How to edit image before upload in Yii framework?

you can edit image after image upload from controller

$imgData = UploadedFile::getInstance($model, 'photo');
$photo = resize_image($imgData, 400, 400);

by using this model:

<?php 

namespace backend\models;

Class Resize
{
    // *** Class variables
private $image;
private $width;
private $height;

private $imageResized;

function __construct($fileName)
{
    // *** Open up the file
    $this->image = $this->openImage($fileName);

    // *** Get width and height
    $this->width  = imagesx($this->image);
    $this->height = imagesy($this->image);
}

private function openImage($file)
{
    // *** Get extension
    $extension = strtolower(strrchr($file, '.'));
 
    switch($extension)
    {
        case '.jpg':
        case '.jpeg':
            $img = imagecreatefromjpeg($file);
            break;
        case '.gif':
            $img = imagecreatefromgif($file);
            break;
        case '.png':
            $img = imagecreatefrompng($file);
            break;
        default:
            $img = false;
            break;
    }
    return $img;
}

public function resizeImage($newWidth, $newHeight, $option="auto")
{
 
    // *** Get optimal width and height - based on $option
    $optionArray = $this->getDimensions($newWidth, $newHeight, strtolower($option));
 
    $optimalWidth  = $optionArray['optimalWidth'];
    $optimalHeight = $optionArray['optimalHeight'];
 
    // *** Resample - create image canvas of x, y size
    $this->imageResized = imagecreatetruecolor($optimalWidth, $optimalHeight);
    imagecopyresampled($this->imageResized, $this->image, 0, 0, 0, 0, $optimalWidth, $optimalHeight, $this->width, $this->height);
 
    // *** if option is 'crop', then crop too
    if ($option == 'crop') {
        $this->crop($optimalWidth, $optimalHeight, $newWidth, $newHeight);
    }
}

private function getDimensions($newWidth, $newHeight, $option)
{
 
   switch ($option)
    {
        case 'exact':
            $optimalWidth = $newWidth;
            $optimalHeight= $newHeight;
            break;
        case 'portrait':
            $optimalWidth = $this->getSizeByFixedHeight($newHeight);
            $optimalHeight= $newHeight;
            break;
        case 'landscape':
            $optimalWidth = $newWidth;
            $optimalHeight= $this->getSizeByFixedWidth($newWidth);
            break;
        case 'auto':
            $optionArray = $this->getSizeByAuto($newWidth, $newHeight);
            $optimalWidth = $optionArray['optimalWidth'];
            $optimalHeight = $optionArray['optimalHeight'];
            break;
        case 'crop':
            $optionArray = $this->getOptimalCrop($newWidth, $newHeight);
            $optimalWidth = $optionArray['optimalWidth'];
            $optimalHeight = $optionArray['optimalHeight'];
            break;
    }
    return array('optimalWidth' => $optimalWidth, 'optimalHeight' => $optimalHeight);
}

private function getSizeByFixedHeight($newHeight)
{
    $ratio = $this->width / $this->height;
    $newWidth = $newHeight * $ratio;
    return $newWidth;
}
 
private function getSizeByFixedWidth($newWidth)
{
    $ratio = $this->height / $this->width;
    $newHeight = $newWidth * $ratio;
    return $newHeight;
}
 
private function getSizeByAuto($newWidth, $newHeight)
{
    if ($this->height < $this->width)
    // *** Image to be resized is wider (landscape)
    {
        $optimalWidth = $newWidth;
        $optimalHeight= $this->getSizeByFixedWidth($newWidth);
    }
    elseif ($this->height > $this->width)
    // *** Image to be resized is taller (portrait)
    {
        $optimalWidth = $this->getSizeByFixedHeight($newHeight);
        $optimalHeight= $newHeight;
    }
    else
    // *** Image to be resizerd is a square
    {
        if ($newHeight < $newWidth) {
            $optimalWidth = $newWidth;
            $optimalHeight= $this->getSizeByFixedWidth($newWidth);
        } else if ($newHeight > $newWidth) {
            $optimalWidth = $this->getSizeByFixedHeight($newHeight);
            $optimalHeight= $newHeight;
        } else {
            // *** Sqaure being resized to a square
            $optimalWidth = $newWidth;
            $optimalHeight= $newHeight;
        }
    }
 
    return array('optimalWidth' => $optimalWidth, 'optimalHeight' => $optimalHeight);
}
 
private function getOptimalCrop($newWidth, $newHeight)
{
 
    $heightRatio = $this->height / $newHeight;
    $widthRatio  = $this->width /  $newWidth;
 
    if ($heightRatio < $widthRatio) {
        $optimalRatio = $heightRatio;
    } else {
        $optimalRatio = $widthRatio;
    }
 
    $optimalHeight = $this->height / $optimalRatio;
    $optimalWidth  = $this->width  / $optimalRatio;
 
    return array('optimalWidth' => $optimalWidth, 'optimalHeight' => $optimalHeight);
}

private function crop($optimalWidth, $optimalHeight, $newWidth, $newHeight)
{
    // *** Find center - this will be used for the crop
    $cropStartX = ( $optimalWidth / 2) - ( $newWidth /2 );
    $cropStartY = ( $optimalHeight/ 2) - ( $newHeight/2 );
 
    $crop = $this->imageResized;
    //imagedestroy($this->imageResized);
 
    // *** Now crop from center to exact requested size
    $this->imageResized = imagecreatetruecolor($newWidth , $newHeight);
    imagecopyresampled($this->imageResized, $crop , 0, 0, $cropStartX, $cropStartY, $newWidth, $newHeight , $newWidth, $newHeight);
}

public function saveImage($savePath, $imageQuality="100")
{
    // *** Get extension
    $extension = strrchr($savePath, '.');
    $extension = strtolower($extension);
 
    switch($extension)
    {
        case '.jpg':
        case '.jpeg':
            if (imagetypes() & IMG_JPG) {
                imagejpeg($this->imageResized, $savePath, $imageQuality);
            }
            break;
 
        case '.gif':
            if (imagetypes() & IMG_GIF) {
                imagegif($this->imageResized, $savePath);
            }
            break;
 
        case '.png':
            // *** Scale quality from 0-100 to 0-9
            $scaleQuality = round(($imageQuality/100) * 9);
 
            // *** Invert quality setting as 0 is best, not 9
            $invertScaleQuality = 9 - $scaleQuality;
 
            if (imagetypes() & IMG_PNG) {
                imagepng($this->imageResized, $savePath, $invertScaleQuality);
            }
            break;
 
        // ... etc
 
        default:
            // *** No extension - No save.
            break;
    }
 
    imagedestroy($this->imageResized);
}

}

?>