How to reduce the image size without losing quality in PHP [closed]

Question

I am trying to develop an image-based web site. I am really confused about the best image type for faster page loading speeds and best compression practices. Please advise me on the best way to compress image sizes.

Adachi

Jpeg, gif and png images are already compressed. Can you clarify? – Boraginaceous

Answer 1

I'd go for jpeg. Read this post regarding image size reduction and after deciding on the technique, use ImageMagick

Hope this helps

Geraldine

Answer 2

If you are looking to reduce the size using coding itself, you can follow this code in php.

<?php 
function compress($source, $destination, $quality) {

    $info = getimagesize($source);

    if ($info['mime'] == 'image/jpeg') 
        $image = imagecreatefromjpeg($source);

    elseif ($info['mime'] == 'image/gif') 
        $image = imagecreatefromgif($source);

    elseif ($info['mime'] == 'image/png') 
        $image = imagecreatefrompng($source);

    imagejpeg($image, $destination, $quality);

    return $destination;
}

$source_img = 'source.jpg';
$destination_img = 'destination .jpg';

$d = compress($source_img, $destination_img, 90);
?>

---

$d = compress($source_img, $destination_img, 90);

This is just a php function that passes the source image ( i.e., $source_img ), destination image ( $destination_img ) and quality for the image that will take to compress ( i.e., 90 ).

$info = getimagesize($source);

The getimagesize() function is used to find the size of any given image file and return the dimensions along with the file type.

Rutharuthann

this function convert the source images to JPEG, ignore the gif animations and png transparency – Stephine

to overcome png transparency issue mentioned by @nikmauro, i used the imagepng instead of imagejpeg. using the imagejpeg for jpg files, ofcourse just modifying if statement to use appropriate function. however to save transparency i also had to add (before output/save) : imagealphablending($image, false); imagesavealpha($image, true); I also had to devide the $quality by 10 to work as imagepng does not go from 0 - 100 but rather 0 - 9 – Piracy

Good one there. But one thing that bothers me is why 90 for the compression? Is there a min value which when passed, the image is going to loose its "originality"? – Translucid

I'm not sure why but the image gets rotated when I use this code, how would I prevent this from happening. It always seems to be rotated 90 degrees anti clockwise. – Lucarne

sorted, I had to read the exif data from the original image and adjust accordingly. – Lucarne

Great! This is working but I'm getting 1 issue with it. While I'm uploading image thru the mobile camera then it sometimes rotates that image 90 degrees. What to do about that?? – Amathiste

Answer 3

You can resize and then use imagejpeg()

Don't pass 100 as the quality for imagejpeg() - anything over 90 is generally overkill and just gets you a bigger JPEG. For a thumbnail, try 75 and work downwards until the quality/size tradeoff is acceptable.

imagejpeg($tn, $save, 75);

Eckardt

how to move the resized image to particular folder? – Anting

Answer 4

well I think I have something interesting for you... https://github.com/whizzzkid/phpimageresize. I wrote it for the exact same purpose. Highly customizable, and does it in a great way.

Porky