For cropping images I am using CropImageView of joshholtz (https://github.com/joshdholtz/CropImageView). But I am getting IllegalArgumentException exception (saying: x + width must be <= bitmap.width()) at CreateBitmap function at crop function in the last line right before the return line.
public Bitmap crop(Context context) throws IllegalArgumentException {
// Weird padding cause image size
int weirdSidePadding = this.getWeirdSideMargin();
int weirdVerticalPadding = this.getWeirdVerticalMargin();
FrameLayout.LayoutParams params = (LayoutParams) mDaBox.getLayoutParams();
// Getting crop dimensions
float d = context.getResources().getDisplayMetrics().density;
int x = (int)((params.leftMargin - weirdSidePadding) * d);
int y = (int)((params.topMargin - weirdVerticalPadding) * d);
int width = (int)((this.getWidth() - params.leftMargin - params.rightMargin) * d);
int height = (int)((this.getHeight() - params.topMargin - params.bottomMargin) * d);
Bitmap crooopppppppppppppppeed = Bitmap.createBitmap(mBitmap, x, y, width, height);
return crooopppppppppppppppeed;
}
Actually I had a look at potentially same questions, but unluckily they are not same with my situation to the degree to help me.
Can you please help me to come over this barrier?
So in createBitmap, the function you're using creates a bitmap from a subsection of the original bitmap. For it to work, x+width may not be bigger than the width of the original bitmap (same for y+height) and x and y must both be >=0. This isn't the case here.
I think I get what this function is trying to do, but its just wrong. It seems to confuse the idea of cropping and scaling. If you want to scale and crop a bitmap at once, you should use the createBitmap(Bitmap source, int x, int y, int width, int height, Matrix m, boolean filter) with the scale factor in the matrix m. And I'm not sure you want to be scaling here at all- I don't know why the code is looking at the density, but its probably wrong to be doing so.
Related
In my app I need to let users to check the eyes at some photo.
In OnTouchListener.onTouch(...) I get the coordinates of the ImageView.
How can I convert this coordinates to the point at the bitmap that was touched?
this works for me at least with API 10+:
final float[] getPointerCoords(ImageView view, MotionEvent e)
{
final int index = e.getActionIndex();
final float[] coords = new float[] { e.getX(index), e.getY(index) };
Matrix matrix = new Matrix();
view.getImageMatrix().invert(matrix);
matrix.postTranslate(view.getScrollX(), view.getScrollY());
matrix.mapPoints(coords);
return coords;
}
Okay, so I've not tried this, but giving it a bit of thought, here's what I've got as a suggestion:
ImageView imageView = (ImageView)findViewById(R.id.imageview);
Drawable drawable = imageView.getDrawable();
Rect imageBounds = drawable.getBounds();
//original height and width of the bitmap
int intrinsicHeight = drawable.getIntrinsicHeight();
int intrinsicWidth = drawable.getIntrinsicWidth();
//height and width of the visible (scaled) image
int scaledHeight = imageBounds.height();
int scaledWidth = imageBounds.width();
//Find the ratio of the original image to the scaled image
//Should normally be equal unless a disproportionate scaling
//(e.g. fitXY) is used.
float heightRatio = intrinsicHeight / scaledHeight;
float widthRatio = intrinsicWidth / scaledWidth;
//do whatever magic to get your touch point
//MotionEvent event;
//get the distance from the left and top of the image bounds
int scaledImageOffsetX = event.getX() - imageBounds.left;
int scaledImageOffsetY = event.getY() - imageBounds.top;
//scale these distances according to the ratio of your scaling
//For example, if the original image is 1.5x the size of the scaled
//image, and your offset is (10, 20), your original image offset
//values should be (15, 30).
int originalImageOffsetX = scaledImageOffsetX * widthRatio;
int originalImageOffsetY = scaledImageOffsetY * heightRatio;
Give this idea a try and see if it works for you.
besides considering the offset due to padding (margin is part of the layout, it's space outside the view and doesn't have to be considered), if the image is scaled you can get the image matrix (ImageView.getImageMatrix()) to scale coordinates.
EDIT:
You can get x/y scaling factor and translation amount getting the values array and using respective index constants:
float[] values;
matrix.getValues(values);
float xScale = values[Matrix.MSCALE_X];
note that translation doesn't include padding, you still would have to consider that separately. translation is used for instance in FIT_CENTER scaling when there's some "blank" space.
I'd say you probably need to offset the coordinates from the ImageView with any padding or margins in the layout to get the correct coordinates of the BitMap.
To add to kcoppock's answer, I just want to add that:
//original height and width of the bitmap
int intrinsicHeight = drawable.getIntrinsicHeight();
int intrinsicWidth = drawable.getIntrinsicWidth();
may return an answer you're not expecting. These values depend on the dpi of the drawable folder you load the image from. For instance, you might get a different value if you load the image from /drawable vs /drawable-hdpi vs /drawable-ldpi.
Get floor Width and height
float floorWidth = floorImage.getWidth();
float floorHeight = floorImage.getHeight();
Calculate protionate value
float proportionateWidth = bitmapWidth / floorWidth;
float proportionateHeight = bitmapHeight / floorHeight;
Your X & Y
float x = 315;
float y = 119;
Multiple with PropotionateValue
x = x * proportionateWidth;
y = y * proportionateHeight;
As I came accross this question and tried it out myself, here is my solution.
It seems to work with stretched and centered images.
class MyEditableImageView(context: Context, attrs: AttributeSet) :
androidx.appcompat.widget.AppCompatImageView(context, attrs) {
override fun onTouchEvent(event: MotionEvent): Boolean {
val image = drawable.toBitmap().copy(Bitmap.Config.ARGB_8888, true)
val xp = (event.x - imageMatrix.values()[Matrix.MTRANS_X]) / imageMatrix.values()[Matrix.MSCALE_X]
val yp = (event.y - imageMatrix.values()[Matrix.MTRANS_Y]) / imageMatrix.values()[Matrix.MSCALE_Y]
if (xp >= 0 && xp < image.width && yp >= 0 && yp < image.height) {
doSomethingOnImage(image, xp, yp)
setImageBitmap(image)
}
return super.onTouchEvent(event)
}
...
}
It seems that setScaleX or setScaleY don't actually change left,top,right,bottom properties. getX and getY remain unchanged too.
So if I scale a view whats the easiest way to get 4 corner coordinates of the newly scaled view?
I tried getHitRect but that doesn't give me the right answer. I am trying to avoid manually calculating the new bounds based on existing transformations (rotation and scale with pivots factored in).
After exploring the view api, it looks like there is no direct API method that does this.
However you can easily get the new points by grabbing the transform matrix of the view and using that to get the new bounds.
Something like this:
Matrix m = view.getMatrix();
Rect bbox = new Rect();
view.getDrawingRect(bbox);
m.mapRect(bbox);
If you want to operate on (x,y) coordiantes directly there is a matrix.mapPoints that will achieve the same result.
I believe if you get the width and height and multiply it by the scales, you'll get the scaled width and height.
int scaledWidth = getWidth() * getScaleX();
int scaledHeight = getHeight() * getScaleY();
int newLeft = getLeft() + (scaledWidth / 2);
int newRight = newLeft + scaledWidth;
int newTop = getTop() + (scaledHeight / 2);
int newBottom = newTop + scaledHeight;
This is assuming that you scaled with a pivot x and y at the center of the view. Things gets far more complicated if you have pivots in strange areas.
I have an image of a face (250px X 250px) that is in an absolute layout element. I currently get the user's touch coordinates and using some maths calculate what has been touched (eg the nose), then do something accordingly.
My question is how to scale this to fit the screen width available. If I set the image (in the xml) to fill_parent, the coordinates are way out. Can this be remedied by converting the touch coordinates to dips (if so, how), or will I need to get the screen width (again convert into dips) and sort out the coordinate problem using more maths?
Any and all help appreciated.
pixels = dps * (density / 160)
The (density / 160) factor is known as the density scale factor, and get be retrieved in Java from the Display Metrics object. What you should do is store the position of the nose etc in terms of dips (which are the same as pixels on a screen with density 160), and then convert dips to pixels depending on what screen you are running on:
final static int NOSE_POSITION_DP = 10;
final float scale = getContext().getResources().getDisplayMetrics().density;
final int nosePositionPixels = (int) (NOSE_POSITION_DP * scale + 0.5f);
I have three useful functions in my library...
get Screen Density
public static float getDensity(Context context){
float scale = context.getResources().getDisplayMetrics().density;
return scale;
}
convert Dip to Pixels.
public static int convertDiptoPix(int dip){
float scale = getDensity();
return (int) (dip * scale + 0.5f);
}
convert Pixels to Dips.
public static int convertPixtoDip(int pixel){
float scale = getDensity();
return (int)((pixel - 0.5f)/scale);
}
A very simple way of doing this.
int value = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, 250, (mContext).getResources().getDisplayMetrics());
public int getDip(int pixel)
{
float scale = getBaseContext().getResources().getDisplayMetrics().density;
return (int) (pixel * scale + 0.5f);
}
In my app I need to let users to check the eyes at some photo.
In OnTouchListener.onTouch(...) I get the coordinates of the ImageView.
How can I convert this coordinates to the point at the bitmap that was touched?
this works for me at least with API 10+:
final float[] getPointerCoords(ImageView view, MotionEvent e)
{
final int index = e.getActionIndex();
final float[] coords = new float[] { e.getX(index), e.getY(index) };
Matrix matrix = new Matrix();
view.getImageMatrix().invert(matrix);
matrix.postTranslate(view.getScrollX(), view.getScrollY());
matrix.mapPoints(coords);
return coords;
}
Okay, so I've not tried this, but giving it a bit of thought, here's what I've got as a suggestion:
ImageView imageView = (ImageView)findViewById(R.id.imageview);
Drawable drawable = imageView.getDrawable();
Rect imageBounds = drawable.getBounds();
//original height and width of the bitmap
int intrinsicHeight = drawable.getIntrinsicHeight();
int intrinsicWidth = drawable.getIntrinsicWidth();
//height and width of the visible (scaled) image
int scaledHeight = imageBounds.height();
int scaledWidth = imageBounds.width();
//Find the ratio of the original image to the scaled image
//Should normally be equal unless a disproportionate scaling
//(e.g. fitXY) is used.
float heightRatio = intrinsicHeight / scaledHeight;
float widthRatio = intrinsicWidth / scaledWidth;
//do whatever magic to get your touch point
//MotionEvent event;
//get the distance from the left and top of the image bounds
int scaledImageOffsetX = event.getX() - imageBounds.left;
int scaledImageOffsetY = event.getY() - imageBounds.top;
//scale these distances according to the ratio of your scaling
//For example, if the original image is 1.5x the size of the scaled
//image, and your offset is (10, 20), your original image offset
//values should be (15, 30).
int originalImageOffsetX = scaledImageOffsetX * widthRatio;
int originalImageOffsetY = scaledImageOffsetY * heightRatio;
Give this idea a try and see if it works for you.
besides considering the offset due to padding (margin is part of the layout, it's space outside the view and doesn't have to be considered), if the image is scaled you can get the image matrix (ImageView.getImageMatrix()) to scale coordinates.
EDIT:
You can get x/y scaling factor and translation amount getting the values array and using respective index constants:
float[] values;
matrix.getValues(values);
float xScale = values[Matrix.MSCALE_X];
note that translation doesn't include padding, you still would have to consider that separately. translation is used for instance in FIT_CENTER scaling when there's some "blank" space.
I'd say you probably need to offset the coordinates from the ImageView with any padding or margins in the layout to get the correct coordinates of the BitMap.
To add to kcoppock's answer, I just want to add that:
//original height and width of the bitmap
int intrinsicHeight = drawable.getIntrinsicHeight();
int intrinsicWidth = drawable.getIntrinsicWidth();
may return an answer you're not expecting. These values depend on the dpi of the drawable folder you load the image from. For instance, you might get a different value if you load the image from /drawable vs /drawable-hdpi vs /drawable-ldpi.
Get floor Width and height
float floorWidth = floorImage.getWidth();
float floorHeight = floorImage.getHeight();
Calculate protionate value
float proportionateWidth = bitmapWidth / floorWidth;
float proportionateHeight = bitmapHeight / floorHeight;
Your X & Y
float x = 315;
float y = 119;
Multiple with PropotionateValue
x = x * proportionateWidth;
y = y * proportionateHeight;
As I came accross this question and tried it out myself, here is my solution.
It seems to work with stretched and centered images.
class MyEditableImageView(context: Context, attrs: AttributeSet) :
androidx.appcompat.widget.AppCompatImageView(context, attrs) {
override fun onTouchEvent(event: MotionEvent): Boolean {
val image = drawable.toBitmap().copy(Bitmap.Config.ARGB_8888, true)
val xp = (event.x - imageMatrix.values()[Matrix.MTRANS_X]) / imageMatrix.values()[Matrix.MSCALE_X]
val yp = (event.y - imageMatrix.values()[Matrix.MTRANS_Y]) / imageMatrix.values()[Matrix.MSCALE_Y]
if (xp >= 0 && xp < image.width && yp >= 0 && yp < image.height) {
doSomethingOnImage(image, xp, yp)
setImageBitmap(image)
}
return super.onTouchEvent(event)
}
...
}
for the sake of simplicity let's assume that I'm making a simple Pong clone game for Android. Let's assume that it would only be playable in the landscape mode. (ignore square phones for now).
I'd like the game to look in the same scale on each phone, to the extent that if you took a screenshot of the game on QVGA phone, and resized the screenshot to WVGA size, it would look almost the same as would the game look on WVGA phone. In other words, the paddle's width should always be 1/32 of the screen width, the ball's diameter should always be 1/16 of the screen width.
What would be the proper way to paint the application? It would run in standard SurfaceView that would be drawn onto a Canvas.
Let's say that I have a high-resolution PNGs for the paddle, ball and for the game font (scoreboard, main menu).
Do I find out the physical resolution, then scale the Canvas via scale(float sx, float sy) to make all my Canvases (on QVGA and WVGA) have the same virtual resolution, and then draw exactly the same primitives on each position on each screen size?
Or can I use density-independent pixels (dip) somehow in the Canvas?
I only played once with the draw canvas functions and then switched all to opengl but the logic stays the same (I think).
first issue you'll want to keep a ratio constant form one phone to the other.
in my app I add a " black band" effect on each side.
in onSurfaceChanged, you'll want to calculate a ratio, this ratio will allow you to determine how much space you have to remove on each side to keep a consistent aspect to your drawing. this will give you a delta X or Y to apply to all your draws
the following code is something I adapted from the ogl version so it might need to be tweeked a bit
#Override
public void onSurfaceChanged(int w, int h){
float ratioPhysicScreen = nativeScreenResoltionW/nativeScreenResoltionH;
float ratioWanted = GameView.getWidth()/GameView.getHeight();
if(ratioWanted>ratioPhysicScreen){
newHeight = (int) (w*GameView.getHeight()/GameView.getWidth());
newWidth = w;
deltaY = (int) ((h-newHeight)/2);
deltaX = 0;
}else{
newWidth = (int) (h/GameView.getHeight()*GameView.getWidth());
newHeight = h;
deltaX = (int) ((w-newWidth)/2);
deltaY = 0;
}
then you'll also want to be able to draw your pictures on the canvas by knowing there size as well on the canvas than there real size and that where the difference in between image.getWidth() (actual size of the picture) and a image.getScaledWidth(canvas) which give you the size of the element in dp which means how big it will appear on the screen) is important. look at the example underneath.
public class MainMenuView extends PixelRainView{
private Bitmap bmpPlay = null;
private float playLeft = 0;
private float playRight = 0;
private float playBottom = 0;
private float playTop = 0;
public MainMenuView(Context context, AttributeSet attrs) {
super(context,attrs);
}
#Override
public void unLoadBitmaps() {
super.unLoadBitmaps();
if(bmpPlay != null){
bmpPlay.recycle();
bmpPlay = null;
}
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if(bmpPlay == null){
bmpPlay = getBitmapFromRessourceID(R.drawable.play_bt);
playLeft = (this.getWidth()-bmpPlay.getScaledWidth(canvas))/2;
playRight = playLeft + bmpPlay.getScaledWidth(canvas);
playTop = (this.getHeight()-bmpPlay.getScaledHeight(canvas))/2;
playBottom = playTop+bmpPlay.getScaledHeight(canvas);
}
canvas.drawBitmap(bmpPlay,playLeft, playTop, null);
}
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
if(event.getAction() == MotionEvent.ACTION_DOWN){
float x = event.getX();
float y = event.getY();
//test central button
if(x>playLeft && x<playRight && y<playBottom && y>playTop){
Log.e("jason", "touched play");
PixelRainView.changeView(R.layout.composedlayoutgroup);
}
return super.onTouchEvent(event);
}
}
This should solve all your ratio problem cross plateforms
I would suggest opengl because it will simplify your need for keeping a constant aspect but I guess its not an option ^^
Hope this helps you enough
Use dips and paint the paddles instead of using PNGs
I think that there are only 3 standard resolutions available (ldip, mdip, hdip) and you should have a resource folder for each of them.
http://developer.android.com/guide/practices/screens_support.html
If you manually scale your PNG's to fit each of the 3 available resolutions, the phone should load the specific resource folder in a transparent way