Android YUV to grayscale performance optimization
I'm trying to convert an YUV image to grayscale, so basically I just need the Y values.
To do so I wrote this little piece of code (with frame being the YUV image):
imageConversionTime = System.currentTimeMillis();
size = frame.getSize();
byte nv21ByteArray = frame.getImage();
int lol;
for (int i = 0; i < size.width; i++) {
for (int j = 0; j < size.height; j++) {
lol = size.width*j + i;
yMatrix.put(j, i, nv21ByteArray[lol]);
}
}
bitmap = Bitmap.createBitmap(size.width, size.height, Bitmap.Config.ARGB_8888);
Utils.matToBitmap(yMatrix, bitmap);
imageConversionTime = System.currentTimeMillis() - imageConversionTime;
However, this takes about 13500 ms. I need it to be A LOT faster (on my computer it takes 8.5 ms in python) (I work on a Motorola Moto E 4G 2nd generation, not super powerful but it should be enough for converting images right?).
Any suggestions?
Thanks in advance.
android performance image-processing optimization asked Nov 27 '18 at 20:56
AntonAnton
197
add a comment |
I'm trying to convert an YUV image to grayscale, so basically I just need the Y values.
To do so I wrote this little piece of code (with frame being the YUV image):
imageConversionTime = System.currentTimeMillis();
size = frame.getSize();
byte nv21ByteArray = frame.getImage();
int lol;
for (int i = 0; i < size.width; i++) {
for (int j = 0; j < size.height; j++) {
lol = size.width*j + i;
yMatrix.put(j, i, nv21ByteArray[lol]);
}
}
bitmap = Bitmap.createBitmap(size.width, size.height, Bitmap.Config.ARGB_8888);
Utils.matToBitmap(yMatrix, bitmap);
imageConversionTime = System.currentTimeMillis() - imageConversionTime;
However, this takes about 13500 ms. I need it to be A LOT faster (on my computer it takes 8.5 ms in python) (I work on a Motorola Moto E 4G 2nd generation, not super powerful but it should be enough for converting images right?).
Any suggestions?
Thanks in advance.
android performance image-processing optimization asked Nov 27 '18 at 20:56
AntonAnton
197
Unless you want to dive into OpenGL shaders, take a look at Android RenderScript as the sample (RGB to greyscale RGB) is similar to what you want to do. Does require some familiarity with C as RenderScript is C99.
– Morrison Chang
Nov 27 '18 at 21:24
I will have a look at OpenGL. Thank you for your answer.
– Anton
Nov 28 '18 at 15:39
add a comment |
I'm trying to convert an YUV image to grayscale, so basically I just need the Y values.
To do so I wrote this little piece of code (with frame being the YUV image):
imageConversionTime = System.currentTimeMillis();
size = frame.getSize();
byte nv21ByteArray = frame.getImage();
int lol;
for (int i = 0; i < size.width; i++) {
for (int j = 0; j < size.height; j++) {
lol = size.width*j + i;
yMatrix.put(j, i, nv21ByteArray[lol]);
}
}
bitmap = Bitmap.createBitmap(size.width, size.height, Bitmap.Config.ARGB_8888);
Utils.matToBitmap(yMatrix, bitmap);
imageConversionTime = System.currentTimeMillis() - imageConversionTime;
However, this takes about 13500 ms. I need it to be A LOT faster (on my computer it takes 8.5 ms in python) (I work on a Motorola Moto E 4G 2nd generation, not super powerful but it should be enough for converting images right?).
Any suggestions?
Thanks in advance.
android performance image-processing optimization asked Nov 27 '18 at 20:56
AntonAnton
197
I'm trying to convert an YUV image to grayscale, so basically I just need the Y values.
To do so I wrote this little piece of code (with frame being the YUV image):
imageConversionTime = System.currentTimeMillis();
size = frame.getSize();
byte nv21ByteArray = frame.getImage();
int lol;
for (int i = 0; i < size.width; i++) {
for (int j = 0; j < size.height; j++) {
lol = size.width*j + i;
yMatrix.put(j, i, nv21ByteArray[lol]);
}
}
bitmap = Bitmap.createBitmap(size.width, size.height, Bitmap.Config.ARGB_8888);
Utils.matToBitmap(yMatrix, bitmap);
imageConversionTime = System.currentTimeMillis() - imageConversionTime;
However, this takes about 13500 ms. I need it to be A LOT faster (on my computer it takes 8.5 ms in python) (I work on a Motorola Moto E 4G 2nd generation, not super powerful but it should be enough for converting images right?).
Any suggestions?
Thanks in advance.
android performance image-processing optimization android performance image-processing optimization asked Nov 27 '18 at 20:56
AntonAnton
197
asked Nov 27 '18 at 20:56
AntonAnton
197
asked Nov 27 '18 at 20:56
AntonAnton
197
asked Nov 27 '18 at 20:56
AntonAnton
197
asked Nov 27 '18 at 20:56
AntonAnton
197
197
Unless you want to dive into OpenGL shaders, take a look at Android RenderScript as the sample (RGB to greyscale RGB) is similar to what you want to do. Does require some familiarity with C as RenderScript is C99.
– Morrison Chang
Nov 27 '18 at 21:24
I will have a look at OpenGL. Thank you for your answer.
– Anton
Nov 28 '18 at 15:39
add a comment |
Unless you want to dive into OpenGL shaders, take a look at Android RenderScript as the sample (RGB to greyscale RGB) is similar to what you want to do. Does require some familiarity with C as RenderScript is C99.
– Morrison Chang
Nov 27 '18 at 21:24
I will have a look at OpenGL. Thank you for your answer.
– Anton
Nov 28 '18 at 15:39
Unless you want to dive into OpenGL shaders, take a look at Android RenderScript as the sample (RGB to greyscale RGB) is similar to what you want to do. Does require some familiarity with C as RenderScript is C99.
– Morrison Chang
Nov 27 '18 at 21:24
Unless you want to dive into OpenGL shaders, take a look at Android RenderScript as the sample (RGB to greyscale RGB) is similar to what you want to do. Does require some familiarity with C as RenderScript is C99.
– Morrison Chang
Nov 27 '18 at 21:24
I will have a look at OpenGL. Thank you for your answer.
– Anton
Nov 28 '18 at 15:39
I will have a look at OpenGL. Thank you for your answer.
– Anton
Nov 28 '18 at 15:39
add a comment |
1 Answer
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First of all I would assign size.width and size.height to a variable. I don't think the compiler will optimize this by default, but I am not sure about this.
Furthermore Create a byte representing the result instead of using a Matrix.
Then you could do something like this:
int grayScalePixels = new int[size.width * size.height];
int cntPixels = 0;
In your inner loop set
grayScalePixels[cntPixels] = nv21ByteArray[lol];
cntPixels++;
To get your final image do the following:
Bitmap grayScaleBitmap = Bitmap.createBitmap(grayScalePixels, size.width, size.height, Bitmap.Config.ARGB_8888);
Hope it works properly (I have not tested it, however at least the shown principle should be applicable -> relying on a byte instead of Matrix)
answered Nov 27 '18 at 21:53
Rene FerrariRene Ferrari
1,5962821
add a comment |
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1 Answer
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active
oldest
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votes
First of all I would assign size.width and size.height to a variable. I don't think the compiler will optimize this by default, but I am not sure about this.
Furthermore Create a byte representing the result instead of using a Matrix.
Then you could do something like this:
int grayScalePixels = new int[size.width * size.height];
int cntPixels = 0;
In your inner loop set
grayScalePixels[cntPixels] = nv21ByteArray[lol];
cntPixels++;
To get your final image do the following:
Bitmap grayScaleBitmap = Bitmap.createBitmap(grayScalePixels, size.width, size.height, Bitmap.Config.ARGB_8888);
Hope it works properly (I have not tested it, however at least the shown principle should be applicable -> relying on a byte instead of Matrix)
answered Nov 27 '18 at 21:53
Rene FerrariRene Ferrari
1,5962821
add a comment |
First of all I would assign size.width and size.height to a variable. I don't think the compiler will optimize this by default, but I am not sure about this.
Furthermore Create a byte representing the result instead of using a Matrix.
Then you could do something like this:
int grayScalePixels = new int[size.width * size.height];
int cntPixels = 0;
In your inner loop set
grayScalePixels[cntPixels] = nv21ByteArray[lol];
cntPixels++;
To get your final image do the following:
Bitmap grayScaleBitmap = Bitmap.createBitmap(grayScalePixels, size.width, size.height, Bitmap.Config.ARGB_8888);
Hope it works properly (I have not tested it, however at least the shown principle should be applicable -> relying on a byte instead of Matrix)
answered Nov 27 '18 at 21:53
Rene FerrariRene Ferrari
1,5962821
add a comment |
First of all I would assign size.width and size.height to a variable. I don't think the compiler will optimize this by default, but I am not sure about this.
Furthermore Create a byte representing the result instead of using a Matrix.
Then you could do something like this:
int grayScalePixels = new int[size.width * size.height];
int cntPixels = 0;
In your inner loop set
grayScalePixels[cntPixels] = nv21ByteArray[lol];
cntPixels++;
To get your final image do the following:
Bitmap grayScaleBitmap = Bitmap.createBitmap(grayScalePixels, size.width, size.height, Bitmap.Config.ARGB_8888);
Hope it works properly (I have not tested it, however at least the shown principle should be applicable -> relying on a byte instead of Matrix)
answered Nov 27 '18 at 21:53
Rene FerrariRene Ferrari
1,5962821
First of all I would assign size.width and size.height to a variable. I don't think the compiler will optimize this by default, but I am not sure about this.
Furthermore Create a byte representing the result instead of using a Matrix.
Then you could do something like this:
int grayScalePixels = new int[size.width * size.height];
int cntPixels = 0;
In your inner loop set
grayScalePixels[cntPixels] = nv21ByteArray[lol];
cntPixels++;
To get your final image do the following:
Bitmap grayScaleBitmap = Bitmap.createBitmap(grayScalePixels, size.width, size.height, Bitmap.Config.ARGB_8888);
Hope it works properly (I have not tested it, however at least the shown principle should be applicable -> relying on a byte instead of Matrix)
answered Nov 27 '18 at 21:53
Rene FerrariRene Ferrari
1,5962821
answered Nov 27 '18 at 21:53
Rene FerrariRene Ferrari
1,5962821
answered Nov 27 '18 at 21:53
Rene FerrariRene Ferrari
1,5962821
answered Nov 27 '18 at 21:53
Rene FerrariRene Ferrari
1,5962821
1,5962821
add a comment |
add a comment |
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Unless you want to dive into OpenGL shaders, take a look at Android RenderScript as the sample (RGB to greyscale RGB) is similar to what you want to do. Does require some familiarity with C as RenderScript is C99.
– Morrison Chang
Nov 27 '18 at 21:24
I will have a look at OpenGL. Thank you for your answer.
– Anton
Nov 28 '18 at 15:39