I am trying to grayscale bitmap as follows, But it is crashing as soon as I run this method.
The problem is in last line. How can I assign "int" to "Color"? Or are there any better ways?
CODE:................
View 9 Replies
I would like to convert a Bitmap to a grayscale array of bytes (one byte per pixel). At the same time I want to just crop at section from the middle. Having looked though the various api's it is not clear to me what the best way would be.
1) What is ALPHA_8? is that grayscale? I have a feeling that the grayscale effect should be done via some "saturation" on the paint object, right?
2) once I have the Bitmap in grayscale and the right size, what is the best way to get that to a byte[] of pixels (one byte per pixel)?
I am new to this site, and I come with a question about Android.
Is there any way to convert a Bitmap to grayscale? I know how to draw a grayscale bitmap (using canvas operations: http://www.mail-archive.com/android-developers@googlegroups.com/msg38890.html) but I really need The actual bitmap in gray colors (or at least something that could be converted to a bitmap later on).
Do I have to implement it by hand (pixel by pixel operations)?
I've searched a lot, and still could not find. Anyone knows a easy/efficient way to do it?
I've seen this code on the web...
My questions are:
1. Is 'bmp' supposed to be the color bitmap I want to affect?
2. How do I get the 0-255 value of the grayscale?
I have a very large image and I only want to display a section the size of the display (no scaling), and the section should just be the center of the image. Because the image is very large I cannot read the entire image into memory and then crop it. This is what I have so far but it will give OutOfMemory for large images. Also I don't think inSampleSize applies because I want to crop the image, not lower the resolution.
Uri data = getIntent().getData();
Input Stream is = getContentResolver().openInputStream(data);
Bitmap bitmap = BitmapFactory.decodeStream(is, null, null);
Any help would be great?
I am 1) taking a picture and 2) then draw another Bitmap on top of it 3) then I store it
I am doing it as follows and it works on the emulator.
On the device I get a OutOfMemoryError: bitmap size exceeds VM budget android.graphics.Bitmap.nativeCopy(Native Method) android.graphics.Bitmap.copy(Bitmap.java:199) in the line copy the Bitmap to get a mutable Bitmap.
CODE:...........
What I am asking:
a) Is there a better way to do what I am doing? 1) take a picture 2) draw another Bitmap on top of it 3) then I store it
b) What is the best way to create a mutable Bitmap from the picture I just took with the camera?
In my app, resolution is not an issue. If it works better for small photos that would be fine.
I have a camera application that captures a 640x480 image.I want to convert this image to grayscale.I know I have to use the setSaturatio (float sat) in the ColorMatrix method to zero but I don't know how I can set it to grayscale.
View 3 Replies View RelatedWhat would be the right way to turn a color Drawable into a grayscale one (to indicate disabled state)?
View 3 Replies View RelatedI am trying to use one of these algorithms to convert a RGB image to grayscale :
The lightness method averages the most prominent and least prominent colors:
(max(R, G, B) + min(R, G, B)) / 2.
The average method simply averages the values: (R + G + B) / 3.
The formula for luminosity is 0.21 R + 0.71 G + 0.07 B.
But i get very weird results ! I know there are other ways to achieve this but is it possible to do this way ?
here is the code...
I have two questions actually:
Is it better to draw an image on a bitmap or create a bitmap as resource and then draw it over a bitmap? Performance wise... which one is better?
If I want to draw something transparent over a bitmap, how would I go about doing it?
If I want to overlay one transparent bitmap over another, how would I do it?
My goal is the draw a bitmap onto another bitmap but rotated 90 degress. whats the most efficient way to do that. My current method is as follows which is horribly bad because it creates a new bitmap every time.
CODE:.....................
I am wondering how do I go about writing code (or be directed to any existing relevant code), that allows me to average the grayscale values above a threshold (Otsu threshold) from a JPEG photo taken from an android device camera.
View 2 Replies View RelatedWhat I am needing is a method to get grayscale pixel data from an image or preview. I am not interested in saving the picture as a jpeg etc, just need the grayscale data.
I am aiming at API 10 (as this is the device available for testing).
On top of this, I am not having any luck getting the camera to work on the Eclipse emulator.
I want to draw a shape(many circles particularly) into a Specific Bitmap. I have never used canvas / 2D graphs etc. As i see it i create a Drawable put the bitmap in it then "canvas-it" to the shapes i want etc.
View 1 Replies View RelatedI'm trying to figure out how to draw on a bitmap in android, and keep a copy of these changed bitmaps for an undo function.
Bitmap b = ...
Paint p = new Paint();
canvas.drawBitmap(b, new Matrix(), null);
canvas.drawCircle(0,0,20,20);
//does Bitmap b have the circle drawn on it next time?
Or how do I get the bitmap after its been drawn on with the canvas(I want to preserve a stack of bitmaps with the changes applied by canvas drawing)? Maybe I'm going about this entirely wrong.
I want to get the bitmap that is drawn when a textview is displayed but without displaying the textview in the activity. something like this:
TextView t = new TextView(this);
t.forceToDrawItself();
Bitmap b=t.getViewBitmap();
how is this possible?
Does anybody knows how can I put a Bitmap on top of a button, but without taking the whole surface?
View 2 Replies View RelatedI want to resize a bitmap and write to a file. what's the best way to do that?
View 2 Replies View RelatedI have two different bitmap. Can I merge these two bitmap into one?
View 7 Replies View RelatedI have a Bitmap image and i want to forward the bitmap to another activity. I have two activities Activity A and Activity B. This is how I started the Activity B
startActivityForResult(new Intent(Activity A.this, Activity B.class), 120);
in activity B
private void forwardImage(Bitmap bit) {
Intent i = new Intent(MMS.this, Compose.class);
i.putExtra("MMS", bit);
setResult(RESULT_OK, i);
finish(); }
This is not forwarding to Activity A but if I put a String to the intent it'll forward. This is how I listen to result in Activity A
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
// super.onActivityResult(requestCode, resultCode, data);
switch (resultCode)
case RESULT_OK: Intent intent = getIntent();
Bitmap bitmap = (Bitmap) intent.getParcelableExtra("MMS");
mmsImage.setImageBitmap(bitmap);
default: break;
} }
How can I pass a bitmap.
I have a bitmap displayed on ImageView now i want to give a facility to write comment typed by the user on that bitmap.i tried using Canvas canvas = new Canvas(srcBitmap); canvas.drawText("Hello", 100,100,null);but this is giving me following error java.lang.IllegalStateException: Immutable bitmap passed to Canvas constructor later on i want to save this whole image a bitmap.
View 1 Replies View RelatedIs there an easy way to replace a colour in a bitmap?
View 2 Replies View RelatedI have a picture taken using the phone's camera and in bitmap format. I want to send it over HTTP usinf Http post in ASCII.Any idea how to do it?
View 4 Replies View Relatedthis problem has been bothering me for days and I cannot figure out why on earth it is happening. I have a method that detects for a face, if a face is detected, the method will draw a rectangle on a canvas along the face.That part works fine.The problem is, when it displays to the image_view in my xml file, it will display on the far left middle of the image view, in a box, rather than in the center with the width as fill_parent.I thought of a possible workaround : to set the bitmap as a bitmapdrawable, but canvas only draws to bitmaps, so I can get the bitmapdrawable in the middle, but with no red box around it.I commented out my testing of bitmap drawable, and left it as what I have now...it only displays to my xml in the far left of the image_view.
View 1 Replies View Relatedmy app has widgets that have an ImageView and a TextView. On the onUpdate() method of the WidgetProvider, I put a Bitmap inside the ImageView this way:
CODE:..................
setColor() method is this:
CODE:..........
The problem is that sometimes the widget throws a RuntimeException because somebody has recycled the Bitmap, and I don't know what to do.
I have a long series of graphics -- icon1_0.png, icon1_1.png, icon1_2.png..., icon12_0.png, icon12_1.png, icon12_2.png -- and I'd like to package them with my android application. Ideally I think I should be able to load them as resources but the resource id's are set up as java identifiers. Of course, java identifiers can't be assembled at runtime. I have to ask for R.drawable.icon12_00 so I cannot set up a loop
for(int icon=0;icon<12;icon++)
for(int frame=0;frame<3;frame++)
//syntax error obviously
BitmapFactory.decodeResource(getResources(), R.drawable."icon" + icon + "_" + frame + ".png");
So is there any way to get resources by their names? Better yet, is there a canonical way outside the resource system to pack data files into an android application package so that I can get at them? I'm thinking about reflection but that doesn't seem like the right solution to me.
My program creates a bitmap and successfully stores it on external storage (Images.Media.EXTERNAL_CONTENT_URI).
The next option to implement is to share the image. I'm thinking about different way of doing it: 1. Save it as captured image (as before) and startActivity with Intent.ACTION_SEND intent with the saved image uri. 2. Save it in application's home directory (getFileStreamPath()), startActivityForResult as in 1. and I hope that I'll recieve a result when the message is sent. 3. Save it in some kind of temp/cache folder and don't bother about deleting it or delete it as in 2.
Personally I prefer the second option.
My questions are: Will it work with startActivityForResult() as in 2. ? Do I have access to temp/cache folder as in 3. ? If I do, Should I delete the file afterwards ? May be some flag for Intent.ACTION_SEND to delete the file afterwards ?
Can i draw text on a bitmap? I cannot find any API support this.
View 4 Replies View RelatedI have an application that uses GLSurfaceView to draw OpenGL ES graphics. This is all working (mostly) how I would expect.
Now, I would like to implement a screenshot feature. For normal views, it seems that the standard practice is to create a new Canvas with a Bitmap and then draw to that Canvas using View.onDraw(Canvas).
I've tried using SurfaceView.draw(Canvas) in a similar fashion, but it always results in a blank (black) image.
I've also tried using the drawing cache with the exact same result.
Any one know about how to draw a bitmap image?...
View 6 Replies View Related