Dimensionar as imagens com o PHP, suportar o PNG, O JPG
estou a usar esta classe:
class ImgResizer {
function ImgResizer($originalFile = '$newName') {
$this -> originalFile = $originalFile;
}
function resize($newWidth, $targetFile) {
if (empty($newWidth) || empty($targetFile)) {
return false;
}
$src = imagecreatefromjpeg($this -> originalFile);
list($width, $height) = getimagesize($this -> originalFile);
$newHeight = ($height / $width) * $newWidth;
$tmp = imagecreatetruecolor($newWidth, $newHeight);
imagecopyresampled($tmp, $src, 0, 0, 0, 0, $newWidth, $newHeight, $width, $height);
if (file_exists($targetFile)) {
unlink($targetFile);
}
imagejpeg($tmp, $targetFile, 95);
}
}
O que funciona perfeitamente, mas falha com o png, cria uma imagem a preto redimensionado.
Existe uma maneira de ajustar esta classe para suportar imagens png?
14
6 answers
function resize($newWidth, $targetFile, $originalFile) {
$info = getimagesize($originalFile);
$mime = $info['mime'];
switch ($mime) {
case 'image/jpeg':
$image_create_func = 'imagecreatefromjpeg';
$image_save_func = 'imagejpeg';
$new_image_ext = 'jpg';
break;
case 'image/png':
$image_create_func = 'imagecreatefrompng';
$image_save_func = 'imagepng';
$new_image_ext = 'png';
break;
case 'image/gif':
$image_create_func = 'imagecreatefromgif';
$image_save_func = 'imagegif';
$new_image_ext = 'gif';
break;
default:
throw new Exception('Unknown image type.');
}
$img = $image_create_func($originalFile);
list($width, $height) = getimagesize($originalFile);
$newHeight = ($height / $width) * $newWidth;
$tmp = imagecreatetruecolor($newWidth, $newHeight);
imagecopyresampled($tmp, $img, 0, 0, 0, 0, $newWidth, $newHeight, $width, $height);
if (file_exists($targetFile)) {
unlink($targetFile);
}
$image_save_func($tmp, "$targetFile.$new_image_ext");
}
35
Author: P. Galbraith, 2016-02-24 17:13:51
Sei que estou atrasado para o espectáculo, mas isto pode ajudar outros que precisam da mesma coisa.
Eu escrevi uma aula que vai fazer exatamente isso e é agradável e fácil de usar. Chama-se
mágico de imagem PHP
mágico de imagem PHP
$magicianObj = new imageLib('racecar.jpg');
$magicianObj -> resizeImage(100, 200);
$magicianObj -> saveImage('racecar_convertd.png', 100);
Suporta ler e escrever (incluindo converter) os seguintes formatos
- jpg
- png
- gif
- bmp
E pode ler apenas
- psd's
Exemplo
// Include PHP Image Magician library require_once('php_image_magician.php'); // Open JPG image $magicianObj = new imageLib('racecar.jpg'); // Resize to best fit then crop $magicianObj -> resizeImage(100, 200, 'crop'); // Save resized image as a PNG $magicianObj -> saveImage('racecar_small.png');
9
Author: Jarrod, 2018-02-16 19:05:42
Podes tentar isto. Atualmente, está assumindo que a imagem será sempre um jpeg. Isto permitir-lhe-á carregar um jpeg, png ou gif. Ainda não testei, mas deve funcionar.
function resize($newWidth, $targetFile) {
if (empty($newWidth) || empty($targetFile)) {
return false;
}
$fileHandle = @fopen($this->originalFile, 'r');
//error loading file
if(!$fileHandle) {
return false;
}
$src = imagecreatefromstring(stream_get_contents($fileHandle));
fclose($fileHandle);
//error with loading file as image resource
if(!$src) {
return false;
}
//get image size from $src handle
list($width, $height) = array(imagesx($src), imagesy($src));
$newHeight = ($height / $width) * $newWidth;
$tmp = imagecreatetruecolor($newWidth, $newHeight);
imagecopyresampled($tmp, $src, 0, 0, 0, 0, $newWidth, $newHeight, $width, $height);
//allow transparency for pngs
imagealphablending($tmp, false);
imagesavealpha($tmp, true);
if (file_exists($targetFile)) {
unlink($targetFile);
}
//handle different image types.
//imagepng() uses quality 0-9
switch(strtolower(pathinfo($this->originalFile, PATHINFO_EXTENSION))) {
case 'jpg':
case 'jpeg':
imagejpeg($tmp, $targetFile, 95);
break;
case 'png':
imagepng($tmp, $targetFile, 8.5);
break;
case 'gif':
imagegif($tmp, $targetFile);
break;
}
//destroy image resources
imagedestroy($tmp);
imagedestroy($src);
}
5
Author: Austin Brunkhorst, 2014-02-27 13:47:05
Peguei na versão do P. Galbraith, Corrigi os erros e alterei-a para redimensionar por área (largura x altura). Para mim, eu queria redimensionar imagens que são muito grandes.
function resizeByArea($originalFile,$targetFile){
$newArea = 375000; //a little more than 720 x 480
list($width,$height,$type) = getimagesize($originalFile);
$area = $width * $height;
if($area > $newArea){
if($width > $height){ $big = $width; $small = $height; }
if($width < $height){ $big = $height; $small = $width; }
$ratio = $big / $small;
$newSmall = sqrt(($newArea*$small)/$big);
$newBig = $ratio*$newSmall;
if($width > $height){ $newWidth = round($newBig, 0); $newHeight = round($newSmall, 0); }
if($width < $height){ $newWidth = round($newSmall, 0); $newHeight = round($newBig, 0); }
}
switch ($type) {
case '2':
$image_create_func = 'imagecreatefromjpeg';
$image_save_func = 'imagejpeg';
$new_image_ext = '.jpg';
break;
case '3':
$image_create_func = 'imagecreatefrompng';
// $image_save_func = 'imagepng';
// The quality is too high with "imagepng"
// but you need it if you want to allow transparency
$image_save_func = 'imagejpeg';
$new_image_ext = '.png';
break;
case '1':
$image_create_func = 'imagecreatefromgif';
$image_save_func = 'imagegif';
$new_image_ext = '.gif';
break;
default:
throw Exception('Unknown image type.');
}
$img = $image_create_func($originalFile);
$tmp = imagecreatetruecolor($newWidth,$newHeight);
imagecopyresampled( $tmp, $img, 0, 0, 0, 0,$newWidth,$newHeight, $width, $height );
ob_start();
$image_save_func($tmp);
$i = ob_get_clean();
// if file exists, create a new one with "1" at the end
if (file_exists($targetFile.$new_image_ext)){
$targetFile = $targetFile."1".$new_image_ext;
}
else{
$targetFile = $targetFile.$new_image_ext;
}
$fp = fopen ($targetFile,'w');
fwrite ($fp, $i);
fclose ($fp);
unlink($originalFile);
}
Se quiser permitir transparência, verifique isto: http://www.akemapa.com/2008/07/10/php-gd-resize-transparent-image-png-gif/
Testei a função, funciona bem! 1
Author: pmrotule, 2013-03-01 18:13:55
Tente este e usando este Você também pode salvar a sua imagem para um caminho específico.
function resize($file, $imgpath, $width, $height){
/* Get original image x y*/
list($w, $h) = getimagesize($file['tmp_name']);
/* calculate new image size with ratio */
$ratio = max($width/$w, $height/$h);
$h = ceil($height / $ratio);
$x = ($w - $width / $ratio) / 2;
$w = ceil($width / $ratio);
/* new file name */
$path = $imgpath;
/* read binary data from image file */
$imgString = file_get_contents($file['tmp_name']);
/* create image from string */
$image = imagecreatefromstring($imgString);
$tmp = imagecreatetruecolor($width, $height);
imagecopyresampled($tmp, $image, 0, 0, $x, 0, $width, $height, $w, $h);
/* Save image */
switch ($file['type']) {
case 'image/jpeg':
imagejpeg($tmp, $path, 100);
break;
case 'image/png':
imagepng($tmp, $path, 0);
break;
case 'image/gif':
imagegif($tmp, $path);
break;
default:
//exit;
break;
}
return $path;
/* cleanup memory */
imagedestroy($image);
imagedestroy($tmp);
}
Agora você precisa chamar esta função ao gravar a imagem como tal...
<?php
//$imgpath = "Where you want to save your image";
resize($_FILES["image"], $imgpath, 340, 340);
?>
0
Author: Hardik, 2015-02-11 15:02:44
A resposta aceite tem muitos erros aqui é que está fixa
<?php
function resize($newWidth, $targetFile, $originalFile) {
$info = getimagesize($originalFile);
$mime = $info['mime'];
switch ($mime) {
case 'image/jpeg':
$image_create_func = 'imagecreatefromjpeg';
$image_save_func = 'imagejpeg';
$new_image_ext = 'jpg';
break;
case 'image/png':
$image_create_func = 'imagecreatefrompng';
$image_save_func = 'imagepng';
$new_image_ext = 'png';
break;
case 'image/gif':
$image_create_func = 'imagecreatefromgif';
$image_save_func = 'imagegif';
$new_image_ext = 'gif';
break;
default:
throw Exception('Unknown image type.');
}
$img = $image_create_func($originalFile);
list($width, $height) = getimagesize($originalFile);
$newHeight = ($height / $width) * $newWidth;
$tmp = imagecreatetruecolor($newWidth, $newHeight);
imagecopyresampled($tmp, $img, 0, 0, 0, 0, $newWidth, $newHeight, $width, $height);
if (file_exists($targetFile)) {
unlink($targetFile);
}
$image_save_func($tmp, "$targetFile.$new_image_ext");
}
$img=$_REQUEST['img'];
$id=$_REQUEST['id'];
// echo $img
resize(120, $_SERVER['DOCUMENT_ROOT'] ."/images/$id",$_SERVER['DOCUMENT_ROOT'] ."/images/$img") ;
?>
-1
Author: bdaz, 2013-12-25 07:00:34