ImageCopy Question

[dweb]

Hi

 

I have a website that has a jQuery image dragger script, which lets you move an image up and down a fixed 500x800 area, the code ends up looking like;

 

<div style="width:500px; height:800px; overflow:hidden">
<div style="position: relative; top: -200px"><img width="500" src="images/test_image.jpg"></div>
</div>

 

This all works ok, and what i'm doing is then saving the css "top" value in my database.

 

In the example above, i'm saving -200 in the database.

 

I'm saving it because i might want to go back and adjust the image position later on

 

So my problem is, when I come to processing the image, I want to use

 

imagecopy();

 

to crop the image to the positioned sized

 

but when I pass my -200 value from the database

 

imagecopy(images/NEW_image.jpg, images/test_image.jpg, 0, 0, 0, -200, 500, 800);

 

it seems to crop the wrong way

 

how can I get PHP to correct that value so it crops correctly?

 

thanks

[jazzman1]

Where is your php script?

 

Also, what data type has this field in database when you try to save the negative value?

[dweb]

Hi Jazzman1

 

The type is int(5) and the record saves as "-200"

 

My PHP image processing code looks like;

 

$position = $rowdata['image_position'];
$src = imagecreatefromjpeg('images/saved_photo.jpg');
$dest = imagecreatetruecolor(500, 800);
imagecopy($dest, $src, 0, 0, 0, $position, 500, 800);
imagejpeg($dest,'images/copped_photo.jpg');
imagedestroy($dest);
imagedestroy($src);
 

 

The value $rowdata['image_position'] is the css top position that was saved (ie: -200)

 

thanks

[jazzman1]

Did you save the file to the right destination or not?

[dweb]

Yes, it all works fine, it's just that it -200 crops in the wrong direction

[jazzman1]

I've never use the imagecopy php function, but if you try to change -200 to +200, what's happening?

 

Do not remove the plus symbol. 

[kicken]

Having a negative crop setting doesn't make sense to me. Your crop rectangle should be within the bounds of the original image's size. The top should be between 0 and the original height, and the left should be between 0 and the original width.

 

If I am mis-understanding what it is you are attempting to do, you'll need to explain better, possibly with a visual aid.

[jazzman1]

I've made a simple test with a negative y-coordinate of source point value setting it to -200, and it works just fine.

 

Here it is:

 

 

 
<?php

// Create image instances

$src = imagecreatefromjpeg('images/12 Giulio Berruti picture.2.jpg');

$dest = imagecreatetruecolor(500, 800);

// Copy

imagecopy($dest, $src, 0, 0, 0, -200, 500, 800);

// Output the image

header('Content-Type: image/jpeg');

imagejpeg($dest,NULL, 90);

// free from memory

imagedestroy($dest);

imagedestroy($src);