imagewbmp

(PHP 4 >= 4.0.1, PHP 5)

imagewbmp — Gibt das Bild im Browser oder einer Datei aus.

Beschreibung

bool imagewbmp ( resource $image [, string $filename [, int $foreground ]] )

imagewbmp() outputs or save a WBMP version of the given image.

Parameter-Liste

image: Eine von den verschiedenen Erzeugungsfunktionen wie imagecreatetruecolor() gelieferte Grafikressource.
filename: Der Pfad unter dem das Bild gespeichert werden soll. Ist dies nicht gesetzt oder NULL wird der rohe Bilddatenstrom direkt ausgegeben.
foreground: You can set the foreground color with this parameter by setting an identifier obtained from imagecolorallocate(). The default foreground color is black.

Rückgabewerte

Gibt bei Erfolg TRUE zurück. Im Fehlerfall wird FALSE zurückgegeben.

Beispiele

Beispiel #1 Outputting a WBMP image


<?php
// Create a blank image and add some text
$im = imagecreatetruecolor(120, 20);
$text_color = imagecolorallocate($im, 233, 14, 91);
imagestring($im, 1, 5, 5,  'A Simple Text String', $text_color);

// Set the content type header - in this case image/vnd.wap.wbmp
// Hint: see image_type_to_mime_type() for content-types
header('Content-Type: image/vnd.wap.wbmp');

// Output the image
imagewbmp($im);

// Free up memory
imagedestroy($im);
?>

Beispiel #2 Saving the WBMP image


<?php
// Create a blank image and add some text
$im = imagecreatetruecolor(120, 20);
$text_color = imagecolorallocate($im, 233, 14, 91);
imagestring($im, 1, 5, 5,  'A Simple Text String', $text_color);

// Save the image
imagewbmp($im, 'simpletext.wbmp');

// Free up memory
imagedestroy($im);
?>

Beispiel #3 Outputting the image with a different foreground


<?php
// Create a blank image and add some text
$im = imagecreatetruecolor(120, 20);
$text_color = imagecolorallocate($im, 233, 14, 91);
imagestring($im, 1, 5, 5,  'A Simple Text String', $text_color);

// Set the content type header - in this case image/vnd.wap.wbmp
// Hint: see image_type_to_mime_type() for content-types
header('Content-Type: image/vnd.wap.wbmp');

// Set a replacement foreground color
$foreground_color = imagecolorallocate($im, 255, 0, 0);

imagewbmp($im, NULL, $foreground_color);

// Free up memory
imagedestroy($im);
?>

Anmerkungen

Hinweis:
WBMP support is only available if PHP was compiled against GD-1.8 or later.

Siehe auch

image2wbmp() - Gibt das Bild im Browser oder einer Datei aus.
imagepng() - Ausgabe eines Bildes im Browser oder als Datei im PNG-Format
imagegif() - Gibt das Bild im Browser oder einer Datei aus.
imagejpeg() - Gibt das Bild im Browser oder einer Datei aus.
imagetypes() - Gibt die von der aktuell verwendeten PHP-Version unterstützten Grafik-Formate zurück

add a note User Contributed Notes
imagewbmp

lukeross at sys3175 dot co dot uk
28-Feb-2002 10:57


As has been commented before, GD doesnt do a very good translation to 2-colours, especially for photos.  The following routine converts to two colours, I believe using error diffusion (the algorithm's nicked off news).  It's slow, but just about adequate for small images and low load.  I suspect it can be made much more efficient :-)



function ImageColorFloydSteinberg($dst_img, $src_img) {

    ImageColorAllocate($dst_img, 0,0,0);

    ImageColorAllocate($dst_img, 255,255,255);

    $grey_img = ImageCreate(ImageSX($src_img), ImageSY($src_img));

    for ($a = 0; $a <= 255; $a++) ImageColorAllocate($grey_img, $a,$a,$a);

    for($x = 0; $x <= ImageSX($src_img); $x++) {

        for($y = 0; $y <= ImageSY($src_img); $y++) {

            $color = ImageColorsForIndex($src_img, ImageColorAt($src_img, $x, $y));

            $greyscale = .299 * $color["red"] + .587 * $color["green"] + .114 * $color["blue"];

            ImageSetPixel($grey_img, $x, $y, ImageColorClosest($grey_img, $greyscale, $greyscale, $greyscale));

        }

    }

    for($x = 0; $x <= ImageSX($src_img); $x++) {

        for($y = 0; $y <= ImageSY($src_img); $y++) {

            $color = ImageColorsForIndex($grey_img, ImageColorAt($grey_img, $x, $y));

            if ($color["red"] > 128) {

                ImageSetPixel($dst_img, $x, $y, ImageColorClosest($dst_img,255,255,255));

                $err = $color["red"] - 255;

            } else {

                ImageSetPixel($dst_img, $x, $y, ImageColorClosest($dst_img,0,0,0));

                $err = $color["red"];

            }

            if ($x != ImageSx($src_img)) {

                $color2 = ImageColorsForIndex($grey_img, ImageColorAt($grey_img, $x+1, $y));

                $newgrey = $color2["red"] + $err * 7 / 16;

                ImageSetPixel($grey_img, $x+1, $y, ImageColorClosest($grey_img,$newgrey, $newgrey, $newgrey));

            }

            if ($x != 0) {

                $color2 = ImageColorsForIndex($grey_img, ImageColorAt($grey_img, $x-1, $y));

                $newgrey = $color2["red"] + $err * 3 / 16;

                ImageSetPixel($grey_img, $x-1, $y, ImageColorClosest($grey_img,$newgrey, $newgrey, $newgrey));

            }

            if ($y != ImageSy($src_img)) {

                $color2 = ImageColorsForIndex($grey_img, ImageColorAt($grey_img, $x, $y+1));

                $newgrey = $color2["red"] + $err * 5 / 16;

                ImageSetPixel($grey_img, $x, $y+1, ImageColorClosest($grey_img,$newgrey, $newgrey, $newgrey));

            }

            if ($x != ImageSx($src_img) && $y != ImageSy($src_img)) {

                $color2 = ImageColorsForIndex($grey_img, ImageColorAt($grey_img, $x+1, $y+1));

                $newgrey = $color2["red"] + $err / 16;

                ImageSetPixel($grey_img, $x+1, $y+1, ImageColorClosest($grey_img,$newgrey, $newgrey, $newgrey));

            }

            

        }

    }

    imagedestroy($grey_img);

}



To output your WBMP, use



ImageWBMP($final_img, "", ImageColorClosest(255,255,255));

marius
17-Jul-2001 02:10


You could also use:





@ImageWbmp ($im, "test.wbmp");





But I haven't test ist yet

flapper at redcube dot nl
23-May-2001 12:34


There is a hidden third parameter in the ImageWbmp function that serves as a threshold-holder. When using the function as in:





ImageWbmp ($im, "test.wbmp");





it generates a warning:





Warning: imagewbmp: invalid threshold value '-1'. It must be between 0 and 255 in blablabla





It does generate the image though but for a WML app. it cannot be used since the warning is laden with HTML-tags. To prevent the warning use the following example:





ImageWbmp ($im, "test.wbmp", 0);





The warning is no longer generated.

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imagexbm

imagetypes

Last updated: Fri, 18 May 2012