion Request:

    When i am creating WebP images, that time triggering the error as "cwebp unsupported color conversion request, Error Could not be process file".


    $imageName  = "ilikekaraikudi.jpg";
    $webpimgName  = "ilikekaraikudi.webp";
   cwebp -q 0 ".$imageName." -o ".$webpimgName.
   Unsupported color conversion request
   Error! Could not process file ilikekaraikudi.jpg
   Error! Cannot read input picture 



    we can try converting to RBG color-space via ImageMagick (convert) or any other image-editor tool.

    exec("convert -colorspace RGB ".$imageName." ".$webpimgName . " ");

Related Posts:

   1. how to create webp image in php
   2. fedex shipping integration
   3. 413 “Request Entity Too Large” error with uploading a file

   4. How to blink text in html for various browsers
   5. Difference between cookies and sessions in php


Thursday, 16 July 2015


    WebP is an image file type that was created in 2010 and is created by Google. This image format provides lossless and lossy compression to images on the server. Big social media websites are using WebP image process are Google, Facebook and EBay.
  WebP images natively supporting to the following browsers are Chrome, Opera, Opera Mini, Android Browser and Chrome for Android browsers only. It is not supported any other browsers like Firefox, IE and Safari,etc.


    WebP lossless image files are 26% smaller than PNGs.
    WebP lossy images files are 25-34% smaller than JPEG images at equivalent SSIM index.
    WebP supports lossless transparency (also known as alpha channel) with just 22% more bytes.

WebP images creating process in php:

you can use following php commands,to get the webp images

$imgName     =   "codingslovers.jpg";
$webPName   =   "codingslovers.webp";


 cwebp [quality qualitypercentage] [source image] -o [destination]

exec("cwebp -q 0 ".$imgName." -o ".$webPName." ");

Another Method:

exec("convert -colorspace RGB ".$imgName." ".$webPName . " ");

Exec : executes the given command in php

Advantages of WebP:

Smaller file size
Different compression algorithm
Smoother color gradations
Alpha channel mask

Disadvantages of WebP:

Weak browser support
Artifacting has plastic appearance
Poor exporting interface

Browserwise WebP Performance:

Wednesday, 25 February 2015

Expire the session after some peiod of time by using in php.

Basically, two methods are available to destory the sessions.

   1. session_destroy()
   2. unset($_SESSION['testvaraible'])
   3. setting the time out for this session


     if we will call the session_destroy(), it will destroy all the SESSION variable.It is no need any other parameters.


2. unset($_SESSION['testvaraible'])

       When we will call the unset() ,it will destroyed the particular variable.
 // Destroyed the session variable "testvaraible".


3. setting the time out for this session


(time() - $_SESSION['LAST_MINITUte_ACTIVITY'] > 1800)) { // last request was more than 30 minutes ago session_unset(); // unset $_SESSION variable for the run-time session_destroy(); // destroy session data in storage } // update last activity time stamp $_SESSION['LAST_MINITUte_ACTIVITY'] = time(); /* You can also use an additional time stamp to regenerate the session ID periodically,to avoid attacks on sessions like session fixation: */ if (!isset($_SESSION['CREATED'])) { $_SESSION['CREATED'] = time(); } else if (time() - $_SESSION['CREATED'] > 1800) { // session started more than 30 minutes ago // change session ID for the current session // an invalidate old session ID session_regenerate_id(true); $_SESSION['CREATED'] = time(); // update creation time }


   By using php ini_set session.gc_maxlifetime also we will expire the session.

 ini_set session.gc_maxlifetime


Saturday, 10 January 2015

How to resolved when Logged out sessions get restored by back button?

When we log out the sessions , We clear the cookies in browser. But when we press the back button after logging out the session gets restored. 

 header("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1
 header("Expires: Sat, 26 Jul 1997 05:00:00 GMT"); // Date in the past

Sunday, 30 November 2014

Contains() Property in javascript.,it is working fine in Mozila Firebox only.It will not support Chrome Browser,Internet Browser,Safari,Opera browser.

Mozila Browser :

  var ClearFilterValue  = 'family Schools';
    if(ClearFilterValue.contains("family")== true) {

Chorme & Mozila Firebox Browser :

    The below javascript index() properity will working for both chrome and mozile firbox.It is functionality similar to contains property.

var ClearFilterValue  = 'family Schools';
alert(ClearFilterValue.indexOf("family") != -1);

var n  =   str.indexOf("family"); 
if(n >= 0) { 

Friday, 30 May 2014

How to blink text in html for various browsers

The blink() method is not standard, and may not work as expected in all browsers.
The blink() method is used to display a blinking string.
This method returns the string embedded in the <blink> tag, like this:


Note:  The blink() method only works in Opera. It is not supported in Internet Explorer, Firefox, Chrome, or Safari.

So alternatively we can try this below:

<span class="blink_text">India's Largest portal is</span> 
<style type="text/css"> 
.blink_text { 

        -webkit-animation-name: blinker;
 -webkit-animation-duration: 1s;
 -webkit-animation-timing-function: linear;
 -webkit-animation-iteration-count: infinite;

 -moz-animation-name: blinker;
 -moz-animation-duration: 1s;
 -moz-animation-timing-function: linear;
 -moz-animation-iteration-count: infinite;
 animation-name: blinker;
 animation-duration: 1s;
 animation-timing-function: linear; 
    animation-iteration-count: infinite; color: red; 

@-moz-keyframes blinker {
    0% { opacity: 1.0; }
    50% { opacity: 0.0; }
    100% { opacity: 1.0; } 

@-webkit-keyframes blinker {  
    0% { opacity: 1.0; }
    50% { opacity: 0.0; }
    100% { opacity: 1.0; } 

@keyframes blinker {  
    0% { opacity: 1.0; } 
    50% { opacity: 0.0; }      
    100% { opacity: 1.0; }