imagecreatefromstring
To get the horizontal and vertical resolution you could add some lines to the previous code of alexander. BMP stores the resolution in pixels per meter. To get it as pixels per inch (dpi) you have to multiply the value by 0.0254.
<?php
public function imagecreatefrombmp($p_sFile)
{
// ...
// ... insert after the lines where you get width and height...
// 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]. $header_parts[42]) * 0.0254;
// ... rest of the code...
return ($image, $dpix, $dpiy);
}
?>
imagecreatefromwbmp
(PHP 4 >= 4.0.1, PHP 5)
imagecreatefromwbmp — Create a new image from file or URL
설명
resource imagecreatefromwbmp
( string $filename
)
imagecreatefromwbmp() returns an image identifier representing the image obtained from the given filename.
Tip
fopen 래퍼를 활성화하면, 파일명으로 URL을 사용할 수 있습니다. 파일 이름을 지정하는 방법은 fopen()을 참고하십시오. 다양한 래퍼의 기능, 사용법, 제공하는 예약 정의 변수들에 대해서는 Supported Protocols and Wrappers를 참고하십시오.
인수
- filename
-
Path to the WBMP image.
반환값
Returns an image resource identifier on success, FALSE on errors.
예제
Example #1 Example to handle an error during loading of a WBMP
<?php
function LoadWBMP($imgname)
{
/* Attempt to open */
$im = @imagecreatefromwbmp($imgname);
/* See if it failed */
if(!$im)
{
/* Create a blank image */
$im = imagecreatetruecolor(150, 30);
$bgc = imagecolorallocate($im, 255, 255, 255);
$tc = imagecolorallocate($im, 0, 0, 0);
imagefilledrectangle($im, 0, 0, 150, 30, $bgc);
/* Output an error message */
imagestring($im, 1, 5, 5, 'Error loading ' . $imgname, $tc);
}
return $im;
}
header('Content-Type: image/vnd.wap.wbmp');
$img = LoadWBMP('bogus.image');
imagewbmp($img);
imagedestroy($img);
?>
주의
Note: WBMP 지원은 PHP를 GD-1.8 이상에서 컴파일해야 합니다.
Warning
PHP 4.3.0 이전의 윈도우 버전 PHP에서는 이 함수를 이용하여 원격 파일에 접근할 수 없습니다. allow_url_fopen을 활성화하여도 마찬가지입니다.
add a note
User Contributed Notes
imagecreatefromwbmp
php at webdecker dot de
28-Jan-2010 03:05
alexander at alexauto dot nl
08-Oct-2008 04:59
AeroX created a nice example, but it only works at specific imagesizes because bmp uses fully 32-bit lines. To prevent failures (different colors, pixel-shifting per line), the solution is to skip the padding, inserted after color-pixels on the line. His implementation did cutting the padding into the image-data, causing wrong colors, pixel-shifting per line and also an large memory-consumption.
I improved this script to the next implementation. The readability of a image is checked by a other function, so it doesn't take part in this script.
Suggestions? Please let me know.
<?php
public function imagecreatefrombmp($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].$header_parts[22]);
// Unset the header params
unset($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;
}
?>
d at bwdp dot org
14-Aug-2008 04:07
why has php not made a predefined function like imagecreatefrombmp yet? surely there's more demand for it than there is for the wbmp function
AeroX @ aerox-studios
11-May-2008 02:54
.bmp is just hex encoded RGB values.
All you need to do is open in binary mode and seperate the header from the body.
Decode the width and height from the header.
Then create the image pixel by pixel from the RGB values in the body.
function imagecreatefrombmp( $filename )
{
$file = fopen( $filename, "rb" );
$read = fread( $file, 10 );
while( !feof( $file ) && $read != "" )
{
$read .= fread( $file, 1024 );
}
$temp = unpack( "H*", $read );
$hex = $temp[1];
$header = substr( $hex, 0, 104 );
$body = str_split( substr( $hex, 108 ), 6 );
if( substr( $header, 0, 4 ) == "424d" )
{
$header = substr( $header, 4 );
// Remove some stuff?
$header = substr( $header, 32 );
// Get the width
$width = hexdec( substr( $header, 0, 2 ) );
// Remove some stuff?
$header = substr( $header, 8 );
// Get the height
$height = hexdec( substr( $header, 0, 2 ) );
unset( $header );
}
$x = 0;
$y = 1;
$image = imagecreatetruecolor( $width, $height );
foreach( $body as $rgb )
{
$r = hexdec( substr( $rgb, 4, 2 ) );
$g = hexdec( substr( $rgb, 2, 2 ) );
$b = hexdec( substr( $rgb, 0, 2 ) );
$color = imagecolorallocate( $image, $r, $g, $b );
imagesetpixel( $image, $x, $height-$y, $color );
$x++;
if( $x >= $width )
{
$x = 0;
$y++;
}
}
return $image;
}
clambert at whitecrown dot net
16-Jun-2001 01:47
WBMP images are Wireless Bitmaps, not Windows Bitmaps. WBMP is used for bandwidth constrained, black and white, limited devices such as PDAs and Cell Phones.