在 GD 库中调整大小后裁剪图像

Question

我需要先按比例调整图像大小（宽度是重要的尺寸），然后裁剪以剪掉任何多余的高度，然后将新版本存储在目录中。

我已经成功地调整了大小，最终得到了目录中宽度正确的图像。在这里，我需要剪掉多余的高度。但我不知道我需要在哪里做。我是否需要以某种方式使用 copyimageresampled 。我想裁剪所有图像，使它们的高度为 50 像素。

这是我目前调整大小的内容：

$src = ImageCreateFromJpeg($upfile);
$dst = ImageCreateTrueColor($tn_width, $tn_height);
ImageCopyResized($dst, $src, 0, 0, 0, 0, $tn_width, $tn_height, $width, $height);
ImageJpeg($dst, 'images/' . $_FILES['image']['name']);

Answer 1

这就是我所追求的。一个2阶段的过程。诀窍是将图像调整为临时图像，然后对其进行裁剪：

http://salman-w.blogspot.com/2009/04/crop-to-fit-image-using-aspphp.html

Answer 2

这可能有助于您在调整大小后进行裁剪：911-need-code-help

<?php
  //----------------------------------------------------------------
  // Crop-to-fit PHP-GD
  // Revision 2 [2009-06-01]
  // Corrected aspect ratio of the output image
  //----------------------------------------------------------------

  define( 'DESIRED_IMAGE_WIDTH', 150 );
  define( 'DESIRED_IMAGE_HEIGHT', 150 );

  $source_path = $_FILES[ 'Image1' ][ 'tmp_name' ];

  //
  // Add file validation code here
  //

  list( $source_width, $source_height, $source_type ) = getimagesize( $source_path );

  switch ( $source_type )
  {
    case IMAGETYPE_GIF:
      $source_gdim = imagecreatefromgif( $source_path );
      break;

    case IMAGETYPE_JPEG:
      $source_gdim = imagecreatefromjpeg( $source_path );
      break;

    case IMAGETYPE_PNG:
      $source_gdim = imagecreatefrompng( $source_path );
      break;
  }

  $source_aspect_ratio = $source_width / $source_height;
  $desired_aspect_ratio = DESIRED_IMAGE_WIDTH / DESIRED_IMAGE_HEIGHT;

  if ( $source_aspect_ratio > $desired_aspect_ratio )
  {
    //
    // Triggered when source image is wider
    //
    $temp_height = DESIRED_IMAGE_HEIGHT;
    $temp_width = ( int ) ( DESIRED_IMAGE_HEIGHT * $source_aspect_ratio );
  }
  else
  {
    //
    // Triggered otherwise (i.e. source image is similar or taller)
    //
    $temp_width = DESIRED_IMAGE_WIDTH;
    $temp_height = ( int ) ( DESIRED_IMAGE_WIDTH / $source_aspect_ratio );
  }

  //
  // Resize the image into a temporary GD image
  //

  $temp_gdim = imagecreatetruecolor( $temp_width, $temp_height );
  imagecopyresampled(
    $temp_gdim,
    $source_gdim,
    0, 0,
    0, 0,
    $temp_width, $temp_height,
    $source_width, $source_height
  );

  //
  // Copy cropped region from temporary image into the desired GD image
  //

  $x0 = ( $temp_width - DESIRED_IMAGE_WIDTH ) / 2;
  $y0 = ( $temp_height - DESIRED_IMAGE_HEIGHT ) / 2;

  $desired_gdim = imagecreatetruecolor( DESIRED_IMAGE_WIDTH, DESIRED_IMAGE_HEIGHT );
  imagecopy(
    $desired_gdim,
    $temp_gdim,
    0, 0,
    $x0, $y0,
    DESIRED_IMAGE_WIDTH, DESIRED_IMAGE_HEIGHT
  );

  //
  // Render the image
  // Alternatively, you can save the image in file-system or database
  //

  header( 'Content-type: image/jpeg' );
  imagejpeg( $desired_gdim );

  //
  // Add clean-up code here
  //
?>

Answer 3

裁剪就像使用 GD 调整大小

一些示例代码：

// Original image
$filename = 'someimage.jpg';

// Get dimensions of the original image
list($current_width, $current_height) = getimagesize($filename);

// The x and y coordinates on the original image where we
// will begin cropping the image
$left = 50;
$top = 50;

// This will be the final size of the image (e.g. how many pixels
// left and down we will be going)
$crop_width = 200;
$crop_height = 200;

// Resample the image
$canvas = imagecreatetruecolor($crop_width, $crop_height);
$current_image = imagecreatefromjpeg($filename);
imagecopy($canvas, $current_image, 0, 0, $left, $top, $current_width, $current_height);
imagejpeg($canvas, $filename, 100);

您定义了裁剪宽度和高度，并且应该全部设置好。如您所见，它只不过是调整大小而已。

参考：http://www.johnconde.net/blog/cropping-an-image-with-php-and-the-gd-library/