我正在尝试制作缩略图。并且php功能有效。我用它做了缩略图。但是，某些文件不起作用。我已经缩小了问题范围，但现在陷入了困境。任何帮助将不胜感激。
图片可以在http://www.pspsigma.com/image_test.php找到。左边的图片不起作用。右边的那个会。两者都是.jpg。两者最初都是通过表单上传的，但是已经针对堆栈溢出进行了更改，因此该函数可以在没有表单的情况下工作。
html是一个简单的脚本，对此.php文件具有文件输入设置操作
php：
<?php
$the_name= $_FILES['userfile']['name'];
$tmpname = $_FILES['userfile']['tmp_name'];
$size="1000";
$save_dir="images/thumbs/";
$save_name=$the_name;
$maxisheight= "100";
function img_resize( $tmpname, $size, $save_dir, $save_name, $maxisheight)
{
$save_dir .= ( substr($save_dir,-1) != "/") ? "/" : "";
$gis = getimagesize($tmpname);
$type = $gis[2];
switch($type)
{
case "1": $imorig = imagecreatefromgif($tmpname); break;
case "2": $imorig = imagecreatefromjpeg($tmpname);break;
case "3": $imorig = imagecreatefrompng($tmpname); break;
default: $imorig = imagecreatefromjpeg($tmpname);
}
//check if imorig is set
if (!isset($imorig)) {
echo " imorig is not set, ";
}
//I tried setting $x and $y from the width and height of the original file. Still didn't work.
//although the variables were set.
//this makes me think the problem is with the imagecreatefromjpeg function.
list($width, $height, $type, $attr) = getimagesize($tmpname);
echo "getimagesize width= " . $width . ", ";
echo "getimagesize height= " . $height . ", ";
//possible solution, didn't work
//$x = $width;
//$y = $height;
//This is the problem
$x = imagesx($imorig);
$y = imagesy($imorig);
//check that x and y are set
if (!isset($x) && !isset($y)) {
echo" x and y are not set,";
}
elseif (!isset($x)) {
echo" x is not set";
}
elseif (!isset($y)) {
echo" y is not set";
}
else {
echo "|x= " . $x . " |";
echo "|y= " . $y . " |";
}
$woh = (!$maxisheight)? $gis[0] : $gis[1] ;
if($woh <= $size)
{
$aw = $x;
$ah = $y;
}
else
{
if(!$maxisheight){
$aw = $size;
$ah = $size * $y / $x;
} else {
$aw = $size * $x / $y;
$ah = $size;
}
}
$im = imagecreatetruecolor($aw,$ah);
if (!$im) {
echo " failure: no im variable. ";
}
else {
if (imagecopyresampled($im,$imorig , 0,0,0,0,$aw,$ah,$x,$y)) {
if (!imagejpeg($im, $save_dir.$save_name)) {
echo "failure";}
else {
echo "success";}
}
else {
echo" didn't copy resampled";
}
}
}
img_resize( $tmpname, $size, $save_dir, $save_name, $maxisheight);
?>
如果我选择rush vader.jpg文件并通过此功能。它回显了x和y的设置，显示它们的值和成功。
如果我选择calm.jpg，它将回应“失败：没有变量”。并且$ x和$ y变量没有值。如果我从getimagesize（$ tmp_name）中为x和y变量赋值，则它回应“没有复制重新采样”。
这是实际图像的问题吗？或者有什么方法可以更改代码，以便每个图像都有效？
谢谢!!!
更新
我回应了每个变量，看看是否有什么东西掉了。问题似乎是在类型中。类型输出为6，从我发现的php手册评论是bmp。
如果扩展名为.jpg，我不明白这是怎么回事......如果是这样的话。是一种更改类型的方法，使其成为.jpg，.png或.gif？
答案 0 :(得分：2)
图像calm.jpg中的类型是6，这是一个bmp。因此，imagecreatefrom ...将无效，$ imorig为NULL。通过添加一个名为imagecreatefrombmp的php手册中带有标签6的函数。该函数完美无缺。
添加到文件中：
function imagecreatefrombmp($p_sFile) {
// Load the image into a string
$file = fopen($p_sFile,"rb");
$read = fread($file,10);
while(!feof($file)&&($read<>""))
$read .= fread($file,1024);
$temp = unpack("H*",$read);
$hex = $temp[1];
$header = substr($hex,0,108);
// Process the header
// Structure: http://www.fastgraph.com/help/bmp_header_format.html
if (substr($header,0,4)=="424d")
{
// Cut it in parts of 2 bytes
$header_parts = str_split($header,2);
// Get the width 4 bytes
$width = hexdec($header_parts[19].$header_parts[18]);
// Get the height 4 bytes
$height = hexdec($header_parts[23].$header_parts[22]);
// Get the horz. resolution in pixel per meter, 4 bytes
$dpix = hexdec($header_parts[39]. $header_parts[38]) * 0.0254;
// Get the vert. resolution in pixel per meter, 4 bytes
$dpiy = hexdec($header_parts[43]. $header_parts[42]) * 0.0254;
// Unset the header params
unset($header_parts);
}
// Define starting X and Y
$x = 0;
$y = 1;
// Create newimage
$image = imagecreatetruecolor($width,$height);
// Grab the body from the image
$body = substr($hex,108);
// Calculate if padding at the end-line is needed
// Divided by two to keep overview.
// 1 byte = 2 HEX-chars
$body_size = (strlen($body)/2);
$header_size = ($width*$height);
// Use end-line padding? Only when needed
$usePadding = ($body_size>($header_size*3)+4);
// Using a for-loop with index-calculation instaid of str_split to avoid large memory consumption
// Calculate the next DWORD-position in the body
for ($i=0;$i<$body_size;$i+=3)
{
// Calculate line-ending and padding
if ($x>=$width)
{
// If padding needed, ignore image-padding
// Shift i to the ending of the current 32-bit-block
if ($usePadding)
$i += $width%4;
// Reset horizontal position
$x = 0;
// Raise the height-position (bottom-up)
$y++;
// Reached the image-height? Break the for-loop
if ($y>$height)
break;
}
// Calculation of the RGB-pixel (defined as BGR in image-data)
// Define $i_pos as absolute position in the body
$i_pos = $i*2;
$r = hexdec($body[$i_pos+4].$body[$i_pos+5]);
$g = hexdec($body[$i_pos+2].$body[$i_pos+3]);
$b = hexdec($body[$i_pos].$body[$i_pos+1]);
// Calculate and draw the pixel
$color = imagecolorallocate($image,$r,$g,$b);
imagesetpixel($image,$x,$height-$y,$color);
// Raise the horizontal position
$x++;
}
// Unset the body / free the memory
unset($body);
// Return image-object
return ($image);
return ($dpix);
return ($dpiy);
}
添加：
case "6": $imorig = imagecreatefrombmp($tmpname); break;
case "15": $imorig = imagecreatefromwbmp($tmpname); break;
后
case "3": $imorig = imagecreatefrompng($tmpname); break;
测试。一切正常。谢谢大家！