I want to draw on a bitmap using another bitmap as mask. The mask is a black bitmap with a transparent object in it. I want this transparent part to be filled with an arbitrary color and added to my original image. How can this be done?
+
+ blue color =
I had to change the masks as described by #Christian. Then, the wanted result could easily be produced:
canvas.drawRect(rect, paint);
paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
canvas.drawBitmap(mask, 0.0f, 0.0f, paint);
If you're setting this to an ImageView, a quick way is to set the background to the gradient drawable, and a blue 'T' with a transparent background as the ImageView's source. Not fancy, but fast and simple!
Related
I have a custom view wich contain some bitmaps and I want to set shadows for them, for that, I use this code:
shadowPaints=new Paint(Paint.ANTI_ALIAS_FLAG);
shadowPaints.setShadowLayer(10.0f, 3.0f, 2.0f, Color.BLACK);
canvas.drawBitmap(bmp, matrix, shadowPaints);
setLayerType(LAYER_TYPE_SOFTWARE, shadowPaints);
and my result is
as you can see my shadow actually is another bitmap with different x and y position but what I want is my shadow be a solid color
bitmap.
can anyone help me about this?
setShadowLayer is actually meant for putting shadows on text.
If you already know the bitmap you want to draw, you can just add a shadow in PhotoShop and draw the bitmap and shadow all at once.
If you don't want to do that, you could make a shadow by making a copy of the image, using a PorterDuff filter to make it all grey, use Renderscript to blur the image, and draw it on the canvas at an x,y offset before drawing the actual image on top of it.
Personally, I think PhotoShop is a lot easier.
Good Morning,
I have an ImageView that I initialized with #99aaaaaa color (it corresponds to 153,170, 170,170). after that I draw some lines with different colors. and Now I want to Fill my Canvas with the original color (#99aaaaaa).
The method myCanvas.drawColor(OriginalColor) fills the canvas with OriginalColor, but the lines still visible
myPaint.setColor(OriginalColor);
myPaint.setStyle(Paint.Style.FILL);
myCanvas.drawRect(0, 0, 170, 170, myPaint); // my ImageView is 170X170
Also let lines visible.
Any help please, Thank You
as the canvas original color is semi transparent, then you draw something on it and draw another layer of semi transparent stuff, then its pretty obvious youll see the level-down-layer through the top transparent layer isnt it? another words, if you place a half transparent glass on your knees, ull still see the knees through it
Set the transfer mode as follows, before calling drawRec():
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC));
Reset the painter afterwards, for further drawing:
paint.setXfermode(null);
paint.setColor(0xFFFFFFFF);
Imagine that I have a rectangle image. How could I create a style like the next one?
I mean, cropping the image into a circle, add the border, the shadow and the gross /shine effect. Until now, I only have tried this snippet code to crop the image: Cropping circular area from bitmap in Android but just that. I have no idea how to do the remaining components in Android.
An easy way to achieve this effect is to use Canvas.drawCircle() and a BitmapShader:
BitmapShader s = new BitmapShader(myPhoto, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
Paint p = new Paint();
p.setShader(s);
myCanvas.drawCircle(centerX, centerY, radius, p);
To do the shadow, simply call Paint.setShadowLayer() on the paint (this will only work if you draw the effect into an offscreen Bitmap or if your View uses a software layer – set by calling View.setLayerType() –).
The border can be drawn by drawing another circle on top, using the Paint.Style.STROKE style (that you can set by calling Paint.setStyle()).
Finally you can draw the gloss by drawing a circle, oval or Path on top of your very first circle. You'll need to use a LinearGradient shader on your paint and you'll also need to clip the gloss. You can do this in two ways:
If you are drawing the entire effect into a Bitmap, which is what I would recommend, simply set the paint's Xfermode to a new PorterDuffXfermode(PorterDuff.Mode.SRC_IN).
If you are drawing the effect directly on screen you can simply use Canvas.clipPath() to set a circular clip. Note that this will work with hardware acceleration only as of Android 4.3.
I'm developing an android app where i need to capture text and save it as a transparent image. Capturing the text has been done but making a transparent png file is where i'm stuck as i'm not familiar with image pixel manipulation at all. Here's what I have so far... i first create a blank bitmap and fill it with a white background, then i set the paint's transparency to 0 (full transparency) and then draw the source bitmap into the destination bitmap using the XOR modes.. but when i run the app all i see is a blank white image. i'll be glad if someone points out what i'm doing wrong and how to fix it. Thanks in advance.
b = Bitmap.createBitmap(tw, th,Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(b);
Rect dest = new Rect(0,0,b.getWidth(),b.getHeight());
Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
paint.setColor(Color.WHITE);
canvas.drawRect(0, 0, b.getWidth(), b.getHeight(), paint);
paint.setAlpha(0);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.XOR));
canvas.drawBitmap(bmp,null,dest,paint);
Have you looked at : How to change a bitmap's opacity?
Seems like
paint.setAlpha(0);
won't do anything as you need to set the alpha channel to something greater than 0...
Use:
Color.argb(0,0,0,0)
The first parameter is the alpha. Set it to 0 for complete transparency.
I have a question about drawBitmap.
android.graphics.Canvas.drawBitmap(Bitmap bitmap, float left, float top, Paint paint)
What does that Paint paint? For example I have a picture.jpg and I make
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.picture);
paint = new Paint();
paint.setColor(Color.BLUE);
canvas.drawBitmap(bitmap, 0, 0, paint);
What can I do with that "paint" when I have a real picture not some canvas.drawCircle. Is there any way I can change pictures color or something like that?
Yes and another question. For example I draw circle in mspaint in 80x80 size and my background stays plain white. When I use that drawing in my program it shows circle + that white background. Is there any way that there will be displayed only circle without background. Maybe somebody can suggest some program in which I can make that happen or which code should I use in my program? (circle is just example, there can be anything)
Yes and excuse to use circle's background same as program's background is not appropriate, because my program's background isn't white or black or any other color, it is picture.
Paint objects can affect the rendering of the Bitmap. For example, they be used to mask the drawing of the Bitmap.
Save your circle as a PNG or GIF, and set the background as transparent (I do not know if MS Paint can do this).
i suggest gimp for image editing with transparency.
start a new image, delete the default layer, add a transparent layer, then paste your image over that. you can use the fuzzy select tool to trim any white space, then save as .png and you have a transparent image!