Skip to content

Commit

Permalink
Adding new perceptual hash implementation from @smithtek, code by @b1…
Browse files Browse the repository at this point in the history 
…rdex

See issue jenssegers#52

Squashed commit of the following:

commit 39baec8
Author: Anatoly Pashin <[email protected]>
Date:   Thu Jul 9 12:45:26 2020 +1000

    Fix cs

commit aa31683
Author: Anatoly Pashin <[email protected]>
Date:   Thu Jul 9 12:45:17 2020 +1000

    Fix cs

commit df4555d
Author: Anatoly Pashin <[email protected]>
Date:   Thu Jul 9 12:40:40 2020 +1000

    Fix typo

commit b422ea4
Author: Anatoly Pashin <[email protected]>
Date:   Thu Jul 9 12:39:20 2020 +1000

    Add PerceptualHash2
  • Loading branch information
Vincent Chalnot committed Nov 22, 2020
1 parent 5fd4dbd commit 3ee829e
Show file tree
Hide file tree
Showing 2 changed files with 211 additions and 0 deletions.
207 changes: 207 additions & 0 deletions src/Implementations/PerceptualHash2.php
View file
Original file line number Diff line number Diff line change
@@ -0,0 +1,207 @@
<?php
declare(strict_types=1);

namespace Jenssegers\ImageHash\Implementations;

use Intervention\Image\Image;
use Jenssegers\ImageHash\Hash;
use Jenssegers\ImageHash\Implementation;
use LogicException;

/**
* This is an optimized version of the original {@see PerceptualHash}
* based on some R&D. You can read more at the issue page.
*
* @see https://github.com/jenssegers/imagehash/issues/52
*/
final class PerceptualHash2 implements Implementation
{
const DCT_11_16 = [
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
[0.99518473, 0.95694034, 0.88192126, 0.77301045, 0.63439328, 0.47139674, 0.29028468, 0.09801714, -0.09801714, -0.29028468, -0.47139674, -0.63439328, -0.77301045, -0.88192126, -0.95694034, -0.99518473],
[0.98078528, 0.83146961, 0.55557023, 0.19509032, -0.19509032, -0.55557023, -0.83146961, -0.98078528, -0.98078528, -0.83146961, -0.55557023, -0.19509032, 0.19509032, 0.55557023, 0.83146961, 0.98078528],
[0.95694034, 0.63439328, 0.09801714, -0.47139674, -0.88192126, -0.99518473, -0.77301045, -0.29028468, 0.29028468, 0.77301045, 0.99518473, 0.88192126, 0.47139674, -0.09801714, -0.63439328, -0.95694034],
[0.92387953, 0.38268343, -0.38268343, -0.92387953, -0.92387953, -0.38268343, 0.38268343, 0.92387953, 0.92387953, 0.38268343, -0.38268343, -0.92387953, -0.92387953, -0.38268343, 0.38268343, 0.92387953],
[0.88192126, 0.09801714, -0.77301045, -0.95694034, -0.29028468, 0.63439328, 0.99518473, 0.47139674, -0.47139674, -0.99518473, -0.63439328, 0.29028468, 0.95694034, 0.77301045, -0.09801714, -0.88192126],
[0.83146961, -0.19509032, -0.98078528, -0.55557023, 0.55557023, 0.98078528, 0.19509032, -0.83146961, -0.83146961, 0.19509032, 0.98078528, 0.55557023, -0.55557023, -0.98078528, -0.19509032, 0.83146961],
[0.77301045, -0.47139674, -0.95694034, 0.09801714, 0.99518473, 0.29028468, -0.88192126, -0.63439328, 0.63439328, 0.88192126, -0.29028468, -0.99518473, -0.09801714, 0.95694034, 0.47139674, -0.77301045],
[0.70710678, -0.70710678, -0.70710678, 0.70710678, 0.70710678, -0.70710678, -0.70710678, 0.70710678, 0.70710678, -0.70710678, -0.70710678, 0.70710678, 0.70710678, -0.70710678, -0.70710678, 0.70710678],
[0.63439328, -0.88192126, -0.29028468, 0.99518473, -0.09801714, -0.95694034, 0.47139674, 0.77301045, -0.77301045, -0.47139674, 0.95694034, 0.09801714, -0.99518473, 0.29028468, 0.88192126, -0.63439328],
[0.55557023, -0.98078528, 0.19509032, 0.83146961, -0.83146961, -0.19509032, 0.98078528, -0.55557023, -0.55557023, 0.98078528, -0.19509032, -0.83146961, 0.83146961, 0.19509032, -0.98078528, 0.55557023],
];
const DCT_11_32 = [
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
[0.99879546, 0.98917651, 0.97003125, 0.94154407, 0.90398929, 0.85772861, 0.80320753, 0.74095113, 0.67155895, 0.5956993, 0.51410274, 0.42755509, 0.33688985, 0.24298018, 0.14673047, 0.04906767, -0.04906767, -0.14673047, -0.24298018, -0.33688985, -0.42755509, -0.51410274, -0.5956993, -0.67155895, -0.74095113, -0.80320753, -0.85772861, -0.90398929, -0.94154407, -0.97003125, -0.98917651, -0.99879546],
[0.99518473, 0.95694034, 0.88192126, 0.77301045, 0.63439328, 0.47139674, 0.29028468, 0.09801714, -0.09801714, -0.29028468, -0.47139674, -0.63439328, -0.77301045, -0.88192126, -0.95694034, -0.99518473, -0.99518473, -0.95694034, -0.88192126, -0.77301045, -0.63439328, -0.47139674, -0.29028468, -0.09801714, 0.09801714, 0.29028468, 0.47139674, 0.63439328, 0.77301045, 0.88192126, 0.95694034, 0.99518473],
[0.98917651, 0.90398929, 0.74095113, 0.51410274, 0.24298018, -0.04906767, -0.33688985, -0.5956993, -0.80320753, -0.94154407, -0.99879546, -0.97003125, -0.85772861, -0.67155895, -0.42755509, -0.14673047, 0.14673047, 0.42755509, 0.67155895, 0.85772861, 0.97003125, 0.99879546, 0.94154407, 0.80320753, 0.5956993, 0.33688985, 0.04906767, -0.24298018, -0.51410274, -0.74095113, -0.90398929, -0.98917651],
[0.98078528, 0.83146961, 0.55557023, 0.19509032, -0.19509032, -0.55557023, -0.83146961, -0.98078528, -0.98078528, -0.83146961, -0.55557023, -0.19509032, 0.19509032, 0.55557023, 0.83146961, 0.98078528, 0.98078528, 0.83146961, 0.55557023, 0.19509032, -0.19509032, -0.55557023, -0.83146961, -0.98078528, -0.98078528, -0.83146961, -0.55557023, -0.19509032, 0.19509032, 0.55557023, 0.83146961, 0.98078528],
[0.97003125, 0.74095113, 0.33688985, -0.14673047, -0.5956993, -0.90398929, -0.99879546, -0.85772861, -0.51410274, -0.04906767, 0.42755509, 0.80320753, 0.98917651, 0.94154407, 0.67155895, 0.24298018, -0.24298018, -0.67155895, -0.94154407, -0.98917651, -0.80320753, -0.42755509, 0.04906767, 0.51410274, 0.85772861, 0.99879546, 0.90398929, 0.5956993, 0.14673047, -0.33688985, -0.74095113, -0.97003125],
[0.95694034, 0.63439328, 0.09801714, -0.47139674, -0.88192126, -0.99518473, -0.77301045, -0.29028468, 0.29028468, 0.77301045, 0.99518473, 0.88192126, 0.47139674, -0.09801714, -0.63439328, -0.95694034, -0.95694034, -0.63439328, -0.09801714, 0.47139674, 0.88192126, 0.99518473, 0.77301045, 0.29028468, -0.29028468, -0.77301045, -0.99518473, -0.88192126, -0.47139674, 0.09801714, 0.63439328, 0.95694034],
[0.94154407, 0.51410274, -0.14673047, -0.74095113, -0.99879546, -0.80320753, -0.24298018, 0.42755509, 0.90398929, 0.97003125, 0.5956993, -0.04906767, -0.67155895, -0.98917651, -0.85772861, -0.33688985, 0.33688985, 0.85772861, 0.98917651, 0.67155895, 0.04906767, -0.5956993, -0.97003125, -0.90398929, -0.42755509, 0.24298018, 0.80320753, 0.99879546, 0.74095113, 0.14673047, -0.51410274, -0.94154407],
[0.92387953, 0.38268343, -0.38268343, -0.92387953, -0.92387953, -0.38268343, 0.38268343, 0.92387953, 0.92387953, 0.38268343, -0.38268343, -0.92387953, -0.92387953, -0.38268343, 0.38268343, 0.92387953, 0.92387953, 0.38268343, -0.38268343, -0.92387953, -0.92387953, -0.38268343, 0.38268343, 0.92387953, 0.92387953, 0.38268343, -0.38268343, -0.92387953, -0.92387953, -0.38268343, 0.38268343, 0.92387953],
[0.90398929, 0.24298018, -0.5956993, -0.99879546, -0.67155895, 0.14673047, 0.85772861, 0.94154407, 0.33688985, -0.51410274, -0.98917651, -0.74095113, 0.04906767, 0.80320753, 0.97003125, 0.42755509, -0.42755509, -0.97003125, -0.80320753, -0.04906767, 0.74095113, 0.98917651, 0.51410274, -0.33688985, -0.94154407, -0.85772861, -0.14673047, 0.67155895, 0.99879546, 0.5956993, -0.24298018, -0.90398929],
[0.88192126, 0.09801714, -0.77301045, -0.95694034, -0.29028468, 0.63439328, 0.99518473, 0.47139674, -0.47139674, -0.99518473, -0.63439328, 0.29028468, 0.95694034, 0.77301045, -0.09801714, -0.88192126, -0.88192126, -0.09801714, 0.77301045, 0.95694034, 0.29028468, -0.63439328, -0.99518473, -0.47139674, 0.47139674, 0.99518473, 0.63439328, -0.29028468, -0.95694034, -0.77301045, 0.09801714, 0.88192126],
];
const DCT_11_64 = [
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
[0.99969882, 0.99729046, 0.99247953, 0.98527764, 0.97570213, 0.96377607, 0.94952818, 0.9329928, 0.91420976, 0.8932243, 0.87008699, 0.84485357, 0.81758481, 0.78834643, 0.75720885, 0.72424708, 0.68954054, 0.65317284, 0.61523159, 0.57580819, 0.53499762, 0.49289819, 0.44961133, 0.40524131, 0.35989504, 0.31368174, 0.26671276, 0.21910124, 0.17096189, 0.12241068, 0.07356456, 0.02454123, -0.02454123, -0.07356456, -0.12241068, -0.17096189, -0.21910124, -0.26671276, -0.31368174, -0.35989504, -0.40524131, -0.44961133, -0.49289819, -0.53499762, -0.57580819, -0.61523159, -0.65317284, -0.68954054, -0.72424708, -0.75720885, -0.78834643, -0.81758481, -0.84485357, -0.87008699, -0.8932243, -0.91420976, -0.9329928, -0.94952818, -0.96377607, -0.97570213, -0.98527764, -0.99247953, -0.99729046, -0.99969882],
[0.99879546, 0.98917651, 0.97003125, 0.94154407, 0.90398929, 0.85772861, 0.80320753, 0.74095113, 0.67155895, 0.5956993, 0.51410274, 0.42755509, 0.33688985, 0.24298018, 0.14673047, 0.04906767, -0.04906767, -0.14673047, -0.24298018, -0.33688985, -0.42755509, -0.51410274, -0.5956993, -0.67155895, -0.74095113, -0.80320753, -0.85772861, -0.90398929, -0.94154407, -0.97003125, -0.98917651, -0.99879546, -0.99879546, -0.98917651, -0.97003125, -0.94154407, -0.90398929, -0.85772861, -0.80320753, -0.74095113, -0.67155895, -0.5956993, -0.51410274, -0.42755509, -0.33688985, -0.24298018, -0.14673047, -0.04906767, 0.04906767, 0.14673047, 0.24298018, 0.33688985, 0.42755509, 0.51410274, 0.5956993, 0.67155895, 0.74095113, 0.80320753, 0.85772861, 0.90398929, 0.94154407, 0.97003125, 0.98917651, 0.99879546],
[0.99729046, 0.97570213, 0.9329928, 0.87008699, 0.78834643, 0.68954054, 0.57580819, 0.44961133, 0.31368174, 0.17096189, 0.02454123, -0.12241068, -0.26671276, -0.40524131, -0.53499762, -0.65317284, -0.75720885, -0.84485357, -0.91420976, -0.96377607, -0.99247953, -0.99969882, -0.98527764, -0.94952818, -0.8932243, -0.81758481, -0.72424708, -0.61523159, -0.49289819, -0.35989504, -0.21910124, -0.07356456, 0.07356456, 0.21910124, 0.35989504, 0.49289819, 0.61523159, 0.72424708, 0.81758481, 0.8932243, 0.94952818, 0.98527764, 0.99969882, 0.99247953, 0.96377607, 0.91420976, 0.84485357, 0.75720885, 0.65317284, 0.53499762, 0.40524131, 0.26671276, 0.12241068, -0.02454123, -0.17096189, -0.31368174, -0.44961133, -0.57580819, -0.68954054, -0.78834643, -0.87008699, -0.9329928, -0.97570213, -0.99729046],
[0.99518473, 0.95694034, 0.88192126, 0.77301045, 0.63439328, 0.47139674, 0.29028468, 0.09801714, -0.09801714, -0.29028468, -0.47139674, -0.63439328, -0.77301045, -0.88192126, -0.95694034, -0.99518473, -0.99518473, -0.95694034, -0.88192126, -0.77301045, -0.63439328, -0.47139674, -0.29028468, -0.09801714, 0.09801714, 0.29028468, 0.47139674, 0.63439328, 0.77301045, 0.88192126, 0.95694034, 0.99518473, 0.99518473, 0.95694034, 0.88192126, 0.77301045, 0.63439328, 0.47139674, 0.29028468, 0.09801714, -0.09801714, -0.29028468, -0.47139674, -0.63439328, -0.77301045, -0.88192126, -0.95694034, -0.99518473, -0.99518473, -0.95694034, -0.88192126, -0.77301045, -0.63439328, -0.47139674, -0.29028468, -0.09801714, 0.09801714, 0.29028468, 0.47139674, 0.63439328, 0.77301045, 0.88192126, 0.95694034, 0.99518473],
[0.99247953, 0.9329928, 0.81758481, 0.65317284, 0.44961133, 0.21910124, -0.02454123, -0.26671276, -0.49289819, -0.68954054, -0.84485357, -0.94952818, -0.99729046, -0.98527764, -0.91420976, -0.78834643, -0.61523159, -0.40524131, -0.17096189, 0.07356456, 0.31368174, 0.53499762, 0.72424708, 0.87008699, 0.96377607, 0.99969882, 0.97570213, 0.8932243, 0.75720885, 0.57580819, 0.35989504, 0.12241068, -0.12241068, -0.35989504, -0.57580819, -0.75720885, -0.8932243, -0.97570213, -0.99969882, -0.96377607, -0.87008699, -0.72424708, -0.53499762, -0.31368174, -0.07356456, 0.17096189, 0.40524131, 0.61523159, 0.78834643, 0.91420976, 0.98527764, 0.99729046, 0.94952818, 0.84485357, 0.68954054, 0.49289819, 0.26671276, 0.02454123, -0.21910124, -0.44961133, -0.65317284, -0.81758481, -0.9329928, -0.99247953],
[0.98917651, 0.90398929, 0.74095113, 0.51410274, 0.24298018, -0.04906767, -0.33688985, -0.5956993, -0.80320753, -0.94154407, -0.99879546, -0.97003125, -0.85772861, -0.67155895, -0.42755509, -0.14673047, 0.14673047, 0.42755509, 0.67155895, 0.85772861, 0.97003125, 0.99879546, 0.94154407, 0.80320753, 0.5956993, 0.33688985, 0.04906767, -0.24298018, -0.51410274, -0.74095113, -0.90398929, -0.98917651, -0.98917651, -0.90398929, -0.74095113, -0.51410274, -0.24298018, 0.04906767, 0.33688985, 0.5956993, 0.80320753, 0.94154407, 0.99879546, 0.97003125, 0.85772861, 0.67155895, 0.42755509, 0.14673047, -0.14673047, -0.42755509, -0.67155895, -0.85772861, -0.97003125, -0.99879546, -0.94154407, -0.80320753, -0.5956993, -0.33688985, -0.04906767, 0.24298018, 0.51410274, 0.74095113, 0.90398929, 0.98917651],
[0.98527764, 0.87008699, 0.65317284, 0.35989504, 0.02454123, -0.31368174, -0.61523159, -0.84485357, -0.97570213, -0.99247953, -0.8932243, -0.68954054, -0.40524131, -0.07356456, 0.26671276, 0.57580819, 0.81758481, 0.96377607, 0.99729046, 0.91420976, 0.72424708, 0.44961133, 0.12241068, -0.21910124, -0.53499762, -0.78834643, -0.94952818, -0.99969882, -0.9329928, -0.75720885, -0.49289819, -0.17096189, 0.17096189, 0.49289819, 0.75720885, 0.9329928, 0.99969882, 0.94952818, 0.78834643, 0.53499762, 0.21910124, -0.12241068, -0.44961133, -0.72424708, -0.91420976, -0.99729046, -0.96377607, -0.81758481, -0.57580819, -0.26671276, 0.07356456, 0.40524131, 0.68954054, 0.8932243, 0.99247953, 0.97570213, 0.84485357, 0.61523159, 0.31368174, -0.02454123, -0.35989504, -0.65317284, -0.87008699, -0.98527764],
[0.98078528, 0.83146961, 0.55557023, 0.19509032, -0.19509032, -0.55557023, -0.83146961, -0.98078528, -0.98078528, -0.83146961, -0.55557023, -0.19509032, 0.19509032, 0.55557023, 0.83146961, 0.98078528, 0.98078528, 0.83146961, 0.55557023, 0.19509032, -0.19509032, -0.55557023, -0.83146961, -0.98078528, -0.98078528, -0.83146961, -0.55557023, -0.19509032, 0.19509032, 0.55557023, 0.83146961, 0.98078528, 0.98078528, 0.83146961, 0.55557023, 0.19509032, -0.19509032, -0.55557023, -0.83146961, -0.98078528, -0.98078528, -0.83146961, -0.55557023, -0.19509032, 0.19509032, 0.55557023, 0.83146961, 0.98078528, 0.98078528, 0.83146961, 0.55557023, 0.19509032, -0.19509032, -0.55557023, -0.83146961, -0.98078528, -0.98078528, -0.83146961, -0.55557023, -0.19509032, 0.19509032, 0.55557023, 0.83146961, 0.98078528],
[0.97570213, 0.78834643, 0.44961133, 0.02454123, -0.40524131, -0.75720885, -0.96377607, -0.98527764, -0.81758481, -0.49289819, -0.07356456, 0.35989504, 0.72424708, 0.94952818, 0.99247953, 0.84485357, 0.53499762, 0.12241068, -0.31368174, -0.68954054, -0.9329928, -0.99729046, -0.87008699, -0.57580819, -0.17096189, 0.26671276, 0.65317284, 0.91420976, 0.99969882, 0.8932243, 0.61523159, 0.21910124, -0.21910124, -0.61523159, -0.8932243, -0.99969882, -0.91420976, -0.65317284, -0.26671276, 0.17096189, 0.57580819, 0.87008699, 0.99729046, 0.9329928, 0.68954054, 0.31368174, -0.12241068, -0.53499762, -0.84485357, -0.99247953, -0.94952818, -0.72424708, -0.35989504, 0.07356456, 0.49289819, 0.81758481, 0.98527764, 0.96377607, 0.75720885, 0.40524131, -0.02454123, -0.44961133, -0.78834643, -0.97570213],
[0.97003125, 0.74095113, 0.33688985, -0.14673047, -0.5956993, -0.90398929, -0.99879546, -0.85772861, -0.51410274, -0.04906767, 0.42755509, 0.80320753, 0.98917651, 0.94154407, 0.67155895, 0.24298018, -0.24298018, -0.67155895, -0.94154407, -0.98917651, -0.80320753, -0.42755509, 0.04906767, 0.51410274, 0.85772861, 0.99879546, 0.90398929, 0.5956993, 0.14673047, -0.33688985, -0.74095113, -0.97003125, -0.97003125, -0.74095113, -0.33688985, 0.14673047, 0.5956993, 0.90398929, 0.99879546, 0.85772861, 0.51410274, 0.04906767, -0.42755509, -0.80320753, -0.98917651, -0.94154407, -0.67155895, -0.24298018, 0.24298018, 0.67155895, 0.94154407, 0.98917651, 0.80320753, 0.42755509, -0.04906767, -0.51410274, -0.85772861, -0.99879546, -0.90398929, -0.5956993, -0.14673047, 0.33688985, 0.74095113, 0.97003125],
];

/**
* @var int
*/
private $size;
/**
* @var int[][]|float[][]
*/
private $dct11;
/**
* @var float
*/
private $sizeSqrt;

public function __construct(int $size = 32)
{
switch ($size) {
case 16:
$this->dct11 = self::DCT_11_16;
break;
case 32:
$this->dct11 = self::DCT_11_32;
break;
case 64:
$this->dct11 = self::DCT_11_64;
break;
default:
throw new LogicException('$size must be 16, 32 or 64');
}

$this->size = $size;
$this->sizeSqrt = sqrt(2 / $size);
}

public function hash(Image $image): Hash
{
// Resize the image.
$resized = $image->resize($this->size, $this->size);

$matrix = [];
$row = [];
$rows = [];
$col = [];

$matrixSize = 11;

for ($y = 0; $y < $this->size; $y++) {
for ($x = 0; $x < $this->size; $x++) {
$rgb = $resized->pickColor($x, $y);
$row[$x] = (int) floor(($rgb[0] * 0.299) + ($rgb[1] * 0.587) + ($rgb[2] * 0.114));
}
$rows[$y] = $this->calculateDCT($row, $matrixSize);
}

$rowMatrixSize = $matrixSize;

for ($x = 0; $x < $matrixSize; $x++) {
for ($y = 0; $y < $this->size; $y++) {
$col[$y] = $rows[$y][$x];
}
$matrix[$x] = $this->calculateDCT($col, $rowMatrixSize);
$rowMatrixSize--;
}

$pixels = $this->diagonalMatrix($matrix, $matrixSize);

$pixels = array_slice($pixels, 1, 64); // discard first and cut to size

$compare = $this->average($pixels);

// Calculate hash.
$bits = [];
foreach ($pixels as $pixel) {
$bits[] = (int) ($pixel > $compare);
}

return Hash::fromBits($bits);
}

/**
* Perform a 1 dimension Discrete Cosine Transformation.
*
* @param int[]|float[] $matrix
*
* @return float[]
*/
private function calculateDCT(array $matrix, int $partialSize): array
{
$dctCos = $this->dct11;
$transformed = [];

for ($i = 0; $i < $partialSize; $i++) {
$sum = 0;
for ($j = 0; $j < $this->size; $j++) {
$sum += $matrix[$j] * $dctCos[$i][$j];
}
$sum *= $this->sizeSqrt;
if ($i === 0) {
$sum *= 0.70710678118655;
}
$transformed[$i] = $sum;
}

return $transformed;
}

private function diagonalMatrix(array $mat, int $size = 11, bool $half = true)
{
$mode = 0;
$it = 0;
$lower = 0;
$result = [];
$max = ($half ? ceil((($size * $size) / 2) + ($size * 0.5)) : 0);
for ($t = 0; $t < (2 * $size - 1); $t++) {
$t1 = $t;
if ($t1 >= $size) {
$mode++;
$t1 = $size - 1;
$it--;
$lower++;
} else {
$lower = 0;
$it++;
}
for ($i = $t1; $i >= $lower; $i--) {
if ($half && count($result) >= $max) {
return $result;
}
if (($t1 + $mode) % 2 == 0) {
$result[] = $mat[$i][$t1 + $lower - $i];
} else {
$result[] = $mat[$t1 + $lower - $i][$i];
}
}
}

return $result;
}

/**
* Get the average of the pixel values.
*/
private function average(array $pixels): float
{
// Calculate the average value from top 8x8 pixels, except for the first one.
$n = count($pixels) - 1;

return array_sum(array_slice($pixels, 1, $n)) / $n;
}
}
4 changes: 4 additions & 0 deletions tests/ImplementationTest.php
View file
Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,7 @@
use Jenssegers\ImageHash\Implementations\BlockHash;
use Jenssegers\ImageHash\Implementations\DifferenceHash;
use Jenssegers\ImageHash\Implementations\PerceptualHash;
use Jenssegers\ImageHash\Implementations\PerceptualHash2;
use PHPUnit\Framework\TestCase;

class ImplementationTest extends TestCase
Expand All @@ -27,6 +28,9 @@ public function provideImplementations()
[new DifferenceHash()],
[new PerceptualHash(32, PerceptualHash::AVERAGE)],
[new PerceptualHash(32, PerceptualHash::MEDIAN)],
[new PerceptualHash2(16)],
[new PerceptualHash2(32)],
[new PerceptualHash2(64)],
[new BlockHash(8, BlockHash::QUICK)],
[new BlockHash(8, BlockHash::PRECISE)],
];
Expand Down

0 comments on commit 3ee829e

Please sign in to comment.