Image effector

This is a simple demo of effect on images, made by Nick Antonaccio:

Here the source:

Rebol [
    title: "Image Effector"
    date: 29-june-2008
    file: %image-effector.r
    purpose: {
        A simple GUI demo application.  
        Taken from the tutorial at http://musiclessonz.com/rebol_tutorial.html
    }
]
filename: none
effect-types: ["Invert" "Grayscale" "Emboss" "Blur" "Sharpen" "Flip 1x1" "Rotate 90" "Tint 83" "Contrast 66" "Luma 150" "None"]
image-url: to-url request-text/title/default {Enter the url of an image to use:}   {http://rebol.com/view/demos/palms.jpg}
gui: [
    across
    space -1
    at 20x2 choice 160 tan
    "Save Image"
    "View Saved Image"
    "Download New Image"
    "-------------"
    "Exit" [   switch value [
        "Save Image" [
            filename: to-file request-file/title/file/save {Save file as:} "Save" %/c/effectedimage.png
            save/png filename to-image picture
            ]        
        "View Saved Image" [
            view-filename: to-file request-file/title/file   {View file:} "Save" filename
            view/new center-face layout [image load view-filename]
            ]
        "Download New Image" [
            new-image: load to-url request-text/title/default   {Enter a new image url}   {http://www.rebol.com/view/bay.jpg}
            picture/image: new-image
            show picture ; update the GUI display
            ]
        "-------------" [face/text: "Save Image" show face] ; don't do anything
        "Exit" [quit]      
        ]
    ]
    choice tan "Info" "About" [alert "Image Effector - Copyright 2005, Nick Antonaccio"]
    below
    space 5
    pad 2
    box 550x1 white
    pad 10
    vh1 "Click each effect in the list on the right:"    
    return
    across
    picture: image load image-url
    text-list data effect-types [
        current-effect: to-string value
        picture/effect: to-block form current-effect
        show picture
    ]
]
view/options center-face layout gui [no-title]