PHP GD如何循环裁剪3张正方形图像并合并为1张保持透明度的图像
PHP GD How to circular crop 3 square images and merge into 1 image maintaining transparency
我有 2 个源图像，我想：
- 对每个图像做一个圆形裁剪，圆的外面是透明的
- Merge/copy 所有图像回到目标透明图像。
我试过many examples，但似乎无法保持最终图像的透明度。
我正在努力实现这样的目标：
这是我得到的输出示例：
这是我的 circle_crop 函数：
function create_circle( $img_path ) {
// Attribution: by NerdsOfTech
// Step 1 - Start with image as layer 1 (canvas).
if (! $img1 = $this->imageCreateFromAny( $img_path )) {
return FALSE;
}
$x=imagesx($img1);
$y=imagesy($img1);
// Step 2 - Create a blank image.
$img2 = imagecreatetruecolor($x, $y);
$bg = imagecolorallocate($img2, 255,0,255, 127); // wierdo pink background
// $bg = imagecolorallocate($img2, 0, 0, 0, 127 ); // white background
imagefill($img2, 0, 0, $bg);
imagecolortransparent($img2, $bg);
// Step 3 - Create the ellipse OR circle mask.
$e = imagecolorallocate($img2, 255, 255, 255); // black mask color
// Draw a ellipse mask
imagefilledellipse ($img2, ($x/2), ($y/2), $x, $y, $e);
// OR
// Draw a circle mask
// $r = $x <= $y ? $x : $y; // use smallest side as radius & center shape
// imagefilledellipse ($img2, ($x/2), ($y/2), $r, $r, $e);
// Step 4 - Make shape color transparent
imagecolortransparent($img2, $e);
// Step 5 - Merge the mask into canvas with 100 percent opacity
imagecopymerge($img1, $img2, 0, 0, 0, 0, $x, $y, 100);
// Step 6 - Make outside border color around circle transparent
imagecolortransparent($img1, $bg);
/* Clean up memory */
imagedestroy($img2);
return $img1;
}
这是我传入图像数组 URL 并循环调用 circle_crop 函数以 return 裁剪图像并将其合并到目标图像的代码。
function generate_collage( $img_name_path_array, $effect = 'POLAROID' ) {
$base_img_width = 800;
$base_img_height = 650;
if (empty($img_name_path_array)) {
error_log('Image name_path_array is blank?'.PHP_EOL);
return FALSE;
}
$effect = strtoupper($effect);
/* Create canvas */
$collage_img = imagecreatetruecolor($base_img_width, $base_img_height);
imagealphablending($collage_img, false);
imagesavealpha($collage_img,true);
/* Create alpha channel for transparent layer */
$trans_col=imagecolorallocatealpha($collage_img,255,255,255, 127);
/* Create overlapping transparent layer */
imagefilledrectangle($collage_img,0,0,$base_img_width,$base_img_height,$trans_col);
/* Continue to keep layers transparent */
imagealphablending($collage_img,true);
$size_reduction = .80;
$start_size = 100;
foreach ($img_name_path_array as $image_array ) {
$img_text = $image_array[0];
$img_path = $image_array[1];
if (! empty($img_path)) {
switch ($effect) {
/* Add other collage image effects here */
case 'POLAROID' : {
$temp_img = $this->create_polaroid($img_path, $img_text, TRUE);
break;
}
case 'CIRCLES' : {
// $temp_img = $this->circle_crop($img_path);
$temp_img = $this->create_circle($img_path);
break;
}
default : {
/* Default to polaroid for now */
$temp_img = $this->create_polaroid($img_path, $img_text, TRUE);
break;
}
}
if ($temp_img) {
/* Get original height and width paramaters */
$source_w = imagesx($temp_img);
$source_h = imagesy($temp_img);
/* Randomise X and Y coordinates */
$random_x_pos = rand(0, (int) ($base_img_width * .66));
$random_y_pos = rand(0, (int) ($base_img_height * .3));
/* Randomise image size */
$start_size = ($start_size * $size_reduction);
$random_img_size_ratio = $start_size / 100;
/* Add generated image to base collage image */
imagecopyresampled($collage_img, $temp_img, $random_x_pos, $random_y_pos, 0, 0, ($base_img_width * $random_img_size_ratio), ($base_img_height * $random_img_size_ratio), $source_w, $source_h);
imagecolortransparent($collage_img, $trans_col);
/* Keep transparent when saving */
imagesavealpha($collage_img,true);
/* Memory clean up */
imagedestroy($temp_img);
// break;
}
}
}
/* Now display PNG to browser */
$this->show_png_from_image_object($collage_img);
}
这是我的显示函数：
function show_png_from_image_object( $img_obj ) {
header ( 'Content-Type: image/png' );
/* Display PNG with max compression */
imagepng ( $img_obj, NULL, 9, PNG_ALL_FILTERS);
imagedestroy ( $img_obj );
}
我已经拔头发 2 天了，如果有任何指点，我们将不胜感激。
谢谢杰森。
我已经编写了以下内容 class 来处理所有必需的图像处理：
class Img
{
public $img;
public $transparent;
public $width;
public $height;
public function __construct($img = null)
{
if (!empty($img)) {
$this->img = imagecreatefrompng($img);
$this->width = imagesx($this->img);
$this->height = imagesy($this->img);
$this->setTransparentColour();
}
}
public function create($width, $height, $transparent)
{
$this->img = imagecreatetruecolor($width, $height);
$this->width = $width;
$this->height =$height;
$this->setTransparentColour();
if (true === $transparent) {
imagefill($this->img, 0, 0, $this->transparent);
}
}
public function setTransparentColour($red = 255, $green = 0, $blue = 255)
{
$this->transparent = imagecolorallocate($this->img, $red, $green, $blue);
imagecolortransparent($this->img, $this->transparent);
}
public function circleCrop()
{
$mask = imagecreatetruecolor($this->width, $this->height);
$black = imagecolorallocate($mask, 0, 0, 0);
$magenta = imagecolorallocate($mask, 255, 0, 255);
imagefill($mask, 0, 0, $magenta);
imagefilledellipse(
$mask,
($this->width / 2),
($this->height / 2),
$this->width,
$this->height,
$black
);
imagecolortransparent($mask, $black);
imagecopymerge($this->img, $mask, 0, 0, 0, 0, $this->width, $this->height, 100);
imagedestroy($mask);
}
public function merge(Img $in, $dst_x = 0, $dst_y = 0)
{
imagecopymerge(
$this->img,
$in->img,
$dst_x,
$dst_y,
0,
0,
$in->width,
$in->height,
100
);
}
public function render()
{
header('Content-type: image/png');
imagepng($this->img);
}
}
正如所写，class 仅适用于 PNG 文件，但如果需要，您应该能够很容易地对其进行修改。
示例 class 用法：
// create a transparent base image that we will merge the cropped images into.
$img = new Img();
$img->create(400, 400, true);
// first image; crop and merge with base.
$img2 = new Img('./crop_1.png');
$img2->circleCrop();
$img->merge($img2, 50, 50);
// second image; crop and merge with base.
$img3 = new Img('./crop_2.png');
$img3->circleCrop();
$img->merge($img3, 25, 200);
$img->render();
这将导致下图（当然，嵌入此处时无法看到透明度，因此请尝试单独打开图像）：
我使用了这两个源图像：
您可以使用 ImageArtist，它是 GD 包装器创建的，用于使用 php
使图像处理异常简单
$overlay = new Overlay(720, 480, new Color(34,34,36));
$w = $overlay->getWidth();
$h = $overlay->getHeight();
$mi = new CircularShape("./mi.jpg");
$mi->scale(21);
$mi->setAxises(60,60);
$mi->build();
$mali = new CircularShape("./mali.jpg");
$mali->scale(60);
$mali->setAxises(140,140);
$mali->build();
$bach = new CircularShape("./har.jpeg");
$bach->scale(40);
$bach->setAxises(80,80);
$bach->build();
$borderd = new CircularShape(new Overlay($bach->getWidth()+10,$bach->getHeight()+10,new Color(255,255,255)));
$borderd->build();
$bach = $borderd->merge($bach,5,5);
$img = $overlay->merge($mi,$w/2 + 60,120);
$img->merge($mali,170,60);
$img->merge($bach,$w/2,200);
$img->dump(); //this just for demo, but you can use other methods to save this to disk
目前 ImageArtist 不支持边框，但如果您没有什么创意，可以改用叠加层。
这是上面代码的输出。
我有 2 个源图像，我想：
- 对每个图像做一个圆形裁剪，圆的外面是透明的
- Merge/copy 所有图像回到目标透明图像。
我试过many examples，但似乎无法保持最终图像的透明度。
我正在努力实现这样的目标：
这是我得到的输出示例：
这是我的 circle_crop 函数：
function create_circle( $img_path ) {
// Attribution: by NerdsOfTech
// Step 1 - Start with image as layer 1 (canvas).
if (! $img1 = $this->imageCreateFromAny( $img_path )) {
return FALSE;
}
$x=imagesx($img1);
$y=imagesy($img1);
// Step 2 - Create a blank image.
$img2 = imagecreatetruecolor($x, $y);
$bg = imagecolorallocate($img2, 255,0,255, 127); // wierdo pink background
// $bg = imagecolorallocate($img2, 0, 0, 0, 127 ); // white background
imagefill($img2, 0, 0, $bg);
imagecolortransparent($img2, $bg);
// Step 3 - Create the ellipse OR circle mask.
$e = imagecolorallocate($img2, 255, 255, 255); // black mask color
// Draw a ellipse mask
imagefilledellipse ($img2, ($x/2), ($y/2), $x, $y, $e);
// OR
// Draw a circle mask
// $r = $x <= $y ? $x : $y; // use smallest side as radius & center shape
// imagefilledellipse ($img2, ($x/2), ($y/2), $r, $r, $e);
// Step 4 - Make shape color transparent
imagecolortransparent($img2, $e);
// Step 5 - Merge the mask into canvas with 100 percent opacity
imagecopymerge($img1, $img2, 0, 0, 0, 0, $x, $y, 100);
// Step 6 - Make outside border color around circle transparent
imagecolortransparent($img1, $bg);
/* Clean up memory */
imagedestroy($img2);
return $img1;
}
这是我传入图像数组 URL 并循环调用 circle_crop 函数以 return 裁剪图像并将其合并到目标图像的代码。
function generate_collage( $img_name_path_array, $effect = 'POLAROID' ) {
$base_img_width = 800;
$base_img_height = 650;
if (empty($img_name_path_array)) {
error_log('Image name_path_array is blank?'.PHP_EOL);
return FALSE;
}
$effect = strtoupper($effect);
/* Create canvas */
$collage_img = imagecreatetruecolor($base_img_width, $base_img_height);
imagealphablending($collage_img, false);
imagesavealpha($collage_img,true);
/* Create alpha channel for transparent layer */
$trans_col=imagecolorallocatealpha($collage_img,255,255,255, 127);
/* Create overlapping transparent layer */
imagefilledrectangle($collage_img,0,0,$base_img_width,$base_img_height,$trans_col);
/* Continue to keep layers transparent */
imagealphablending($collage_img,true);
$size_reduction = .80;
$start_size = 100;
foreach ($img_name_path_array as $image_array ) {
$img_text = $image_array[0];
$img_path = $image_array[1];
if (! empty($img_path)) {
switch ($effect) {
/* Add other collage image effects here */
case 'POLAROID' : {
$temp_img = $this->create_polaroid($img_path, $img_text, TRUE);
break;
}
case 'CIRCLES' : {
// $temp_img = $this->circle_crop($img_path);
$temp_img = $this->create_circle($img_path);
break;
}
default : {
/* Default to polaroid for now */
$temp_img = $this->create_polaroid($img_path, $img_text, TRUE);
break;
}
}
if ($temp_img) {
/* Get original height and width paramaters */
$source_w = imagesx($temp_img);
$source_h = imagesy($temp_img);
/* Randomise X and Y coordinates */
$random_x_pos = rand(0, (int) ($base_img_width * .66));
$random_y_pos = rand(0, (int) ($base_img_height * .3));
/* Randomise image size */
$start_size = ($start_size * $size_reduction);
$random_img_size_ratio = $start_size / 100;
/* Add generated image to base collage image */
imagecopyresampled($collage_img, $temp_img, $random_x_pos, $random_y_pos, 0, 0, ($base_img_width * $random_img_size_ratio), ($base_img_height * $random_img_size_ratio), $source_w, $source_h);
imagecolortransparent($collage_img, $trans_col);
/* Keep transparent when saving */
imagesavealpha($collage_img,true);
/* Memory clean up */
imagedestroy($temp_img);
// break;
}
}
}
/* Now display PNG to browser */
$this->show_png_from_image_object($collage_img);
}
这是我的显示函数：
function show_png_from_image_object( $img_obj ) {
header ( 'Content-Type: image/png' );
/* Display PNG with max compression */
imagepng ( $img_obj, NULL, 9, PNG_ALL_FILTERS);
imagedestroy ( $img_obj );
}
我已经拔头发 2 天了，如果有任何指点，我们将不胜感激。
谢谢杰森。
我已经编写了以下内容 class 来处理所有必需的图像处理：
class Img
{
public $img;
public $transparent;
public $width;
public $height;
public function __construct($img = null)
{
if (!empty($img)) {
$this->img = imagecreatefrompng($img);
$this->width = imagesx($this->img);
$this->height = imagesy($this->img);
$this->setTransparentColour();
}
}
public function create($width, $height, $transparent)
{
$this->img = imagecreatetruecolor($width, $height);
$this->width = $width;
$this->height =$height;
$this->setTransparentColour();
if (true === $transparent) {
imagefill($this->img, 0, 0, $this->transparent);
}
}
public function setTransparentColour($red = 255, $green = 0, $blue = 255)
{
$this->transparent = imagecolorallocate($this->img, $red, $green, $blue);
imagecolortransparent($this->img, $this->transparent);
}
public function circleCrop()
{
$mask = imagecreatetruecolor($this->width, $this->height);
$black = imagecolorallocate($mask, 0, 0, 0);
$magenta = imagecolorallocate($mask, 255, 0, 255);
imagefill($mask, 0, 0, $magenta);
imagefilledellipse(
$mask,
($this->width / 2),
($this->height / 2),
$this->width,
$this->height,
$black
);
imagecolortransparent($mask, $black);
imagecopymerge($this->img, $mask, 0, 0, 0, 0, $this->width, $this->height, 100);
imagedestroy($mask);
}
public function merge(Img $in, $dst_x = 0, $dst_y = 0)
{
imagecopymerge(
$this->img,
$in->img,
$dst_x,
$dst_y,
0,
0,
$in->width,
$in->height,
100
);
}
public function render()
{
header('Content-type: image/png');
imagepng($this->img);
}
}
正如所写，class 仅适用于 PNG 文件，但如果需要，您应该能够很容易地对其进行修改。
示例 class 用法：
// create a transparent base image that we will merge the cropped images into.
$img = new Img();
$img->create(400, 400, true);
// first image; crop and merge with base.
$img2 = new Img('./crop_1.png');
$img2->circleCrop();
$img->merge($img2, 50, 50);
// second image; crop and merge with base.
$img3 = new Img('./crop_2.png');
$img3->circleCrop();
$img->merge($img3, 25, 200);
$img->render();
这将导致下图（当然，嵌入此处时无法看到透明度，因此请尝试单独打开图像）：
我使用了这两个源图像：
您可以使用 ImageArtist，它是 GD 包装器创建的，用于使用 php
使图像处理异常简单$overlay = new Overlay(720, 480, new Color(34,34,36));
$w = $overlay->getWidth();
$h = $overlay->getHeight();
$mi = new CircularShape("./mi.jpg");
$mi->scale(21);
$mi->setAxises(60,60);
$mi->build();
$mali = new CircularShape("./mali.jpg");
$mali->scale(60);
$mali->setAxises(140,140);
$mali->build();
$bach = new CircularShape("./har.jpeg");
$bach->scale(40);
$bach->setAxises(80,80);
$bach->build();
$borderd = new CircularShape(new Overlay($bach->getWidth()+10,$bach->getHeight()+10,new Color(255,255,255)));
$borderd->build();
$bach = $borderd->merge($bach,5,5);
$img = $overlay->merge($mi,$w/2 + 60,120);
$img->merge($mali,170,60);
$img->merge($bach,$w/2,200);
$img->dump(); //this just for demo, but you can use other methods to save this to disk
目前 ImageArtist 不支持边框，但如果您没有什么创意，可以改用叠加层。 这是上面代码的输出。