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JavaFX create a new image from an existing one

In JavaFX u can create a new Image from a string(path), how would i go about creating a new Image from an existing javafx.scene.image.image?
as following:
Image image2 = new Image("my/res/flower.png", 100, 150, false, false);
But instead of the path an actual image object.
I want to change the size of the image.

There is typically no need to create a new Image instance in order to perform rescaling. The API allows you to view or draw scaled versions of an existing Image instance. For example, given
Image image = new Image("my/res/flower.png");
you can create an ImageView that displays a scaled version with
ImageView imageView = new ImageView(image);
imageView.setFitWidth(100);
imageView.setFitHeight(150);
or you can draw a scaled version to a canvas with
Canvas canvas = ... ;
GraphicsContext gc = canvas.getGraphicsContext2D();
gc.drawImage(image, 0, 0, image.getWidth(), image.getHeight(), 0, 0, 100, 150);

A late response, but since I ran into the same issue (I needed an Image to pass to setDragView() ), here is the solution I have implemented:
Image makeThumbnail(Image original) {
ImageView i = new ImageView(original);
i.setFitHeight(64); i.setFitWidth(64);
return i.snapshot(new SnapshotParameters(), new WritableImage(64, 64));
}

Scaling an Image and positioning it at 0,0 in WPF

I have created BitMapSource from a list of RGBA pixels:
BitmapSource bmp = BitmapSource.Create(imageStrideInPixels, height, 96, 96, PixelFormats.Bgra32, null, imageData, imageStrideInPixels * pixelWidth);
I then create an image from the BitMapSource:
// create image and set image as source
Image BmpImg = new Image();
BmpImg.SetValue(Canvas.ZIndexProperty, 0);
BmpImg.Width = imageScaleWidth;
BmpImg.Height = imageScaleHeight;
BmpImg.Source = bmp;
I then add the Image to the Canvas:
mycanvas.Width = imageScaleWidth;
mycanvas.Height = imageScaleHeight;
mycanvas.Children.Clear();
mycanvas.Children.Add(BmpImg);
Canvas.SetLeft(BmpImg, 0); // to set position (x,y)
Canvas.SetTop(BmpImg, 0);
The problem is that it is not getting scaled to imageScaleWidth and imageScaleHeight, and it is being displayed half way down the canvas.
Note, I was able to do this in Java SWT by:
imageData = imageData.scaledTo(imageScaleWidth, imageScaleHeight);
gc.drawImage(imageData, 0, 0);

You can scale your image using a ScaleTransform:
// scale the original bitmap source
var transformedBitmap = new TransformedBitmap(
bmp,
new ScaleTransform(
imageScaleWidth / (double) bmp.PixelWidth,
imageScaleHeight / (double) bmp.PixelHeight));
// create image and set image as source
Image bmpImg = new Image();
bmpImg.SetValue(Canvas.ZIndexProperty, 0);
bmpImg.Source = transformedBitmap;
mycanvas.Width = imageScaleWidth;
mycanvas.Height = imageScaleHeight;
mycanvas.Children.Clear();
mycanvas.Children.Add(bmpImg);
Note that your image will be positioned at offset 0, 0 by default.

Instead of this
mycanvas.Children.Add(BmpImg);
Try this
mycanvas.Background = new VisualBrush(BmpImg);
This should render properly.

Are you sure the image is half way down the canvas and not the canvas itself is centered in its parent? I tested it and it appears that you can control the canvas position by setting vertical/horizontal alignment on canvas' parent. And also it scales properly when using the code you provided. However I created a BitmapSource in a different way. I used the following code:
PngBitmapDecoder decoder = new PngBitmapDecoder(new Uri(#"..."), BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.Default);
BitmapSource bmp = decoder.Frames[0];

JavaFX ImageView memory leak

I work on image slide show application on JavaFX and after a while of working java crash with no free memory error.
In interface code I have:
image = new ImageView();
Group root = new Group(image);
imageScene = new Scene(root, height, width);
primaryStage.setScene(imageScene);
In background thread I set image source for image view:
...
Map<String, Image> imagesMap = new HashMap<>();
...
// Slide thread
if (!imagesMap.containsKey(item.File)) {
Image image = new Image(item.File);
imagesMap.put(item.File, image);
}
Image i = imagesMap.get(item.File);
image.setImage(i);
While app run(with params: -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -Xmx256m) memory allocated to java process always is increasing...

Reduce the image size using the below code
Image img = ic.getImage();
Image newimg = img.getScaledInstance(500, 700, java.awt.Image.SCALE_SMOOTH);
I am sure you are using the original image size in this app.

how to merge Android canvas?

I was wondering, how do I merge/join Android canvases. In the code below I have cnv_left which contains a left part of a button. cnv_center contains the center part. And cnv_text contains text.
What I need is to merge them all in cnv_joined , so that
cnv_left would go first.
then cnv_center.
cnv_text would be in center of cnv_center.
and a flipped cnv_left would be the last.
Here's my code so far:
public void drawButt()
{
float buttonScale = 1.0f; /// general button scale ratio
float buttonScaleCnt = 6.0f; /// button's center part stretch ratio
LinearLayout LinLay = (LinearLayout)findViewById(R.id.linearLayout1);
ImageView iv1 = new ImageView(this);
Bitmap bit_left = Bitmap.createBitmap(100, 100, Bitmap.Config.ARGB_8888);
Canvas cnv_left = new Canvas(bit_left);
cnv_left.scale(buttonScale,buttonScale);
SVG svg_left = SVGParser.getSVGFromResource(getResources(), R.raw.btleft);
Picture picture_left = svg_left.getPicture();
picture_left.draw(cnv_left);
Bitmap bit_center = Bitmap.createBitmap(100, 100, Bitmap.Config.ARGB_8888);
Canvas cnv_center = new Canvas(bit_center);
cnv_center.scale(buttonScaleCnt, buttonScale);
SVG svg_center = SVGParser.getSVGFromResource(getResources(), R.raw.btcnt);
Picture picture_cnt = svg_center.getPicture();
picture_cnt.draw(cnv_center);
Bitmap bit_text = Bitmap.createBitmap(100, 100, Bitmap.Config.ARGB_8888);
Canvas cnv_text = new Canvas(bit_text);
cnv_text.scale(buttonScale, buttonScale);
Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG); paint.setColor(Color.WHITE); paint.setTextSize(20);
cnv_text.drawText("R", 2, 30, paint);
Bitmap bit_joined = Bitmap.createBitmap(200, 200, Bitmap.Config.ARGB_8888);
Canvas cnv_joined = new Canvas(bit_joined);
/// somehow need to somehow join the above canvases into this cnv_joined...
iv1.setImageBitmap(bit_joined);
iv1.setPadding(5, 5, 5, 5);
LinLay.addView(iv1);
}
Any ideas? Oh, and one more thing, when I create empty bitmaps for my canvas ( Bitmap.createBitmap(100, 100... ), does it matter what size I give them? If yes, where should I get the correct sizes for them?
Thanks!

Size of Bitmaps matter. If you do Picture.draw to canvas smaller than Picture, image will be cropped to size of bitmap.
Call SVG.getBounds to get bounds and put them in Bitmap constructor.
To join Bitmaps together you have to draw bit_left, bit_center and bit_text on cnv_joined using drawBitmap.
Better way will be to draw SVGs and text directly on cnv_joined.

Setting transparency makes textures translucent

Ok, so my problem is that I have a plane in java3d that has a texture painted on it. This texture is a PNG with alpha transparency. When the scene is rendered the texture on the plane is partially translucent, as if it has some transparency over the entire image. I have played around with a variety of texture and transparency settings trying to get it to work
Appearance ap = new Appearance();
TextureLoader tl = new TextureLoader(textImage);
Texture tex = tl.getTexture();
TextureAttributes ta = new TextureAttributes();
ta.setTextureMode(TextureAttributes.MODULATE);
TransparencyAttributes transat = new TransparencyAttributes();
transat.setTransparencyMode(TransparencyAttributes.BLENDED);
transat.setTransparency(0f);
ap.setTextureAttributes(ta);
ap.setTexture(tex);
ap.setTransparencyAttributes(transat);
shape.setAppearance(ap);
Any help would be appreciated

If you don't want any transparency at all for any of your texture, try this:
TransparencyAttributes tAttr = new TransparencyAttributes();
tAttr.setTransparencyMode(NONE);
ap.setTransparencyAttributes(tAttr);