CODEWITHSUNDEEP
phpimagemagick
Cuongvn08
Cuongvn08

Reputation: 85

ImageMagick: cannot convert 24-bit bmp image to 8-bit bmp image

My programming platform is:

My code:

$img = new Imagick($image_input_24bit_bmp);
$img->setimagedepth(8);
$img->writeImage($image_output);

Then image_output is still 24-bit bmp image.

The thing I would like is convert the 24-bit bmp image to the 8-bit bmp image. Thanks.

Upvotes: 3

Views: 1767

Answers (2)

Mark Setchell
Mark Setchell

Reputation: 207345

You can force an 8-bit palettised BMP image (which is what I presume you mean) like this:

$im = new imagick('input.bmp');
$im->quantizeImage(256,Imagick::COLORSPACE_RGB,0,false,false);
$im->writeImage('result.bmp');

That will have a palette of 256 colours (each one 8-bit Red, plus 8-bit Green, plus 8-bit Blue), and each pixel will be represented by its index into that palette.

Upvotes: 1

NID
NID

Reputation: 3294

The setImageDepth just isn't enough. You need to quanitize the image.

Example:Test Script

$im = new imagick('stupid.png'); //an image of mine
$im->setImageFormat('PNG8');
$colors = min(255, $im->getImageColors());
$im->quantizeImage($colors, Imagick::COLORSPACE_RGB, 0, false, false );
$im->setImageDepth(8 /* bits */);
$im->writeImage('stupid8.png');

Upvotes: 1

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