Resize PNG and convert to jpeg - PNG32 gets a black backgroun

everything but png32s seem to work

[nigelt74]

Hi all

I have a project where i need to grab various images from a directory, resize them to a specific width and convert to jpeg then crop them to another size.

I have a script I have mashed together, which works with everything i have tried, except PNG32.

Unfortunately the person who this script is for uploads whatevr images their supplier sends them, and recently is seems to be PNG32s

When this runs through my script, it comes out with a black background.
Png8s and gifs all come through fine, this seems to be the part of the script where png32s are dealt with
or should I say the bit after the "elseif"

 if ( ($this->mime == 'image/gif') || ($this->mime == 'image/png') ) {
 $trnprt_indx = imagecolortransparent($this->src);
 // If we have a specific transparent color
 if ($trnprt_indx >= 0) {
echo 'tosspot7';// this works for gifs and png 8
 // Get the original image's transparent color's RGB values
 $trnprt_color = imagecolorsforindex($this->src, $trnprt_indx);
 
 // Allocate the same color in the new image resource
 $trnprt_indx = imagecolorallocate($this->tmp, $trnprt_color['red'], $trnprt_color['green'], $trnprt_color['blue']);
 
 // Completely fill the background of the new image with allocated color.
 imagefill($this->tmp, 0, 0, $trnprt_indx);
 
 // Set the background color for new image to transparent
 imagecolortransparent($this->tmp, $trnprt_indx);
 } 


 // Always make a transparent background color for PNGs that don't have one allocated already
 elseif ($this->mime == 'image/png') {
 echo 'tosspot3'; // PNG32 comes here bit fails
 
 // Turn off transparency blending (temporarily)
 imagealphablending($this->tmp, false);
 
 // Create a new transparent color for image
// $color = imagecolorallocatealpha($this->tmp, 0, 0, 0, 127);
 $color = imagecolorallocatealpha($this->tmp, 255, 255, 255, 127);
 
 // Completely fill the background of the new image with allocated color.
 imagefill($this->tmp, 0, 0, $color);
 
 // Restore transparency blending
 imagesavealpha($this->tmp, true);
 }
 }

as always anyhelp would be appreciated

[nigelt74]

Ok got it working, one line was missing from a script I copied
basically the last 4 lines above

// Restore transparency blending
imagesavealpha($this->tmp, true);
}
}

should be

// Restore transparency blending
imagesavealpha($this->tmp, true);
ImageAlphaBlending($this->tmp, true);
}
}

The comment mentioned it but somehow it didn't copy across.

[coopster]

Yep, that certainly makes it more difficult to troubleshoot. Glad you caught it!