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Core Image

Description

The Core Image library for NodeBox adds image manipulation to NodeBox. It's like having control over Photoshop through simple Python programming commands. Core Image is a Mac OS X specific framework available from Mac OS X 1.4 (Tiger) and up (Leopard, ...). Core Image uses hardware acceleration whenever possible. You can apply filters and transformations to images with a real-time and interactive response. And, since all of the image manipulations are stored in a script, the process is non-destructive. The source images remain unchanged. The script is a recipe you can reuse on different source images.

Download

downloadcoreimage.zip (1.4MB)
Last updated for NodeBox 1.9.5
Licensed under GPL
Author: Tom De Smedt

Documentation

 

How to get the library up and running

Put the coreimage library folder in the same folder as your script so NodeBox can find the library. It takes some time to load the library the first time.

coreimage = ximport("coreimage")

 

Creating a new canvas

The canvas() command returns a new, empty canvas. It takes two parameters: the width and height of the canvas. You can set an optional quality parameter to "high" to use 128-bit pixel depth but this is unnecessary in most cases. 

canvas = coreimage.canvas(150, 150)

 

Adding new layers to the canvas

A canvas is a container of many layers which you can position, scale , rotate, blend, filter, etc. You can create layers from image files, fill colors, linear or radial gradients, paths (ovals, text, ...), lists of pixels colors, another layer or canvas (i.e. a group of layers), or Quicktime movie frames.

 

canvas.append()

The canvas.append() method adds a new layer to the top of the canvas. It is placed at the center of the canvas by default. 

canvas.append(filename)
canvas.append(clr)
canvas.append(clr1, clr2, type="linear", spread=0.0)
canvas.append(path, background=None, fill=None, stroke=None, strokewidth=None)
canvas.append([clr1, clr2, clr3, ...], w, h)
canvas.append(layer)
canvas.append(canvas)
canvas.append(layer.render())
canvas.append(canvas.flatten())
canvas.append(open(filename).read())
canvas.append(movieframe)

 

Examples

Consider we have the following images, leaf.jpg and lily.tif.


leaf.jpg
lily.tif

Core Image can use JPEG, GIF, PNG and TIFF images. If you are using images with an alpha channel the best way to import them is as transparent TIFF and not as a PNG (which can have jagged edges in Core Image).

 

A canvas with two layers from image files is easy enough: 
l = canvas.append("leaf.jpg")
l = canvas.append("lily.tif")
canvas.draw()
The canvas.append() method has four ptional parameters: the x and y position in pixels and w and h dimensions in pixels. The command returns the layer object.
Opaque fill layers are created from a standard NodeBox color(). The layer will fill the entire canvas by default. 
l = canvas.append(color(1.0, 0.0, 0.5))
Paths from NodeBox can be transformed to a pixel layers as well. The canvas.append() method has optional path parameters: fill, background, stroke (black, transparent and transparent colors by default) and strokewidth. 
l = canvas.append(color(1.0, 0.0, 0.5))
font("Georgia-Italic", 40)
p = textpath("text", 0, 0)
l = canvas.append(p, fill=color(1))
Linear gradients can be defined as two colors: 
l = canvas.append(color(1), color(0))