PHP crop image to fix width and height without losing dimension ratio

Question

hi, im looking to create thumbnails that has 100px by 100px dimension. i've seen many articles explaining the methods but most end up having the width!=height if the dimension ratio is to be kept.

for example, i have a 450px by 350px image. i would like to crop to 100px by 100px. if i were to keep the ratio, i would end up having 100px by 77px. this makes it ugly when im listing these images in a row and column. however, a image without dimension ratio will look terrible as well.

i've seen images from flickr and they look fantastic. for example:
thumbnail: http://farm1.static.flickr.com/23/32608803_29470dfeeb_s.jpg
medium size: http://farm1.static.flickr.com/23/32608803_29470dfeeb.jpg
large size: http://farm1.static.flickr.com/23/32608803_29470dfeeb_b.jpg

tks

Answer 1

This is fairly simple with ImageMagick and PHP. Have a look at Different aspects of thumbnailing, and Again some examples..cropThumbnailImage() on Mikko's Blog.

Answer 2

This is done by only using a part of the image as the thumbnail which has a 1:1 aspect ratio (mostly the center of the image). If you look closely you can see it in the flickr thumbnail.

Because you have "crop" in your question, I'm not sure if you didn't already know this, but what do you want to know then?

To use cropping, here is an example:

//Your Image
$imgSrc = "image.jpg";

//getting the image dimensions
list($width, $height) = getimagesize($imgSrc);

//saving the image into memory (for manipulation with GD Library)
$myImage = imagecreatefromjpeg($imgSrc);

// calculating the part of the image to use for thumbnail
if ($width > $height) {
  $y = 0;
  $x = ($width - $height) / 2;
  $smallestSide = $height;
} else {
  $x = 0;
  $y = ($height - $width) / 2;
  $smallestSide = $width;
}

// copying the part into thumbnail
$thumbSize = 100;
$thumb = imagecreatetruecolor($thumbSize, $thumbSize);
imagecopyresampled($thumb, $myImage, 0, 0, $x, $y, $thumbSize, $thumbSize, $smallestSide, $smallestSide);

//final output
header('Content-type: image/jpeg');
imagejpeg($thumb);

Answer 3

I like using GDLib to fiddle with images, it's fantastically easy to work with also. There are lots of blog posts and tutorials out there. I would recommend using a class for it or similar though, as taking care of all the variations in the image can be very time consuming.