这篇文章主要介绍了PHP实现图片不变型裁剪及图片按比例裁剪的方法,涉及PHP裁剪缩略图的常用技巧,需要的朋友可以参考下。

本文实例讲述了PHP实现图片不变型裁剪及图片按比例裁剪的方法，分享给大家供大家参考，具体如下：

图片不变型裁剪

1. <?php
2. /**
3. * imageCropper
4. * @param string $source_path
5. * @param string $target_width
6. * @param string $target_height
7. */
8. function imageCropper($source_path, $target_width, $target_height){
9. $source_info = getimagesize($source_path);
10. $source_width = $source_info[0];
11. $source_height = $source_info[1];
12. $source_mime = $source_info['mime'];
13. $source_ratio = $source_height / $source_width;
14. $target_ratio = $target_height / $target_width;
15. if ($source_ratio > $target_ratio){
16. // image-to-height
17. $cropped_width = $source_width;
18. $cropped_height = $source_width * $target_ratio;
19. $source_x = 0;
20. $source_y = ($source_height - $cropped_height) / 2;
21. }elseif ($source_ratio < $target_ratio){
22. //image-to-widht
23. $cropped_width = $source_height / $target_ratio;
24. $cropped_height = $source_height;
25. $source_x = ($source_width - $cropped_width) / 2;
26. $source_y = 0;
27. }else{
28. //image-size-ok
29. $cropped_width = $source_width;
30. $cropped_height = $source_height;
31. $source_x = 0;
32. $source_y = 0;
33. }
34. switch ($source_mime){
35. case 'image/gif':
36. $source_image = imagecreatefromgif($source_path);
37. break;
38. case 'image/jpeg':
39. $source_image = imagecreatefromjpeg($source_path);
40. break;
41. case 'image/png':
42. $source_image = imagecreatefrompng($source_path);
43. break;
44. default:
45. return ;
46. break;
47. }
48. $target_image = imagecreatetruecolor($target_width, $target_height);
49. $cropped_image = imagecreatetruecolor($cropped_width, $cropped_height);
50. // copy
51. imagecopy($cropped_image, $source_image, 0, 0, $source_x, $source_y, $cropped_width, $cropped_height);
52. // zoom
53. imagecopyresampled($target_image, $cropped_image, 0, 0, 0, 0, $target_width, $target_height, $cropped_width, $cropped_height);
54. header('Content-Type: image/jpeg');
55. imagejpeg($target_image);
56. imagedestroy($source_image);
57. imagedestroy($target_image);
58. imagedestroy($cropped_image);
59. }
60. $filename = "8fcb7a0831b79c61.jpg";
61. imageCropper($filename,200,200);
62. ?>

图片按比例裁剪

1. <?php
2. /**
3. * imageZoom
4. * @param string $file
5. * @param double $zoom
6. */
7. function imageZoom($filename,$zoom=0.6){
8. //baseinfo
9. $sourceImageInfo = getimagesize($filename);
10. $sourceWidth = $sourceImageInfo[0];
11. $sourceHeight = $sourceImageInfo[1];
12. $sourceMine = $sourceImageInfo['mime'];
13. $sourceRatio = $sourceWidth/$sourceHeight;
14. $sourceX = 0;
15. $sourceY = 0;
16. //zoom
17. $targetRatio = $zoom;
18. //target-widht-height
19. $targetWidth = $sourceWidth*$targetRatio;
20. $targetHeight = $sourceHeight*$targetRatio;
21. //init-params
22. $sourceImage = null;
23. switch($sourceMine){
24. case 'image/gif':
25. $sourceImage = imagecreatefromgif($filename);
26. break;
27. case 'image/jpeg':
28. $sourceImage = imagecreatefromjpeg($filename);
29. break;
30. case 'image/png':
31. $sourceImage = imagecreatefrompng($filename);
32. break;
33. default:
34. return ;
35. break;
36. }
37. //temp-target-image
38. $tempSourceImage = imagecreatetruecolor($sourceWidth, $sourceHeight);
39. $targetImage = imagecreatetruecolor($targetWidth,$targetHeight);
40. //copy
41. imagecopy($tempSourceImage, $sourceImage, 0, 0, $sourceX, $sourceY, $sourceWidth, $sourceHeight);
42. //zoom
43. imagecopyresampled($targetImage, $tempSourceImage, 0, 0, 0, 0, $targetWidth, $targetHeight, $sourceWidth, $sourceHeight);
44. //header
45. header('Content-Type: image/jpeg');
46. //image-loading
47. imagejpeg($targetImage);
48. //destroy
49. imagedestroy($tempSourceImage);
50. imagedestroy($sourceImage);
51. imagedestroy($targetImage);
52. }
53. $filename = "8fcb7a0831b79c61.jpg";
54. imageZoom($filename);
55. ?>

希望本文所述对大家PHP程序设计有所帮助。