Understanding Image Type in PHP with the ImageMagick Package

The function PHP 'getImageType' will return an integer, with that value being equal to the evaluated value of the IMGType Constants as defined by the ImageMagick class.  When accessing them, they look like "imagick::IMGTYPE_PALETTE", but with "_VALUE" values of: undefined, bilevel, grayscale, grayscalematte, palette, palettematte, truecolor, truecolormatte, colorseparation, colorseparationmatte, and optimize.  If you were to print out these values, you would have '0' for undefined, '1' for bilevel, '2' for grayscale, and so on.

For a BMP picture drawn in paint, I got back the value # 4 - Palette.  For a BMP or JPEG photograph of the ocean or jungle, I got back the value # 6 - Truecolor.  For an animated GIF file, I got back the value # 5 - Palette Matte.  For a black-and-white JPEG drawing, I got back the value # 2 - Grayscale.  These are the most common results I have gotten back with this function.

Some sample code :

<?php

            // Author: holdoffhunger@gmail.com
   
        // Imagick Type
        // ---------------------------------------------

    $imagick_type = new Imagick();
   
        // Open File
        // ---------------------------------------------
       
    $file_to_grab = "image_workshop_directory/test.bmp";
   
    $file_handle_for_viewing_image_file = fopen($file_to_grab, 'a+');
   
        // Grab File
        // ---------------------------------------------

    $imagick_type->readImageFile($file_handle_for_viewing_image_file);
   
        // Get Image Type Value
        // ---------------------------------------------
       
    $image_type = $imagick_type->getImageType();
   
        // Interpret Image Type Value
        // ---------------------------------------------

    switch($image_type)
    {
        case imagick::IMGTYPE_UNDEFINED:
            $image_type_title = "Undefined";
            break;
           
        case imagick::IMGTYPE_BILEVEL:
            $image_type_title = "Bilevel";
            break;
           
        case imagick::IMGTYPE_GRAYSCALE:
            $image_type_title = "Grayscale";
            break;
           
        case imagick::IMGTYPE_GRAYSCALEMATTE:
            $image_type_title = "Grayscale Matte";
            break;
           
        case imagick::IMGTYPE_PALETTE:
            $image_type_title = "Palette";
            break;
           
        case imagick::IMGTYPE_PALETTEMATTE:
            $image_type_title = "Palette Matte";
            break;
           
        case imagick::IMGTYPE_TRUECOLOR:
            $image_type_title = "Truecolor";
            break;
           
        case imagick::IMGTYPE_TRUECOLORMATTE:
            $image_type_title = "Truecolor Matte";
            break;
           
        case imagick::IMGTYPE_COLORSEPARATION:
            $image_type_title = "Color Separation";
            break;
           
        case imagick::IMGTYPE_COLORSEPARATIONMATTE:
            $image_type_title = "Color Separation Matte";
            break;
           
        case imagick::IMGTYPE_OPTIMIZE:
            $image_type_title = "Optimize";
            break;
    }
   
        // Print Image Type Value
        // ---------------------------------------------
       
    print("# $image_type - $image_type_title");

?>

Official Function Page: http://www.php.net/manual/en/imagick.getimagetype.php

// Note: All code appearing on the PHP Revolution blog by the blog owner is released under the Hacktivismo Enhanced-Source Software License Agreement (HESSLA), unless otherwise noted.  http://www.hacktivismo.com/about/hessla.php