图像颜色在 php 中随 imagecreate 改变

Question

我必须创建动态学生卡图像。添加将此图像对象放入学生个人资料照片中。但是，学生图像颜色发生了变化。

如何将学生头像放原色？

这是我的代码：

header("Content-Type: image/jpeg");
$im = @imagecreate(602, 980)
or die("Cannot Initialize new GD image stream");
$background_color = imagecolorallocate($im, 255, 255, 255);

$card_header = imagecreatefromjpeg('img/card/card-header.jpg');
imagecopy($im, $card_header, 0, 0, 0, 0, 602, 253);

$card_footer = imagecreatefromjpeg('img/card/card-footer.jpg');
imagecopy($im, $card_footer, 0, 834, 0, 0, 602, 146);

$student_photo = 'img/card/girls-profile.jpg'; //imagecreatefromjpeg($studentlist[0]->getCardPhoto());
// Get new sizes
list($width, $height) = getimagesize($student_photo);
$newwidth = 180;
$newheight = 220;

// Load
$thumb = imagecreatetruecolor($newwidth, $newheight);
$source = imagecreatefromjpeg($student_photo);

// Resize
imagecopyresized($thumb, $source, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);

imagecopy($im, $thumb, 220, 220, 0, 0, $newwidth, $newheight);

imagejpeg($im, "uploads/card/test.jpeg");
imagedestroy($im);

标题图片：

页脚图片：

个人资料图片：

这是我的输出图像：

Answer 1

主要问题是您的$im 也需要是真彩色图像。 其次，你必须实际填写你的背景。 您也可以跳过创建$thumb 并直接将大小复制到您的$im。

这是一个工作版本（我改变了你的路径以在我的机器上测试它）

<?php

    header('Content-Type: image/jpeg');

    $im = @imagecreatetruecolor(602, 980) // you want to create a truecolorimage here
    or die("Cannot Initialize new GD image stream");

    $background_color = imagecolorallocate($im, 255, 255, 255);
    imagefill($im, 0, 0, $background_color); // you have to actually use the allocated background color

    $card_header = imagecreatefromjpeg('card-header.jpg');
    imagecopy($im, $card_header, 0, 0, 0, 0, 602, 253);

    $card_footer = imagecreatefromjpeg('card-footer.jpg');
    imagecopy($im, $card_footer, 0, 834, 0, 0, 602, 146);

    $student_photo = 'girls-profile.jpg';

    // Get new sizes
    list($width, $height) = getimagesize($student_photo);
    $newwidth = 180;
    $newheight = 220;

    // Load
    //$thumb = imagecreatetruecolor($newwidth, $newheight); // you can skip allocating extra memory for a intermediate thumb
    $source = imagecreatefromjpeg($student_photo);

    // Resize
    imagecopyresized($im, $source, 220, 220, 0, 0, $newwidth, $newheight, $width, $height); // and copy the thumb directly

    imagejpeg($im);

    imagedestroy($im);
    // you should also destroy the other images
    imagedestroy($card_header);
    imagedestroy($card_footer);
    imagedestroy($source);

请记住，虽然您的个人资料图片当前会失真，但您可能不想确保个人资料图片始终具有正确的纵横比，或者您可能想要裁剪图像。更多详情请看这里：PHP crop image to fix width and height without losing dimension ratio