Resize an image stored in a DB prior to diplaying it on page

[bissatch]

Hi,

I have a collection of images stored in a DB. They are there for the
purpose of a news system. When the user views the homepage it will
diplay cropped versions of the news where the user will them click the
'read more' link to view the entire article. It will also display a
thumbnail of the article image. As the image is stored at its full
display size in the DB I need to be able to resize it before outputing
it.

To display the image I use a PHP file called 'imageviewer.php' and pass
the unique idetifier as a GET parameter. Once the correct image data
column field has been queried I use the following line to output it
within the <img> tag:
echo pg_unescape_bytea($imgdata); //PostgreSQL database
However, in this instance I need to be able to resize it to a thumbnail
image prior to outputting. How would I do this?

Cheers

Burnsy

[bissatch]

bi******@yahoo.co.uk wrote:

Hi,

I have a collection of images stored in a DB. They are there for the
purpose of a news system. When the user views the homepage it will
diplay cropped versions of the news where the user will them click the
'read more' link to view the entire article. It will also display a
thumbnail of the article image. As the image is stored at its full
display size in the DB I need to be able to resize it before outputing
it.

To display the image I use a PHP file called 'imageviewer.php' and pass
the unique idetifier as a GET parameter. Once the correct image data
column field has been queried I use the following line to output it
within the <img> tag:
echo pg_unescape_bytea($imgdata); //PostgreSQL database
However, in this instance I need to be able to resize it to a thumbnail
image prior to outputting. How would I do this?

Cheers

Burnsy

Ok, not many replies. Can anybody tell me how this might be done with
an image stored in a MySQL db if possible? Cheers

Burnsy

[Steve]

echo pg_unescape_bytea($imgdata); //PostgreSQL database However, in this instance I need to be able to resize it to a thumbnail
image prior to outputting. How would I do this?

First <http://www.php.net/manual/en/function.imagecreatefromstring.php>
then <http://www.php.net/manual/en/function.imagecopyresized.php> or
<http://www.php.net/manual/en/function.imagecopyresampled.php>, then
<http://www.php.net/manual/en/function.imagejpeg.php>, and finally
<http://www.php.net/manual/en/function.imagedestroy.php>.

---
Steve

[NC]

bi******@yahoo.co.uk wrote:

I need to be able to resize it to a thumbnail image
prior to outputting. How would I do this?

The easy answer is that you probably shouldn't do it at all.
Image resizing is a CPU-intensive process, so resizing should
be done once, when uploading the image to the server. The
resulting thumbnail would then be stored next to the full-size
image.

Also, the wisdom of storing images in databases is questionable.
If you have a PHP page with five images on it, every time someone
views it, six simultaneous connections to the database will be
opened.

For details on resizing, see documentation for imagecopyresized()
and imagecopyresampled() functions:

http://www.php.net/imagecopyresized
http://www.php.net/imagecopyresampled

Cheers,
NC

[Default User]

Steve wrote:

echo pg_unescape_bytea($imgdata); //PostgreSQL database

However, in this instance I need to be able to resize it to a
thumbnail image prior to outputting. How would I do this?

First
<http://www.php.net/manual/en/function.imagecreatefromstring.php>
then <http://www.php.net/manual/en/function.imagecopyresized.php> or
<http://www.php.net/manual/en/function.imagecopyresampled.php>, then
<http://www.php.net/manual/en/function.imagejpeg.php>, and finally
<http://www.php.net/manual/en/function.imagedestroy.php>.

Some implementations won't have the JPEG support compiled in. There's
sometimes a program on UNIX systems called convert that can do what's
needed.

http://www.die.net/doc/linux/man/man1/convert.1.html

Brian

[badr]

hi every body
while i see alot of image functions in php but really i ever use one,

[e-mail]

i may adivse you to store 2 things :

1- the path in the DB of the small and big images you may need one
field the (image_path) and the add the big images path programatically.

2- you need also to store the image or you may need to create your own
uploade system to uploade the images (big and small), so you need to
upload the image twice the (small & big).

if you store the image in the DB in binary format i think it take a
time to be load and if it is more than 100KB it may reduce the
execution of your web page.

check it

[Bugz]

A) You probably wouldn't want to store the image in th DB in the first
place
B) Since you've done that, save the image in the /tmp/ forlder after
reading it from the DB, resize that image and display it on the page.
C) If you plan on having lots of visualizations of the thumbnail,
you'll most probably want to save the image for future use... do this
by either :
1 - updating the DB with a pointer to the resized image
2 - Check if the file name of the thumbnail exists in a give Directory
before processing the image.

Preferably, you'd want to store a pointer in the DB of both the Thumb
and the main image.This way, you transfer less data between PHP and
MySQL, hence making your code quicker to execute.