imagewbmp

    (PHP 4 >= 4.0.1, PHP 5, PHP 7, PHP 8)

    imagewbmp — Invia l'immagine al browser o in un file

    Descrizione

    imagewbmp(GdImage $image, resource|string|null $file = null, ?int $foreground_color = null): bool

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

    Elenco dei parametri

    image

    Una risorsa immagine, restituita da una delle funzioni di creazione immagine, come imagecreatetruecolor().

    file

    Il percorso in cui salvare il file. Se non è impostato o è null, viene restituito il flusso raw dell'immagine.

    foreground_color

    You can set the foreground color with this parameter by setting an identifier obtained from imagecolorallocate(). The default foreground color is black.

    Valori restituiti

    Restituisce true in caso di successo, false in caso di fallimento.

    Attenzione

    However, if libgd fails to output the image, this function returns true.

    Log delle modifiche

    Versione Descrizione
    8.0.0 image expects a GdImage instance now; previously, a valid gd resource was expected.
    8.0.0 foreground_color is nullable now.

    Esempi

    Example #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);
    ?>

    Example #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);
    ?>

    Example #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);
    ?>

    Vedere anche:

    • image2wbmp() - Invia l'immagine al browser o in un file
    • imagepng() - Output a PNG image to either the browser or a file
    • imagegif() - Invia l'immagine al browser o in un file
    • imagejpeg() - Invia l'immagine al browser o in un file
    • imagetypes() - Return the image types supported by this PHP build

    Found A Problem?

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    User Contributed Notes 2 notes

    up
    1
    andre at bynetworld dot com
    17 years ago
    In the previous note by -> lukeross at sys3175 dot co dot uk <- there is a coding error in the for() loops. After correcting the error, I found that this function did a great job of converting color images to 2 colors.
    The following is the corrected function code:

    function ImageColorFloydSteinberg($dst_img, $src_img) {
    ImageColorAllocate($dst_img, 0,0,0);
    ImageColorAllocate($dst_img, 255,255,255);
    $isx = ImageSX($src_img);
    $isy = ImageSY($src_img);
    $grey_img = ImageCreate($isx, $isy);
    for ($a = 0; $a <= 255; $a++) ImageColorAllocate($grey_img, $a,$a,$a);
    $isx -= 1; // To correct pixel count in source image width starting from 0
    $isy -= 1; // Correcting pixel count in source image height starting from 0
    for($x = 0; $x <= $isx; $x++) {
    for($y = 0; $y <= $isy; $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 <= $isx; $x++) {
    for($y = 0; $y <= $isy; $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 != $isx) {
    $color2 = ImageColorsForIndex($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 != $isy) {
    $color2 = ImageColorsForIndex($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 != $isx && $y != $isy) {
    $color2 = ImageColorsForIndex($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);
    }
    up
    0
    lukeross at sys3175 dot co dot uk
    22 years ago
    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));
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