imageaffine

(PHP 5 >= 5.5.0)

imageaffine元の画像を、オプションのクリッピング領域を使ってアフィン変換した画像を返す

説明

resource imageaffine ( resource $image , array $affine [, array $clip ] )

警告

この関数は、 現在のところ詳細な情報はありません。引数のリストのみが 記述されています。

パラメータ

image

imagecreatetruecolor() のような画像作成関数が返す画像リソース。

affine

0 から 5 までのキーを持つ配列。

clip

キー "x"、"y"、"width" そして "height" を持つ配列。

返り値

アフィン変換した画像リソースを返します。失敗した場合に FALSE を返します。

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User Contributed Notes 3 notes

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1
abc at ed48 dot com
11 months ago
Here is an example, which performs a specific processing, every time it is executed:

<?php

if (!function_exists('imageaffine'))
{
echo
'FUNCTION NOT DEFINED IN THIS VERSION OF PHP';
exit;
}

$base_img = 'affine.png';

$tgt_img1 = 'triangle1.png';

$tgt_img2 = 'triangle2.png';

$arr_affine = [
[
1, 0, 0, 1, 0, 0 ],
[
1, 0, 0, 1, 150, 0 ],
[
1.2, 0, 0, 0.6, 0, 0 ],
[ -
1.2, 0, 0, -0.6, 0, 0 ],
[
1, 2, 0, 1, 0, 0 ],
[
2, 1, 0, 1, 0, 0 ],
[
cos(15), sin(15), -sin(15), cos(15), 0, 0 ],
[
cos(15), -sin(15), sin(15), cos(15), 0, 0 ]
];

$RSR_base = imagecreatetruecolor(400, 300);
$w = imagesx($RSR_base);
$h = imagesy($RSR_base);

$arr_clip = [ 'x' => 0, 'y' => 0, 'width' => $w, 'height' => $h ];

$fillcolor = imagecolorallocate($RSR_base, 0, 0, 0);

imagefill($RSR_base, 10,10, $fillcolor);

imagepng($RSR_base, $base_img);

$drawcolor = imagecolorallocate($RSR_base, 255, 0, 0); 

$triangle = [ 50, 50, 50, 150, 200, 150 ];
$points = 3;

imageantialias($RSR_base, 1);

$drawtriangle = imagefilledpolygon($RSR_base, $triangle, $points, $drawcolor);

imagepng($RSR_base, $tgt_img1);

$select = mt_rand(0, 7);

$RSRaff2 = imageaffine($RSR_base, $arr_affine[$select], $arr_clip);

imagepng($RSRaff2, $tgt_img2, 9);

?>

SUPPORT IMAGE<br><br>
<img src="<?php echo $base_img; ?>" alt="*" /><br><br>

BASE IMAGE<br><br>
<img src="<?php echo $tgt_img1; ?>" alt="*" /><br><br>

RESULT IMAGE<br><br>
<img src="<?php echo $tgt_img2; ?>" alt="*" />
up
1
abc at ed48 dot com
11 months ago
correcting:

c ) SCALE,

         $affine = [ M, 0, N, 1, 0, 0 ];

         equations remapping,
        
         x' = Mx + 0y + 0 = Mx
        
         y' = 0x + Ny = 0 = Ny
        
         Each point will stretch or compress its path, horizontally or vertically, according M and N; negative or positive values.
up
1
abc at ed48 dot com
11 months ago
AFFINE is a geometric transformation operation involving MATRICES, covering both, 2D and 3D environment.
Transformations are often used in linear algebra and computer graphics.

In geometric transformations of images, the pixel coordinate is mapped.

This means that, each pixel is localized by two coordinates, in the rectangular domain of the image.
Without going into more details about pixel mapping, let's get to what really matters: the AFFINE transformations.
There are several classes of pixel mapping, one is called "affine".
Affine transformations include: scaling, rotation, shearing and translation.

PHP 5.5.0+, like "libart", uses ARRAYS of six floating-point elements to do the job.

The AFFINE ARRAY, is defined like,

         $affine = [ a0, a1, b0, b1, a2, b2 ];
        
         where,
         a0, a1, b0, b1, a2, b2 are floating-point values.
                    
         represented by equations,
        
         x' = a0x + a1y + a2
                    
         y' = b0x + b1y + b2
        
a ) IDENTITY, no change made in the path of points,

         $affine = [ 1, 0, 0, 1, 0, 0 ];
        
         equations remapping,
        
         x' = 1x + 0y + 0 = x
        
         y' = 0x + 1y = 0 = y
        
b ) TRANSLATION,

         $affine = [ 1, 0, 0, 1, H, V ];

         equations remapping,
        
         x' = 1x + 0y + H = x + H
        
         y' = 0x + 1y = V = y + V
        
         Each point is moved H units horizontaly and V units verticaly.
        
c ) SCALE,

         $affine = [ i, 0, j, 1, 0, 0 ];

         equations remapping,
        
         x' = Mx + 0y + 0 = Mx
        
         y' = 0x + Ny = 0 = Ny
        
         Each point will stretch or compress its path, horizontally or vertically, according M and N; negative or positive values.
        
d ) SHEARING, parallel to x axis,

         $affine = [ 1, K, 0, 1, 0, 0 ];

         equations remapping,
        
         x' = 1x + Ky + 0 = x + Ky
        
         y' = 0x + 1y = 0 = y
        
    SHEARING, parallel to y axis,

         $affine = [ K, 0, 0, 1, 0, 0 ];

         equations remapping,
        
         x' = 1x + 0y + 0 = x
        
         y' = Kx + 1y = 0 = y + Kx
        
e ) ROTATION, clockwise,

         $affine = [ cos Ø, sin Ø, -sin Ø, cos Ø, 0, 0 ];

         equations remapping,
        
         x' =  x cos Ø + y sin Ø + 0 = x cos Ø + y sin Ø
        
         y' = -x sin Ø + y cos Ø = 0 = y cos Ø - x sin Ø
        
    ROTATION, conterclockwise,

         $affine = [ cos Ø, -sin Ø, sin Ø, cos Ø, 0, 0 ];

         equations remapping,
        
         x' =  x cos Ø - y sin Ø + 0 = x cos Ø - y sin Ø
        
         y' = x sin Ø + y cos Ø = 0 = y sin Ø - x cos Ø
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