创建完美缩略图

The following code is working without any error, but my problem is when i create a thumbnail some times thumbnail are non understandable one ( some conditions such as width is very larger than height ) i also tried a code for calculate height automatically.But it won't perfectly works. I want a code which creates a understandable thumbnail every time.(cropped thumbnail can be generated )

function make_thumb($src, $dest, $desired_width)
{
    $source_image = imagecreatefromjpeg($src);
    $width = imagesx($source_image);
    $height = imagesy($source_image);

    //even if height is calculated automatically using
    $desired_height = floor($height * ($desired_width / $width));

    $virtual_image = imagecreatetruecolor($desired_width, $desired_height);
    imagecopyresampled($virtual_image, $source_image, 0, 0, 0, 0, $desired_width, $desired_height, $width, $height);
    imagejpeg($virtual_image, $dest);
}

You can use the Class SimpleImage, like:

// Usage:
// Load the original image
$image = new SimpleImage('lemon.jpg');

// Resize the image to 600px width and the proportional height
$image->resizeToWidth(600);
$image->save('lemon_resized.jpg');

You can find this class here on github https://gist.github.com/miguelxt/908143

I've written a script to make thumb of landscape or portrait images. May be this will help you

<?php
    $thumbWidth = 200; // can change it to whatever required
    $thumbHeight = 200; // can change it to whatever required

    $img = imagecreatefromstring(file_get_contents('SAM_1883.JPG'));
    $imgWidth = imagesx($img);
    $imgHeight = imagesy($img);

    $imgStart_x = 0;
    $imgStart_y = 0;
    $imgEnd_x = $imgWidth;
    $imgEnd_y = $imgHeight;

    if($imgWidth > $imgHeight){
        $diff = $imgWidth - $imgHeight;
        $imgStart_x = $diff / 2;
        $imgEnd_x = $imgWidth - $diff;
    }else{
        $diff = $imgHeight - $imgWidth;
        $imgEnd_y = $imgHeight - $diff;
    }

    $dest = imagecreatetruecolor($thumbHeight,$thumbHeight);
    imagecopyresized($dest, $img, 0, 0, $imgStart_x, $imgStart_y, $thumbWidth, $thumbHeight, $imgEnd_x, $imgEnd_y);
    imagePNG($dest,'abc'.rand(0,9999).'.png');
?>

However you can change the source, thumbWidth, thumbHeight and destination of thumb as per your requirement.

https://github.com/lencioni/SLIR can resize your image on the fly. It will cache the image on the server as well as make it cacheable on the browser and proxy servers. The resizing happens when loading the image, not when loading HTML so your HTML is loading faster.