imagecopymergegray

(PHP 4 >= 4.0.6, PHP 5)

imagecopymergegrayCopy and merge part of an image with gray scale

Description

bool imagecopymergegray ( resource $dst_im , resource $src_im , int $dst_x , int $dst_y , int $src_x , int $src_y , int $src_w , int $src_h , int $pct )

imagecopymergegray() copy a part of src_im onto dst_im starting at the x,y coordinates src_x, src_y with a width of src_w and a height of src_h. The portion defined will be copied onto the x,y coordinates, dst_x and dst_y.

This function is identical to imagecopymerge() except that when merging it preserves the hue of the source by converting the destination pixels to gray scale before the copy operation.

Parameters

dst_im

Destination image link resource.

src_im

Source image link resource.

dst_x

x-coordinate of destination point.

dst_y

y-coordinate of destination point.

src_x

x-coordinate of source point.

src_y

y-coordinate of source point.

src_w

Source width.

src_h

Source height.

pct

The src_im will be changed to grayscale according to pct where 0 is fully grayscale and 100 is unchanged. When pct = 100 this function behaves identically to imagecopy() for pallete images, except for ignoring alpha components, while it implements alpha transparency for true colour images.

Return Values

Returns TRUE on success or FALSE on failure.

Examples

Example #1 imagecopymergegray() usage

<?php
// Create image instances
$dest imagecreatefromgif('php.gif');
$src imagecreatefromgif('php.gif');

// Copy and merge - Gray = 20%
imagecopymergegray($dest$src1010001004720);

// Output and free from memory
header('Content-Type: image/gif');
imagegif($dest);

imagedestroy($dest);
imagedestroy($src);
?>

Коментарии

This function don't work properly for me on trucolerimages (have not tried yet for other types) it jsut produce a part-grayscale image, and some color get mesed up.
I found a workaround here:
http://www.phpbuilder.com/columns/cash20030526.php3?page=2

[quote]
Advanced Image Editing Under the GD Library
Colorizing
Colorizing images is fairly easy to do. The easiest way to colorize an image is fairly simple to grasp. Create an image of the same dimensions and fill that image with the color you want to change it to. This new image is then placed on top of the older image, giving it a colorized look.

<?php 
function imagecolorize(&$im,&$col,$pct) { 
   
// Get the image's width 
   
$im_w imagesx($im); 
   
// Get the image's height 
   
$im_h imagesy($im); 
   
// Set a pixel with the color, so we can get it easily 
   
$setpixel imagesetpixel($im,$im_w,0,$col); 
   
// Get the color 
   
$index imagecolorat($im,$im_w,0); 
   
// Find the color in the index 
   
$rgb imagecolorsforindex($im,$index); 
   
// Get the red value 
   
$r $rgb["red"]; 
   
// Get the green value 
   
$g $rgb["green"]; 
   
// Get the blue value 
   
$b $rgb["blue"]; 
   
// Create the layover 
   
$layover imagecreate($im_w,$im_h); 
   
// Allocate the color on this image 
   
$color imagecolorallocate($layover,$r,$g,$b); 
   
// Fill the image with the new color (this really isn't needed) 
   
$fill imagefill($layover,0,0,$color); 
   
// Merge the layover on top of the older image 
   
$merge imagecopymerge($im,$layover,0,0,0,0,$im_w,$im_h,$pct); 
   
imagedestroy($layover); // Destroy the layover 

?> 

If we use a blue layover RGB(0,0,255), we get this result:
[/quote]

if you use black or gray, its not perfekt, but better than nothing ;)
2003-10-09 03:45:22
http://php5.kiev.ua/manual/ru/function.imagecopymergegray.html
# very fast way to generate a grayscal-
# image from a true color image

#...

# --- quick grayscale image
for ($y = 0; $y <$img_height; $y++) { 
 for ($x = 0; $x <$img_width; $x++) { 

 # here we extract the green from 
 # the pixel at x,y , to use it as gray value
 $gray = (ImageColorAt($image, $x, $y) >> 8) & 0xFF;

 # a more exact way would be this:
 # $rgb = ImageColorAt($image, $x, $y);
 # $red = ($rgb >> 16) & 0xFF;
 # $green = (trgb >> 8) & 0xFF;
 # $blue = $rgb & 0xFF;
 # $gray = (int)(($red+$green+$blue)/4); 

 # and here we set the new pixel/color
  imagesetpixel ($image, $x, $y, 
  ImageColorAllocate ($image, $gray,$gray,$gray));
 }
}
 
# ...
2003-10-18 03:08:23
http://php5.kiev.ua/manual/ru/function.imagecopymergegray.html
in addition to code_couturier - try this formula to calculate gray-value (luminance) in his "more exact" way:

$gray = round(.299*$red + .587*$green + .114*$blue);
2004-02-15 18:25:45
http://php5.kiev.ua/manual/ru/function.imagecopymergegray.html
In addition to code_couturier too: his code will produce blue pictures, because the value he uses to set the pixel color (the code is incomplete: I first thought it should be $gray) is between 0 and 255, which corresponds to blue levels.

To convert the picture to grayscale, use the following code:

<?php
   
// replace with your files
   
$originalFileName    "colorPicture.jpg";
   
$destinationFileName "bwPicture.jpg";
   
   
// create a copy of the original image
    // works with jpg images
    // fell free to adapt to other formats ;)
   
$fullPath explode(".",$originalFileName);
   
$lastIndex sizeof($fullPath) - 1;
   
$extension $fullPath[$lastIndex];
    if (
preg_match("/jpg|jpeg|JPG|JPEG/"$extension)){
       
$sourceImage imagecreatefromjpeg($originalFileName);
    }

   
// get image dimensions
   
$img_width  imageSX($sourceImage);
   
$img_height imageSY($sourceImage);

   
// convert to grayscale
    // note: this will NOT affect your original image, unless
    // originalFileName and destinationFileName are the same
   
for ($y 0$y <$img_height$y++) { 
        for (
$x 0$x <$img_width$x++) { 
           
$rgb imagecolorat($sourceImage$x$y);
           
$red   = ($rgb >> 16) & 0xFF;
           
$green = ($rgb >> 8)  & 0xFF;
           
$blue  $rgb 0xFF;

           
$gray round(.299*$red .587*$green .114*$blue);
           
           
// shift gray level to the left
           
$grayR $gray << 16;   // R: red
           
$grayG $gray << 8;    // G: green
           
$grayB $gray;         // B: blue
           
            // OR operation to compute gray value
           
$grayColor $grayR $grayG $grayB;

           
// set the pixel color
           
imagesetpixel ($sourceImage$x$y$grayColor);
           
imagecolorallocate ($sourceImage$gray$gray$gray);
        }
    }

   
// copy pixel values to new file buffer
   
$destinationImage ImageCreateTrueColor($img_width$img_height);
   
imagecopy($destinationImage$sourceImage0000$img_width$img_height);

   
// create file on disk
   
imagejpeg($destinationImage$destinationFileName);
   
   
// destroy temp image buffers
   
imagedestroy($destinationImage);   
   
imagedestroy($sourceImage);
?>

Copy-paste, replace the file names on the top and there you go (picture files must be in same folder as this script. If not, you will have to do your own file management).
2004-04-15 10:18:56
http://php5.kiev.ua/manual/ru/function.imagecopymergegray.html
Автор:
//  Using the same code I found here on php.net, 
// I was able to figure out how to convert GIF (or any other
// format GD supports) to CIP format.  CIP is the image
// format for Cisco IP Phones...  7905/7940 and 7960 
// models...  Hope someone finds this useful and make it 
// better... 

/////// GIF2CIP PHP code ///////

// Convert image in memory to grayscale
    $img_width  = imageSX($im2);
    $img_height = imageSY($im2);

   // convert to grayscale
   // note: this will NOT affect your original image, unless
   // originalFileName and destinationFileName are the same
   for ($y = 0; $y <$img_height; $y++) { 
       for ($x = 0; $x <$img_width; $x++) { 
           $rgb = imagecolorat($im2, $x, $y);
           $red  = ($rgb >> 16) & 0xFF;
           $green = ($rgb >> 8)  & 0xFF;
           $blue  = $rgb & 0xFF;

           $gray = round(.299*$red + .587*$green + .114*$blue);
           
           // shift gray level to the left
           $grayR = $gray << 16;  // R: red
           $grayG = $gray << 8;    // G: green
           $grayB = $gray;        // B: blue
           
           // OR operation to compute gray value
           $grayColor = $grayR | $grayG | $grayB;

           // set the pixel color
           imagesetpixel ($im2, $x, $y, $grayColor);
           imagecolorallocate ($im2, $gray, $gray, $gray);
       }
   }
/////////////////////////////////////////////////////////

    // Modifies palette to only 4-colors (CIP Images on 7905/7940 & 7960 is 2-bit color)
    ImageTrueColorToPalette2($im2,FALSE,4);

    // Basic header for CIP Image files...
    header ("Content-type: text/xml");
    echo "<CiscoIPPhoneImage> ";
    echo "<LocationX>-1</LocationX> ";
    echo "<LocationY>-1</LocationY> ";
    echo "<Width>132</Width> ";
    echo "<Height>65</Height> ";
    echo "<Depth>2</Depth> ";
    echo "<Data>";

// get image dimensions (almost same code as above)
   $img_width  = imageSX($im2);
   $img_height = imageSY($im2);

   // convert to grayscale
   // note: this will NOT affect your original image, unless
   // originalFileName and destinationFileName are the same
   for ($y = 0; $y <$img_height; $y++) { 
       for ($x = 0; $x+4 <$img_width; $x = $x+4) 
       { 
            for ($ix = 0; $ix < 4; $ix++)
            {
               $rgb = imagecolorat($im2, $x + $ix, $y);

               // I came up with this translation on my own
               // Some smart person is bound to perfect it
               if ($rgb=="2") {$rgb=0;$Gray1[$ix] = $rgb;continue;}
               if ($rgb=="0") {$rgb=2;$Gray1[$ix] = $rgb;continue;}
               if ($rgb=="1") {$rgb=1;$Gray1[$ix] = $rgb;continue;}
               if ($rgb=="3") {$rgb=3;$Gray1[$ix] = $rgb;continue;}
           }
                $gray1 = $Gray1[0];
                $gray2 = $Gray1[1] << 2;
                $gray3 = $Gray1[2] << 4;
                $gray4 = $Gray1[3] << 6;
               
                // Pack 4 pixels into a single byte for CIP images
                $grey = $gray1 | $gray2 | $gray3 | $gray4;

                // CIP image data is sent in HEX, strtoupper is not really needed.
                $code = strtoupper(dechex($grey)); 

                // My quick fix to padding single HEX values
                if (strlen($code)==1) $code = "0".$code;
                echo $code;
               
       }

   }
    echo "</Data>";
    echo "<Title>$myvar</Title> ";
    echo "<Prompt>$city</Prompt> ";
    echo "</CiscoIPPhoneImage>";
    exit;
2005-08-15 15:31:48
http://php5.kiev.ua/manual/ru/function.imagecopymergegray.html
I've changed a little switch251's code and here we have sephia effect
<?php
   
// replace with your files
   
$originalFileName    $filename;
   
$destinationFileName "2".$filename;
   
   
// create a copy of the original image
    // works with jpg images
    // fell free to adapt to other formats ;)
   
$fullPath explode(".",$originalFileName);
   
$lastIndex sizeof($fullPath) - 1;
   
$extension $fullPath[$lastIndex];
    if (
preg_match("/jpg|jpeg|JPG|JPEG/"$extension))
    {
       
$sourceImage imagecreatefromjpeg($originalFileName);
    }

   
// get image dimensions
   
$img_width  imageSX($sourceImage);
   
$img_height imageSY($sourceImage);

   
// convert to grayscale
    // note: this will NOT affect your original image, unless
    // originalFileName and destinationFileName are the same
   
for ($y 0$y <$img_height$y++) 
    { 
        for (
$x 0$x <$img_width$x++) 
        { 
           
$rgb imagecolorat($sourceImage$x$y);
           
$red   = ($rgb >> 16) & 0xFF;
           
$green = ($rgb >> 8)  & 0xFF;
           
$blue  $rgb 0xFF;

         
//sephia
           
$red2 min($red*.393 $green*.769 $blue*.189,255);
           
$green2 min($red*.349 $green*.686 $blue*.168,255);
           
$blue2  min($red*.272 $green*.534 $blue*.131,255);
           
// shift gray level to the left
           
           
$grayR $red2 << 16;   // R: red
           
$grayG $green2 << ;    // G: green
           
$grayB $blue2;         // B: blue
           
            // OR operation to compute gray value
           
$grayColor $grayR $grayG $grayB;

           
           
// set the pixel color
           
imagesetpixel ($sourceImage$x$y$grayColor);
           
imagecolorallocate ($sourceImage$gray$gray$gray);
        }
    }

   
// copy pixel values to new file buffer
   
$destinationImage ImageCreateTrueColor($img_width$img_height);
   
imagecopy($destinationImage$sourceImage0000$img_width$img_height);

   
// create file on disk
   
imagejpeg($destinationImage$destinationFileName);
   
   
// destroy temp image buffers
   
imagedestroy($destinationImage);   
   
imagedestroy($sourceImage);
?>
2007-04-15 17:17:59
http://php5.kiev.ua/manual/ru/function.imagecopymergegray.html
gray effect :)
<?php
header
('content-type:image/png');
$url_img 'my_image.png';
$img imagecreatefrompng($url_img);
$x imagesx($img);
$y imagesy($img);
$gray_img imagecreatetruecolor($x$y);
imagecolorallocate($gray_img000);
for (
$i 0$i $x$i++) {
  for (
$j 0$j $y$j++) {
   
$rgb imagecolorat($img$i$j);
   
$r = ($rgb >> 16) & 0xFF;
   
$g = ($rgb >> 8) & 0xFF;
   
$b $rgb 0xFF;
     
//for gray mode $r = $g = $b
   
$color max(array($r$g$b));
   
$gray_color imagecolorexact($new_img$color$color,   $color);
     
imagesetpixel($gray_img$i$j$gray_color);
   }
}
?>
2008-05-09 20:59:41
http://php5.kiev.ua/manual/ru/function.imagecopymergegray.html
grayscale conversion is built-in with imagefilter(). 

<?php
     
/* other code */

     
$image imagecreatefromjpeg('some.jpg');
     
imagefilter($imageIMG_FILTER_GRAYSCALE);

     
/* other code (ie save) */

     
imagedestroy($image);

     
/* other code */
?>

you could create the sepia effect by the following:

<?php
     
/* other code */

     
$image imagecreatefromjpeg('some.jpg');
     
imagefilter($imageIMG_FILTER_GRAYSCALE);
     
imagefilter($imageIMG_FILTER_COLORIZE1126620);
     
//Wikipedia RGB definition of sepia

     /* other code (ie save) */

     
imagedestroy($image);

     
/* other code */
?>
2009-10-16 18:54:04
http://php5.kiev.ua/manual/ru/function.imagecopymergegray.html

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