How To Resize Image Keeping Constraints Php

I have made two GIFs to explain what I am trying to do. Where the grey border is the dimensions I am after (700*525). They are at the bottom of this question. I want for all images

Solution 1:

The below code should do what you want. I've not tested it extensively but it seems to work on the few test images I made. There's a niggling doubt at the back of mind that somewhere my math is wrong, but it's late and I can't see anything obvious.

Edit: It niggled enough I went through again and found the bug, which was that the crop wasn't in the middle of the image. Code replaced with working version.

In short: treat this as a starting point, not production-ready code!

<?php// set image size constraints.$target_w = 525;
$target_h = 700;

// get image.$in = imagecreatefrompng('<path to your>.png');

// get image dimensions.$w = imagesx($in);
$h = imagesy($in);

if ($w >= $target_w && $h >= $target_h) {
    // get scales.$x_scale = ($w / $target_w);
    $y_scale = ($h / $target_h);

    // create new image.$out = imagecreatetruecolor($target_w, $target_h);

    $new_w = $target_w;
    $new_h = $target_h;
    $src_x = 0;
    $src_y = 0;

    // compare scales to ensure we crop whichever is smaller: top/bottom or// left/right.if ($x_scale > $y_scale) {
        $new_w = $w / $y_scale;

        // see description of $src_y, below.$src_x = (($new_w - $target_w) / 2) * $y_scale;
    } else {
        $new_h = $h / $x_scale;

        // a bit tricky. crop is done by specifying coordinates to copy from in// source image. so calculate how much to remove from new image and// then scale that up to original. result is out by ~1px but good enough.$src_y = (($new_h - $target_h) / 2) * $x_scale;
    }

    // given the right inputs, this takes care of crop and resize and gives// back the new image. note that imagecopyresized() is possibly quicker, but// imagecopyresampled() gives better quality.
    imagecopyresampled($out, $in, 0, 0, $src_x, $src_y, $new_w, $new_h, $w, $h);

    // output to browser.
    header('Content-Type: image/png');
    imagepng($out);
    exit;

} else {
    echo'image too small';
}

?>

Solution 2:

Using Imagick :

define('PHOTO_WIDTH_THUMB', 700);
define('PHOTO_HEIGHT_THUMB', 525);

$image = new Imagick();
$image->readImage($file_source);
$width = $image->getImageWidth();
$height = $image->getImageHeight();

if($width > $height){
  $image->thumbnailImage(0, PHOTO_HEIGHT_THUMB);
}else{
  $image->thumbnailImage(PHOTO_WIDTH_THUMB, 0);
}

$thumb_width = $image->getImageWidth();
$thumb_height = $image->getImageHeight();
$x = ($thumb_width - PHOTO_WIDTH_THUMB)/2;
$y = ($thumb_height - PHOTO_HEIGHT_THUMB)/2;
$image->cropImage(PHOTO_THUMB_WIDTH, PHOTO_THUMB_HEIGHT, $x, $y);
$image->writeImage($thumb_destination);

$image->clear();
$image->destroy();
unlink($file_source);

Solution 3:

I have used GD library to accomplish the resize. Basically what I did is, I calculated the image dimension and then resized the image to dimension 700x525 from the center.

<?php/*
 * PHP GD
 * resize an image using GD library
 *///the image has 700X525 px ie 4:3 ratio$src = 'demo_files/bobo.jpg';

// Get new sizeslist($width, $height) = getimagesize($src);

$x = 0;
$y = 0;
if($width < $height){
    $newwidth = $width;
    $newheight = 3/4 * $width;
    $x = 0;
    $y = $height/2 - $newheight/2;
}else{
    $newheight = $height;
    $newwidth = 4/3 * $height;
    $x=$width/2 - $newwidth/2;
    $y=0;

}

$targ_w = 700; //width of the image to be resized to$targ_h = 525; ////height of the image to be resized to$jpeg_quality = 90;

$img_r = imagecreatefromjpeg($src);
$dst_r = ImageCreateTrueColor( $targ_w, $targ_h );

imagecopyresampled($dst_r,$img_r,0,0,$x,$y,$targ_w,$targ_h,$newwidth,$newheight);

header('Content-type: image/jpeg');
imagejpeg($dst_r,null,$jpeg_quality);

exit;

?>

Solution 4:

i used http://phpthumb.sourceforge.net to have a beutiful solution also with transparent curved edges.

this is an alternative route to solution, might suit someone's need with little configuration.