Quality setting for PNG output

[kulmjens]

Hi there,

I noticed, that the quality setting ist not used when the output file type is set to PNG.
This can be achived by changing line 484 of phpthumb.class.php

ImagePNG($this->gdimg_output);

to

ImagePNG($this->gdimg_output, null, $this->thumbnailQuality);

Other than for JPG the value of the quality can only be 0-9 or -1.
See also http://php.net/manual/en/function.imagepng.php

[JamesHeinrich]

You would appear to have an older copy of phpThumb, since that line is now line 476, but your idea is sound.
One thing to watch out for is that quality settings for ImagePNG is relatively now (PHP v5.1.2) so can only be conditionally used.
I have also added a little more checking to ensure that $this->thumbnailQuality is within the accepted range, otherwise a default value of 6 is used.

Fixed in 813c93a