如何使用php调整png和gif图像的大小并存储透明背景？
这是我的代码
将图片大小调整为200x200 px并上传到PIE目录。这很好用。
但是当与png或gif图像（透明bg）一起使用时。这将是bg变为黑色。如何在调整大小图像后写入透明的bg？
<form name="setup" method="post" ENCTYPE = "multipart/form-data" onsubmit="return checkform(this);">
<input type="file" name="offer_image_1" id="offer_image_1">
<input type="submit" name="submit" value="Next">
</form>
<?php
include("connect.php");
if(isset($_POST["submit"]))
{
##### This function will proportionally resize image #####
function normal_resize_image($source_thumbnail, $destination_thumbnail, $image_type_thumbnail, $max_size_thumbnail, $image_width_thumbnail, $image_height_thumbnail, $quality_thumbnail){
if($image_width_thumbnail <= 0 || $image_height_thumbnail <= 0){return false;} //return false if nothing to resize
//do not resize if image is smaller than max size
if($image_width_thumbnail <= $max_size_thumbnail && $image_height_thumbnail <= $max_size_thumbnail){
if(save_image($source_thumbnail, $destination_thumbnail, $image_type_thumbnail, $quality_thumbnail)){
return true;
}
}
//Construct a proportional size of new image
$image_scale_thumbnail = min($max_size_thumbnail/$image_width_thumbnail, $max_size_thumbnail/$image_height_thumbnail);
$new_width_thumbnail = ceil($image_scale_thumbnail * $image_width_thumbnail);
$new_height_thumbnail = ceil($image_scale_thumbnail * $image_height_thumbnail);
$new_canvas_thumbnail = imagecreatetruecolor( $new_width_thumbnail, $new_height_thumbnail ); //Create a new true color image
//Copy and resize part of an image with resampling
if(imagecopyresampled($new_canvas_thumbnail, $source_thumbnail, 0, 0, 0, 0, $new_width_thumbnail, $new_height_thumbnail, $image_width_thumbnail, $image_height_thumbnail)){
save_image($new_canvas_thumbnail, $destination_thumbnail, $image_type_thumbnail, $quality_thumbnail); //save resized image
}
return true;
}
##### This function corps image to create exact square, no matter what its original size! ######
function crop_image_square($source_thumbnail, $destination_thumbnail, $image_type_thumbnail, $square_size_thumbnail, $image_width_thumbnail, $image_height_thumbnail, $quality_thumbnail){
if($image_width_thumbnail <= 0 || $image_height_thumbnail <= 0){return false;} //return false if nothing to resize
if( $image_width_thumbnail > $image_height_thumbnail )
{
$y_offset_thumbnail = 0;
$x_offset_thumbnail = ($image_width_thumbnail - $image_height_thumbnail) / 2;
$s_size_thumbnail = $image_width_thumbnail - ($x_offset_thumbnail * 2);
}else{
$x_offset_thumbnail = 0;
$y_offset_thumbnail = ($image_height_thumbnail - $image_width_thumbnail) / 2;
$s_size_thumbnail = $image_height_thumbnail - ($y_offset_thumbnail * 2);
}
$new_canvas_thumbnail = imagecreatetruecolor( $square_size_thumbnail, $square_size_thumbnail); //Create a new true color image
//Copy and resize part of an image with resampling
if(imagecopyresampled($new_canvas_thumbnail, $source_thumbnail, 0, 0, $x_offset_thumbnail, $y_offset_thumbnail, $square_size_thumbnail, $square_size_thumbnail, $s_size_thumbnail, $s_size_thumbnail)){
save_image($new_canvas_thumbnail, $destination_thumbnail, $image_type_thumbnail, $quality_thumbnail);
}
return true;
}
##### Saves image resource to file #####
function save_image($source_thumbnail, $destination_thumbnail, $image_type_thumbnail, $quality_thumbnail){
switch(strtolower($image_type_thumbnail)){//determine mime type
case 'image/png':
imagepng($source_thumbnail, $destination_thumbnail); return true; //save png file
break;
case 'image/gif':
imagegif($source_thumbnail, $destination_thumbnail); return true; //save gif file
break;
case 'image/jpeg': case 'image/pjpeg':
imagejpeg($source_thumbnail, $destination_thumbnail, $quality_thumbnail); return true; //save jpeg file
break;
default: return false;
}
}
$thumb_square_size_thumbnail = 200; //Thumbnails will be cropped to 200x200 pixels
$max_image_size_thumbnail = 5000; //Maximum image size (height and width)
$thumb_prefix_thumbnail = "img_"; //Normal thumb Prefix
$destination_folder_thumbnail = 'PIE/'; //upload directory ends with / (slash)
$jpeg_quality_thumbnail = 100; //jpeg quality
// Start ตรวจสอบ และ upload รูปภาพ //
//uploaded file info we need to proceed
$image_type_thumbnail_check = $_FILES['offer_image_1']['type']; //file type
$image_name_thumbnail = $_FILES['offer_image_1']['name']; //file name
$image_size_thumbnail = $_FILES['offer_image_1']['size']; //file size
$image_temp_thumbnail = $_FILES['offer_image_1']['tmp_name']; //file temp
$image_size_info_thumbnail = getimagesize($image_temp_thumbnail); //get image size
if($image_size_info_thumbnail)
{
$image_width_thumbnail = $image_size_info_thumbnail[0]; //image width
$image_height_thumbnail = $image_size_info_thumbnail[1]; //image height
$image_type_thumbnail = $image_size_info_thumbnail['mime']; //image type
//switch statement below checks allowed image type
//as well as creates new image from given file
switch($image_type_thumbnail)
{
case 'image/png':
$image_res_thumbnail = imagecreatefrompng($image_temp_thumbnail); break;
case 'image/gif':
$image_res_thumbnail = imagecreatefromgif($image_temp_thumbnail); break;
case 'image/jpeg': case 'image/pjpeg':
$image_res_thumbnail = imagecreatefromjpeg($image_temp_thumbnail); break;
default:
$image_res_thumbnail = false;
}
if($image_res_thumbnail)
{
//Get file extension and name to construct new file name
$image_info_thumbnail = pathinfo($image_name_thumbnail);
$image_extension_thumbnail = strtolower($image_info_thumbnail["extension"]); //image extension
$image_name_only_thumbnail = strtolower($image_info_thumbnail["filename"]);//file name only, no extension
//create a random name for new image (Eg: fileName_293749.jpg);
$new_file_name_thumbnail = 'xxxxxxxxx.'.$image_extension_thumbnail;
//folder path to save resized images and thumbnails
$thumb_save_folder_thumbnail = $destination_folder_thumbnail . $thumb_prefix_thumbnail . $new_file_name_thumbnail;
$image_save_folder_thumbnail = $destination_folder_thumbnail . $new_file_name_thumbnail;
//call normal_resize_image() function to proportionally resize image
if(crop_image_square($image_res_thumbnail, $thumb_save_folder_thumbnail, $image_type_thumbnail, $thumb_square_size_thumbnail, $image_width_thumbnail, $image_height_thumbnail, $jpeg_quality_thumbnail))
{
//echo "Success";
}
imagedestroy($image_res_thumbnail); //freeup memory
}
$image_path = $destination_folder_thumbnail.''.$thumb_prefix_thumbnail.''.$new_file_name_thumbnail;
}
}
?>
答案 0 :(得分：0)
我用图书馆来处理图像。就像创建照片库，转换，调整大小和处理上传的图像一样，应用效果，添加标签，水印和反射以及其他图像编辑功能.... documentation
答案 1 :(得分：0)
您可以直接对图像使用html img标签，也可以通过javascript操作它的样式......
<div class="row">
<div class="col-md-4">
<h4 class="heading">Upload Patient's Photo :-</h4>
</div>
<div class="col-md-4">
<input type="file" class="form-control" name="patientpic" id="patientpic" onchange="readURL(this)"/>
</div>
</div>
<script>
function readURL(input) {
if (input.files && input.files[0]) {
var reader = new FileReader();
reader.onload = function (e)
{
$('#patientimg').attr('src', e.target.result);
}
reader.readAsDataURL(input.files[0]);
}
}
</script>
</div>
<div class="col-md-2 col-sm-12">
<div class="thumbnail">
<img src="#" alt="..." class="img-responsive img-rounded" id="patientimg" style="height:200px;width:200px;background-color:transparent;">
</div>
</div>
同样这也可以通过php在php string中使用这段代码来完成。