Reputation: 73
Ok so I'm trying to resize an image using php. I do not have access to install plugins on the server I use at this time.
$originalimage
is the actual original image that I'm going to resize.
$width
is another parameter to define $original_width
. The same can be said for $height
and $original_height
.
$original_width = imagesx($originalimage);
$original_height = imagesy($originalimage);
$max_width = $thumbwidth;
$max_height = $thumbheight;
$width = $original_width;
$height = $original_height;
Using the pre-setup above I start to work on this one here. This works but no way to set a max height. For example I pass a max width as $thumbwidth
and max height as $thumbheight
and this will work as desired till I then try to go ahead and use an image that's higher than it is wide. (Portrait image.) It does not completely fail however it does fail to enforce a max height, rendering an image that can potentially be very high.
if ($width > $height) {
$newwidth = $thumbwidth;
$divisor = $width / $thumbwidth;
$newheight = floor( $height / $divisor);
} else {
$newheight = $thumbheight;
$divisor = $height / $thumbheight;
$newwidth = floor( $width / $divisor );
}
$image = imagecreatetruecolor( $newwidth, $newheight );
imagecopyresampled( $image, $originalimage, 0, 0, 0, 0, $newwidth, $newheight, $original_width, $original_height );
After trying to understand this and failing after a few hours I came up with the code below which I had gotten from php.net. As you can see there was a reason I set two sets of variables equal to each other in the pre-setup part of the code. Mostly because I can not comprehend calling $max_width
as $thumbwidth
in the second code segment.
This below works as well until you pass in a parameter though that is larger than the width or height of $originalimage
.
# taller
if ($height > $max_height) {
$width = ($max_height / $height) * $width;
$height = $max_height;
}
# wider
if ($width > $max_width) {
$height = ($max_width / $width) * $height;
$width = $max_width;
}
$image = imagecreatetruecolor( $width, $height );
imagecopyresampled( $image, $originalimage, 0, 0, 0, 0, $width, $height, $original_width, $original_height );
I'm sorry I can't find a way to do this on my own. As for this being a duplicate question, Most similar questions end up with "[Insert plugin name here] is better use that instead." I am asking specifically for an answer that does not use other plugins or javascript. (Besides GD which is pre-installed on my server.)
Before I end this question I will say that I am using imagejpeg($image);
so the use of HTML or CSS is completely forbidden.
Upvotes: 1
Views: 3110
Reputation: 337
I've had a very similar problem building the thumbs for a gallery page. I tried Daniel Nyamasyo solution above but just could not get past the "$img = imagecreatefromjpeg($sourcefile);" line without getting "Warning: imagecreatefromjpeg failed to open stream: HTTP request failed! HTTP/1.1 400 Bad Request" no matter what $sourcefile I fed it. I came up with this dirty method.
<?php
// Some variables
$thumb_width = 162; // The maximum values you want
$thumb_height = 122;
$thumb_pointer = 'thumbs'; // Put your output folder here which must exist
$img = imagecreatefromjpeg( $image_name);
$width = imagesx( $img );
$height = imagesy( $img );
if ($width>=$height)
{
// Now calculate thumbnail size
$new_width = $thumb_width;
$new_height = floor( $height * ($thumb_width / $width));
// The 'dirty' bit I found was needed for square or near square images
while ($new_height > $thumb_height)
{
$new_width = floor($new_width * 0.99);
$new_height = floor($new_height * 0.99);
}
}
else
{
$new_height = $thumb_height;
$new_width = floor($width * ($thumb_height / $height));
}
// Create a new temporary image
$tmp_img = imagecreatetruecolor( $new_width, $new_height );
// Copy and resize old image into new image
imagecopyresized( $tmp_img, $img, 0, 0, 0, 0, $new_width, $new_height, $width, $height );
// Save the thumbnail into a file
imagejpeg( $tmp_img, $thumb_pointer.'/'.$image_name);
?>
Upvotes: 0
Reputation: 4405
Here's a class I whipped up for a program I worked on. maybe it will help you?
<?php
class ImageHelper
{
/**
* @static
* @param $source string Path for source image
* @param $destination string Path for destination image to be placed
* @param $targetWidth int Width of the new image (in pixels)
* @param $targetHeight int Height of the new image (in pixels)
* @param $strict bool
*/
public static function createImage($source, $destination, $targetWidth, $targetHeight, $strict = false){
$dir = dirname($destination);
if(!is_dir($dir)){
mkdir($dir, 0770, true);
}
$fileContents = file_get_contents($source);
$image = imagecreatefromstring($fileContents);
$thumbnail = ImageHelper::resizeImage($image, $targetWidth, $targetHeight, $strict);
imagejpeg($thumbnail, $destination, 100);
imagedestroy($thumbnail);
imagedestroy($image);
}
/**
* Resize an image to the specified dimensions
* @param string $original Path to the original image
* @param int $targetWidth Width of the new image (in pixels)
* @param int $targetHeight Height of the new image (in pixels)
* @param bool $strict True to crop the picture to the specified dimensions, false for best fit
* @return bool|resource Returns the new image resource or false if the image was not resized.
*/
public static function resizeImage($original, $targetWidth, $targetHeight, $strict = false)
{
$originalWidth = imagesx($original);
$originalHeight = imagesy($original);
$widthRatio = $targetWidth / $originalWidth;
$heightRatio = $targetHeight / $originalHeight;
if(($widthRatio > 1 || $heightRatio > 1) && !$strict){
// don't scale up an image if either targets are greater than the original sizes and we aren't using a strict parameter
$dstHeight = $originalHeight;
$dstWidth = $originalWidth;
$srcHeight = $originalHeight;
$srcWidth = $originalWidth;
$srcX = 0;
$srcY = 0;
}elseif ($widthRatio > $heightRatio) {
// width is the constraining factor
if ($strict) {
$dstHeight = $targetHeight;
$dstWidth = $targetWidth;
$srcHeight = $originalHeight;
$srcWidth = $heightRatio * $targetWidth;
$srcX = floor(($originalWidth - $srcWidth) / 2);
$srcY = 0;
} else {
$dstHeight = ($originalHeight * $targetWidth) / $originalWidth;
$dstWidth = $targetWidth;
$srcHeight = $originalHeight;
$srcWidth = $originalWidth;
$srcX = 0;
$srcY = 0;
}
} else {
// height is the constraining factor
if ($strict) {
$dstHeight = $targetHeight;
$dstWidth = $targetWidth;
$srcHeight = $widthRatio * $targetHeight;
$srcWidth = $originalWidth;
$srcY = floor(($originalHeight - $srcHeight) / 2);
$srcX = 0;
} else {
$dstHeight = $targetHeight;
$dstWidth = ($originalWidth * $targetHeight) / $originalHeight;
$srcHeight = $originalHeight;
$srcWidth = $originalWidth;
$srcX = 0;
$srcY = 0;
}
}
$new = imagecreatetruecolor($dstWidth, $dstHeight);
if ($new === false) {
return false;
}
imagecopyresampled($new, $original, 0, 0, $srcX, $srcY, $dstWidth, $dstHeight, $srcWidth, $srcHeight);
return $new;
}
}
Upvotes: 1