Cool stuff Ross, whats the overhead like in terms of memory etc?
I might have a bit of time to put this into a module and stuff it on review
board.
Cheers, Tim
On 15 Jan 2010, at 15:03, Ross Mellgren wrote:
> According to Jon on the call, he said he was putting together just such a
> lift module (for image stuff), so I figured I'd toss this over in case it was
> of use to him in that module.
>
> If anyone else wants to use it independently, consider it a contribution to
> lift, and licensed the same way.
>
> -Ross
>
> On Jan 15, 2010, at 9:51 AM, Peter Robinett wrote:
>
>> Ross, this looks nice. Imagine resizing code is something that I've
>> personally had to do many times and is always annoying, so perhaps
>> this would make a good Lift module? Anyway, this is probably best
>> discussed on the main list...
>>
>> Peter
>>
>> On Jan 14, 3:01 am, Ross Mellgren <dri...@gmail.com> wrote:
>>> Oh I nearly forgot I said on the conference call the other day that I'd
>>> send the image resize code we built at work, in case it would be helpful.
>>> Here it is:
>>>
>>> import java.awt.{Graphics, RenderingHints, Transparency}
>>> import java.awt.geom.AffineTransform
>>> import java.awt.image.{AffineTransformOp, BufferedImage, ColorModel,
>>> IndexColorModel}
>>>
>>> /**
>>> * Helpers for manipulating images
>>> */
>>> object ImageHelpers
>>> {
>>> // Some code here omitted -- Ed.
>>>
>>> /** Rendering hints set up for the highest quality rendering */
>>> val highQualityHints = {
>>> val h = new RenderingHints(null)
>>> h.put(RenderingHints.KEY_ALPHA_INTERPOLATION,
>>> RenderingHints.VALUE_ALPHA_INTERPOLATION_QUALITY)
>>> h.put(RenderingHints.KEY_COLOR_RENDERING,
>>> RenderingHints.VALUE_COLOR_RENDER_QUALITY)
>>> h.put(RenderingHints.KEY_INTERPOLATION,
>>> RenderingHints.VALUE_INTERPOLATION_BICUBIC)
>>> h.put(RenderingHints.KEY_ANTIALIASING,
>>> RenderingHints.VALUE_ANTIALIAS_ON)
>>> h.put(RenderingHints.KEY_RENDERING,
>>> RenderingHints.VALUE_RENDER_QUALITY)
>>> h
>>> }
>>>
>>> // Some code here omitted -- Ed.
>>>
>>> /**
>>> * Resize an image of the given source type by the given ratios,
>>> properly handling GIF transparency, giving back the resized
>>> * image and the new image format type that should be used.
>>> *
>>> * The image type might change if the input type is an indexed color
>>> model, because it is a hard problem to choose an optimized
>>> * palette, and currently we don't. This function will return "png" as
>>> the new type in this case.
>>> *
>>> * If the input image is not using an indexed color model with
>>> transparency, then the target format and color model will be
>>> * identical to the source.
>>> */
>>> def resize(source: BufferedImage, inputFormat: String, dx: Double, dy:
>>> Double): (BufferedImage, String) = {
>>> var sourceColorModel = source.getColorModel
>>> val targetColorModel = source.getColorModel
>>> val standardColorModel = ColorModel.getRGBdefault
>>>
>>> val (targetWidth, targetHeight) = (((source.getWidth: Double) *
>>> dx).asInstanceOf[Int], ((source.getHeight: Double) * dy).asInstanceOf[Int])
>>>
>>> def resize(src: BufferedImage, dst: BufferedImage) {
>>> val g = dst.createGraphics
>>> try {
>>> g.setRenderingHints(highQualityHints)
>>> g.drawImage(src, new
>>> AffineTransformOp(AffineTransform.getScaleInstance(dx, dy),
>>> AffineTransformOp.TYPE_BICUBIC), 0, 0)
>>> } finally {
>>> g.dispose
>>> }
>>> }
>>>
>>> // GIF support in Java is very ornery. For GIFs we have to manually
>>> do the masking on input, and then just punt on outputting GIFs and instead
>>> output PNGs.
>>> if (sourceColorModel.isInstanceOf[IndexColorModel] &&
>>> sourceColorModel.hasAlpha &&
>>> sourceColorModel.getTransparency == Transparency.BITMASK &&
>>>
>>> sourceColorModel.asInstanceOf[IndexColorModel].getTransparentPixel >= 0) {
>>>
>>> val indexColorModel =
>>> sourceColorModel.asInstanceOf[IndexColorModel]
>>> val transparent =
>>> indexColorModel.getRGB(indexColorModel.getTransparentPixel)
>>>
>>> val masked = new BufferedImage(standardColorModel,
>>> standardColorModel.createCompatibleWritableRaster(source.getWidth,
>>> source.getHeight), standardColorModel.isAlphaPremultiplied, null)
>>> var w = masked.getWidth
>>> var h = masked.getHeight
>>>
>>> val buf = new Array[Int](w)
>>>
>>> var y = 0
>>> while (y < h) {
>>> source.getRGB(0, y, w, 1, buf, 0, 1)
>>>
>>> var x = 0
>>> while (x < w) {
>>> val c = buf(x)
>>> if (c == transparent) {
>>> buf(x) = 0
>>> }
>>> x += 1
>>> }
>>>
>>> masked.setRGB(0, y, w, 1, buf, 0, 1)
>>> y += 1
>>> }
>>>
>>> val resized = new BufferedImage(standardColorModel,
>>> standardColorModel.createCompatibleWritableRaster(targetWidth,
>>> targetHeight), standardColorModel.isAlphaPremultiplied, null)
>>> resize(masked, resized)
>>> (resized, "png")
>>> } else if (sourceColorModel.isInstanceOf[IndexColorModel]) {
>>> // The input color model is indexed, and we know we won't be
>>> able to generate a tolerable palette to make another indexed color model,
>>> so use sRGB and upgrade to PNG.
>>> val resized = new BufferedImage(standardColorModel,
>>> standardColorModel.createCompatibleWritableRaster(targetWidth,
>>> targetHeight), standardColorModel.isAlphaPremultiplied, null)
>>> resize(source, resized)
>>> (resized, "png")
>>> } else {
>>> val resized = new BufferedImage(targetColorModel,
>>> targetColorModel.createCompatibleWritableRaster(targetWidth, targetHeight),
>>> targetColorModel.isAlphaPremultiplied, null)
>>> resize(source, resized)
>>> (resized, inputFormat)
>>> }
>>> }
>>>
>>> }
>>>
>>> It isn't perhaps the ideal implementation, as mentioned in some of the
>>> comments, but perhaps Jon or others might find it useful in whole or part.
>>>
>>> -Ross
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