ImageWorkshop could be used as a layer.
A layer is a rectangle (or a square) which has a width and a height, and a background image having the same width and height. You can resize, crop, rotate, etc, a layer: its width and height and also its background image will be affected. This is how you rework your images.
By default, you can declare a virgin layer, which will have a transparent background like this:
$layer = ImageWorkshop::initVirginLayer(300, 200); // width: 300px, height: 200px
But this case is usefull only if you want to create and work on a new virgin image. In practice, you probably will create a layer from an existing image file:
$layer = ImageWorkshop::initFromPath('/path/to/images/picture.jpg');
By this way, your layer will automatically have the width and height of the image "picture.jpg", and its background will be this picture !
There are many ways to initialize a layer, just read the chapter "Layer".
You can perform an action on the layer, like resizing:
$thumbWidth = 125; $thumbHeight = 125; $layer->resizeInPixel($thumbWidth, $thumbHeight);
The layer will be resized (and so its background image) to have a width and a height of 125pixels.
Read chapter "Document" to discover all actions that you can perform on !
At everytime, you can access to the width and the height of a layer, usefull to know the new dimensions after a resize for example...:
$layer->getWidth(); // in pixel $layer->getHeight(); // in pixel
You can also get in pixel the narrow side or the largest side of your layer:
$layer->getNarrowSideWidth(); // in pixel $layer->getLargestSideWidth(); // in pixel
To show or to save the layer image, read the chapter "Group".
The power of a layer is not limited to that, you will learn in the next page how to use a layer as a group to superpose many layers (usefull to watermark a picture...).