OpenCV EAST Text detector implementation in Java
1
I am trying to convert the text detection example from the below page in Java. The original code is in C++.
https://github.com/opencv/opencv/blob/master/samples/dnn/text_detection.cpp
But I am facing issues in converting the below lines (131-136 in the cpp file) in Java:
...
const float* scoresData = scores.ptr<float>(0, 0, y);
const float* x0_data = geometry.ptr<float>(0, 0, y);
const float* x1_data = geometry.ptr<float>(0, 1, y);
...
I tried using every method from the openCV Mat class but most of them throw exceptions!
My code till now is as below:
Net net = Dnn.readNet("C:\frozen_east_text_detection.pb");
Mat blob = Dnn.blobFromImage(resizedImg, 1.0, resizedImg.size(), new Scalar(123.68, 116.78, 103.94), true,
false);
net.setInput(blob);
List<Mat> outs = new ArrayList<>();
net.forward(outs, LAYER_NAMES);
Mat scores = outs.get(0);
Mat geometry = outs.get(1);
int numRows = scores.size(2);
int numCols = scores.size(3);
List<RotatedRect> boxes = new ArrayList<>();
List<Double> confidences = new ArrayList<>();
System.out.printf("numRows = %dn", scores.size(2));
System.out.printf("numCols = %dn", scores.size(3));
I am not very familiar with pointers, but what I could understand is the scores native object seems to be a 4-D array, but it is a class in Java and there is no way in java to address a class with indices, like possible in C++ as shown, or in python as below (conversion of cpp program to python on another website):
for y in range(0, numRows):
scoresData = scores[0, 0, y]
xData0 = geometry[0, 0, y]
xData1 = geometry[0, 1, y]
xData2 = geometry[0, 2, y]
xData3 = geometry[0, 3, y]
anglesData = geometry[0, 4, y]
java opencv
asked Nov 20 at 21:46
inquizitive
359116
|
show 1 more comment
1
I am trying to convert the text detection example from the below page in Java. The original code is in C++.
https://github.com/opencv/opencv/blob/master/samples/dnn/text_detection.cpp
But I am facing issues in converting the below lines (131-136 in the cpp file) in Java:
...
const float* scoresData = scores.ptr<float>(0, 0, y);
const float* x0_data = geometry.ptr<float>(0, 0, y);
const float* x1_data = geometry.ptr<float>(0, 1, y);
...
I tried using every method from the openCV Mat class but most of them throw exceptions!
My code till now is as below:
Net net = Dnn.readNet("C:\frozen_east_text_detection.pb");
Mat blob = Dnn.blobFromImage(resizedImg, 1.0, resizedImg.size(), new Scalar(123.68, 116.78, 103.94), true,
false);
net.setInput(blob);
List<Mat> outs = new ArrayList<>();
net.forward(outs, LAYER_NAMES);
Mat scores = outs.get(0);
Mat geometry = outs.get(1);
int numRows = scores.size(2);
int numCols = scores.size(3);
List<RotatedRect> boxes = new ArrayList<>();
List<Double> confidences = new ArrayList<>();
System.out.printf("numRows = %dn", scores.size(2));
System.out.printf("numCols = %dn", scores.size(3));
I am not very familiar with pointers, but what I could understand is the scores native object seems to be a 4-D array, but it is a class in Java and there is no way in java to address a class with indices, like possible in C++ as shown, or in python as below (conversion of cpp program to python on another website):
for y in range(0, numRows):
scoresData = scores[0, 0, y]
xData0 = geometry[0, 0, y]
xData1 = geometry[0, 1, y]
xData2 = geometry[0, 2, y]
xData3 = geometry[0, 3, y]
anglesData = geometry[0, 4, y]
java opencv
asked Nov 20 at 21:46
inquizitive
359116
1
Maybe you couldreshapethoseMats it to get rid of the first two dimensions? Then it would be just some simple arithmetics to calculate the right position to read from. | It does seem that the Java bindings are somewhat limited regardingMats with more than 2 dimensions.
– Dan Mašek
Nov 20 at 22:22
Can you guide me a little? I am out of my depth here. What are channels, and what exactly does reshaping do?
– inquizitive
Nov 21 at 0:14
Channels, speaking about regularMatinstances, would refer to the third (implicit) dimension. For example, an RGB image is considered a 2dMatwith 3 channels. The two dimensions are width and height, and channels corresponding to the red, green and white components.
– Dan Mašek
Nov 21 at 0:34
Reshaping... the data of aMatis stored in a linear array (the details of the layout are in the C++ documentation). There's a header which contains the information about the "shape" (size of all the dimensions) which determines how coordinates map to the underlying data array. Best to make an example... imagine you have a RGB (3 channel) image with 10 rows and 10 columns. You can reshape this into a 1 channelMatwith 100 rows and 3 columns. The result has each pixel from the original per row, first column is Red and so on.
– Dan Mašek
Nov 21 at 0:43
1
It's a 100 mb file that I got from the below URL: bitbucket.org/tomhoag/opencv-text-detection/src/… . I uploaded it here just in case: gofile.io/?c=JkdZkN
– inquizitive
Nov 21 at 2:09
|
show 1 more comment
1
1
1
I am trying to convert the text detection example from the below page in Java. The original code is in C++.
https://github.com/opencv/opencv/blob/master/samples/dnn/text_detection.cpp
But I am facing issues in converting the below lines (131-136 in the cpp file) in Java:
...
const float* scoresData = scores.ptr<float>(0, 0, y);
const float* x0_data = geometry.ptr<float>(0, 0, y);
const float* x1_data = geometry.ptr<float>(0, 1, y);
...
I tried using every method from the openCV Mat class but most of them throw exceptions!
My code till now is as below:
Net net = Dnn.readNet("C:\frozen_east_text_detection.pb");
Mat blob = Dnn.blobFromImage(resizedImg, 1.0, resizedImg.size(), new Scalar(123.68, 116.78, 103.94), true,
false);
net.setInput(blob);
List<Mat> outs = new ArrayList<>();
net.forward(outs, LAYER_NAMES);
Mat scores = outs.get(0);
Mat geometry = outs.get(1);
int numRows = scores.size(2);
int numCols = scores.size(3);
List<RotatedRect> boxes = new ArrayList<>();
List<Double> confidences = new ArrayList<>();
System.out.printf("numRows = %dn", scores.size(2));
System.out.printf("numCols = %dn", scores.size(3));
I am not very familiar with pointers, but what I could understand is the scores native object seems to be a 4-D array, but it is a class in Java and there is no way in java to address a class with indices, like possible in C++ as shown, or in python as below (conversion of cpp program to python on another website):
for y in range(0, numRows):
scoresData = scores[0, 0, y]
xData0 = geometry[0, 0, y]
xData1 = geometry[0, 1, y]
xData2 = geometry[0, 2, y]
xData3 = geometry[0, 3, y]
anglesData = geometry[0, 4, y]
java opencv
asked Nov 20 at 21:46
inquizitive
359116
I am trying to convert the text detection example from the below page in Java. The original code is in C++.
https://github.com/opencv/opencv/blob/master/samples/dnn/text_detection.cpp
But I am facing issues in converting the below lines (131-136 in the cpp file) in Java:
...
const float* scoresData = scores.ptr<float>(0, 0, y);
const float* x0_data = geometry.ptr<float>(0, 0, y);
const float* x1_data = geometry.ptr<float>(0, 1, y);
...
I tried using every method from the openCV Mat class but most of them throw exceptions!
My code till now is as below:
Net net = Dnn.readNet("C:\frozen_east_text_detection.pb");
Mat blob = Dnn.blobFromImage(resizedImg, 1.0, resizedImg.size(), new Scalar(123.68, 116.78, 103.94), true,
false);
net.setInput(blob);
List<Mat> outs = new ArrayList<>();
net.forward(outs, LAYER_NAMES);
Mat scores = outs.get(0);
Mat geometry = outs.get(1);
int numRows = scores.size(2);
int numCols = scores.size(3);
List<RotatedRect> boxes = new ArrayList<>();
List<Double> confidences = new ArrayList<>();
System.out.printf("numRows = %dn", scores.size(2));
System.out.printf("numCols = %dn", scores.size(3));
I am not very familiar with pointers, but what I could understand is the scores native object seems to be a 4-D array, but it is a class in Java and there is no way in java to address a class with indices, like possible in C++ as shown, or in python as below (conversion of cpp program to python on another website):
for y in range(0, numRows):
scoresData = scores[0, 0, y]
xData0 = geometry[0, 0, y]
xData1 = geometry[0, 1, y]
xData2 = geometry[0, 2, y]
xData3 = geometry[0, 3, y]
anglesData = geometry[0, 4, y]
java opencv
java opencv
asked Nov 20 at 21:46
inquizitive
359116
asked Nov 20 at 21:46
inquizitive
359116
asked Nov 20 at 21:46
inquizitive
359116
asked Nov 20 at 21:46
inquizitive
359116
asked Nov 20 at 21:46
inquizitive
359116
359116
1
Maybe you couldreshapethoseMats it to get rid of the first two dimensions? Then it would be just some simple arithmetics to calculate the right position to read from. | It does seem that the Java bindings are somewhat limited regardingMats with more than 2 dimensions.
– Dan Mašek
Nov 20 at 22:22
Can you guide me a little? I am out of my depth here. What are channels, and what exactly does reshaping do?
– inquizitive
Nov 21 at 0:14
Channels, speaking about regularMatinstances, would refer to the third (implicit) dimension. For example, an RGB image is considered a 2dMatwith 3 channels. The two dimensions are width and height, and channels corresponding to the red, green and white components.
– Dan Mašek
Nov 21 at 0:34
Reshaping... the data of aMatis stored in a linear array (the details of the layout are in the C++ documentation). There's a header which contains the information about the "shape" (size of all the dimensions) which determines how coordinates map to the underlying data array. Best to make an example... imagine you have a RGB (3 channel) image with 10 rows and 10 columns. You can reshape this into a 1 channelMatwith 100 rows and 3 columns. The result has each pixel from the original per row, first column is Red and so on.
– Dan Mašek
Nov 21 at 0:43
1
It's a 100 mb file that I got from the below URL: bitbucket.org/tomhoag/opencv-text-detection/src/… . I uploaded it here just in case: gofile.io/?c=JkdZkN
– inquizitive
Nov 21 at 2:09
|
show 1 more comment
1
Maybe you couldreshapethoseMats it to get rid of the first two dimensions? Then it would be just some simple arithmetics to calculate the right position to read from. | It does seem that the Java bindings are somewhat limited regardingMats with more than 2 dimensions.
– Dan Mašek
Nov 20 at 22:22
Can you guide me a little? I am out of my depth here. What are channels, and what exactly does reshaping do?
– inquizitive
Nov 21 at 0:14
Channels, speaking about regularMatinstances, would refer to the third (implicit) dimension. For example, an RGB image is considered a 2dMatwith 3 channels. The two dimensions are width and height, and channels corresponding to the red, green and white components.
– Dan Mašek
Nov 21 at 0:34
Reshaping... the data of aMatis stored in a linear array (the details of the layout are in the C++ documentation). There's a header which contains the information about the "shape" (size of all the dimensions) which determines how coordinates map to the underlying data array. Best to make an example... imagine you have a RGB (3 channel) image with 10 rows and 10 columns. You can reshape this into a 1 channelMatwith 100 rows and 3 columns. The result has each pixel from the original per row, first column is Red and so on.
– Dan Mašek
Nov 21 at 0:43
1
It's a 100 mb file that I got from the below URL: bitbucket.org/tomhoag/opencv-text-detection/src/… . I uploaded it here just in case: gofile.io/?c=JkdZkN
– inquizitive
Nov 21 at 2:09
1
1
Maybe you could
reshape those Mats it to get rid of the first two dimensions? Then it would be just some simple arithmetics to calculate the right position to read from. | It does seem that the Java bindings are somewhat limited regarding Mats with more than 2 dimensions.– Dan Mašek
Nov 20 at 22:22
Maybe you could
reshape those Mats it to get rid of the first two dimensions? Then it would be just some simple arithmetics to calculate the right position to read from. | It does seem that the Java bindings are somewhat limited regarding Mats with more than 2 dimensions.– Dan Mašek
Nov 20 at 22:22
Can you guide me a little? I am out of my depth here. What are channels, and what exactly does reshaping do?
– inquizitive
Nov 21 at 0:14
Can you guide me a little? I am out of my depth here. What are channels, and what exactly does reshaping do?
– inquizitive
Nov 21 at 0:14
Channels, speaking about regular
Mat instances, would refer to the third (implicit) dimension. For example, an RGB image is considered a 2d Mat with 3 channels. The two dimensions are width and height, and channels corresponding to the red, green and white components.– Dan Mašek
Nov 21 at 0:34
Channels, speaking about regular
Mat instances, would refer to the third (implicit) dimension. For example, an RGB image is considered a 2d Mat with 3 channels. The two dimensions are width and height, and channels corresponding to the red, green and white components.– Dan Mašek
Nov 21 at 0:34
Reshaping... the data of a
Mat is stored in a linear array (the details of the layout are in the C++ documentation). There's a header which contains the information about the "shape" (size of all the dimensions) which determines how coordinates map to the underlying data array. Best to make an example... imagine you have a RGB (3 channel) image with 10 rows and 10 columns. You can reshape this into a 1 channel Mat with 100 rows and 3 columns. The result has each pixel from the original per row, first column is Red and so on.– Dan Mašek
Nov 21 at 0:43
Reshaping... the data of a
Mat is stored in a linear array (the details of the layout are in the C++ documentation). There's a header which contains the information about the "shape" (size of all the dimensions) which determines how coordinates map to the underlying data array. Best to make an example... imagine you have a RGB (3 channel) image with 10 rows and 10 columns. You can reshape this into a 1 channel Mat with 100 rows and 3 columns. The result has each pixel from the original per row, first column is Red and so on.– Dan Mašek
Nov 21 at 0:43
1
1
It's a 100 mb file that I got from the below URL: bitbucket.org/tomhoag/opencv-text-detection/src/… . I uploaded it here just in case: gofile.io/?c=JkdZkN
– inquizitive
Nov 21 at 2:09
It's a 100 mb file that I got from the below URL: bitbucket.org/tomhoag/opencv-text-detection/src/… . I uploaded it here just in case: gofile.io/?c=JkdZkN
– inquizitive
Nov 21 at 2:09
|
show 1 more comment
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1
Maybe you could
reshapethoseMats it to get rid of the first two dimensions? Then it would be just some simple arithmetics to calculate the right position to read from. | It does seem that the Java bindings are somewhat limited regardingMats with more than 2 dimensions.– Dan Mašek
Nov 20 at 22:22
Can you guide me a little? I am out of my depth here. What are channels, and what exactly does reshaping do?
– inquizitive
Nov 21 at 0:14
Channels, speaking about regular
Matinstances, would refer to the third (implicit) dimension. For example, an RGB image is considered a 2dMatwith 3 channels. The two dimensions are width and height, and channels corresponding to the red, green and white components.– Dan Mašek
Nov 21 at 0:34
Reshaping... the data of a
Matis stored in a linear array (the details of the layout are in the C++ documentation). There's a header which contains the information about the "shape" (size of all the dimensions) which determines how coordinates map to the underlying data array. Best to make an example... imagine you have a RGB (3 channel) image with 10 rows and 10 columns. You can reshape this into a 1 channelMatwith 100 rows and 3 columns. The result has each pixel from the original per row, first column is Red and so on.– Dan Mašek
Nov 21 at 0:43
1
It's a 100 mb file that I got from the below URL: bitbucket.org/tomhoag/opencv-text-detection/src/… . I uploaded it here just in case: gofile.io/?c=JkdZkN
– inquizitive
Nov 21 at 2:09