我有一个位图显示在
。谢谢。
ImageView
中,我希望能够将图像的一定比例转换成黑白,而其他部分保留其颜色。例如,如果目标比例为60%,则图像将如下所示:![would look like this](https://istack.dev59.com/9lQu9.webp)
ImageView
中,我希望能够使图像的某个百分比变为黑白,并使其余部分保留颜色。例如,如果目标百分比是60%。单色
(即灰度
),而不是黑白。void doIt(ImageView image)
{
//get bitmap from your ImageView (image)
Bitmap originalBitmap = ((BitmapDrawable)image.getDrawable()).getBitmap();
int height = originalBitmap.getHeight();
int fortyPercentHeight = (int) Math.floor(height * 40.0 / 100.0);
//create a bitmap of the top 40% of image height that we will make black and white
Bitmap croppedBitmap = Bitmap.createBitmap(originalBitmap, 0, 0, originalBitmap.getWidth() , fortyPercentHeight );
//make it monochrome
Bitmap blackAndWhiteBitmap = monoChrome(croppedBitmap);
//copy the monochrome bmp (blackAndWhiteBitmap) to the original bmp (originalBitmap)
originalBitmap = overlay(originalBitmap, blackAndWhiteBitmap);
//set imageview to new bitmap
image.setImageBitmap(originalBitmap );
}
Bitmap monoChrome(Bitmap bitmap)
{
Bitmap bmpMonochrome = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bmpMonochrome);
ColorMatrix ma = new ColorMatrix();
ma.setSaturation(0);
Paint paint = new Paint();
paint.setColorFilter(new ColorMatrixColorFilter(ma));
canvas.drawBitmap(bitmap, 0, 0, paint);
return bmpMonochrome;
}
Bitmap overlay(Bitmap bmp1, Bitmap bmp2)
{
Bitmap bmp3 = bmp1.copy(Bitmap.Config.ARGB_8888,true);//mutable copy
Canvas canvas = new Canvas(bmp3 );
canvas.drawBitmap(bmp2, new Matrix(), null);
return bmp3 ;
}
croppedBitmap
需要为底部的60%。这一切都与坐标有关。我会给你一个起点Bitmap croppedBitmap = Bitmap.createBitmap(originalBitmap, 0, fortyPercentHeight, originalBitmap.getWidth() , originalBitmap.getHeight());
。 - Jon Goodwin