image.hasAlpha() Method?

[MCTaylor17]

Is it possible to add a method for determining if a PNG has a transparency colour channel?

Creating alpha channels when none is required results in unnecessarily large images.

Ideally, the following could be used:

image.rgba( image.hasAlpha() );

This would either preserve the channel when used remove it when unecessary.

Alternatively you could use it to determine file types:

if ( image.hasAlpha() ) {
    file = "filename.png";
} else {
    file = "filename.jpg";
}

[oliver-moran]

For PNG images, you can save with an alpha channel or not using:

image.rgba(false).write("image-no-alpha.png");

Or is it that you want to detect of there are any non-opaque pixels and decide to save as a JPEG if there are none?

[iwsfg]

Or is it that you want to detect of there are any non-opaque pixels and decide to save as a JPEG if there are none?

This.

Seems like a good idea, I'll implement it this tomorrow.

[nickgrealy]

How's this going? Looking forward to this feature!

[hipstersmoothie]

Released in v0.4.0