Farrakh Javed's profile - activity

This is not working for different size images.

Hi guys, I am merging two images, after merging foreground image have colored border which i don't want. I am using below code to merge background and foreground image.

public void overlayImage1(Mat background, Mat foreground,Mat output)//, Point location) { background.copyTo(output); Mat dst = new Mat(); Imgproc.resize(foreground, dst, background.size()); double alpha; for(int y = 0; y < background.rows() ; ++y) { for(int x = 0; x < background.cols() ; ++x) { double info[] = dst.get(y, x); alpha = info[3]; if(alpha>0) {
double infof[] = dst.get(y, x); output.put(y, x, infof); } } } }

Below is output image.

Okay, thanks.

I want png image with alpha channel that is very simple question. PNG is saved as RGB channels. Where is Alpha like in format RGBA?

I dont want to convert to gray scale, I want png format image, If we simply save jpg image to png format it is saved but without alpha channel. I need alpha channel in it. Can you tell me how to do that?

@berak Thanks, Let me try with this.

Hi guys, I'm trying to convert image from jpeg format to png format. I'm also trying to apply Alpha on image so png save imag must be with alpha channel. I am not able to execute this(result.push_back<mat>(mask);) line in the code successfully.

Mat jpegImageMat = Highgui.imread("mnt/sdcard/aaawatermark/bird.jpg");
Mat gray_image = new Mat(), mask = new Mat(), rgba_image = new Mat();
List<Mat> result = new ArrayList<Mat>();
Core.split(jpegImageMat, result);
Imgproc.cvtColor(jpegImageMat, gray_image, Imgproc.COLOR_BGR2RGBA);
Imgproc.threshold(gray_image, mask, 128, 255, Imgproc.THRESH_BINARY);
result.push_back<Mat>(mask);
Core.merge(result, rgba_image);
Highgui.imwrite("mnt/sdcard/aaawatermark1/rgba.png", rgba_image);

Anybody help me will be appreciated.

For CV_8UC3 it is working. I think i am missing alpha value, but don't know how to solve this.

After making change as you suggested, i lost my watermark image(above rotated image).

If i omit the colorScalar from Mat function, default black background is applied. I can see different colors in background if i change Scalar values.

targetSize = new Size(newWidthHeight[0], newWidthHeight[1]);

I'm doing this, but not getting transparency. targetSize = new Size(newWidthHeight[0], newWidthHeight[1]); Scalar colorScalar = new Scalar(125,125,200,0.6); targetMat = new Mat(targetSize, scaledImage.type(),colorScalar);

Thanks for the reply, Can you tell me how to pass this parameter to target mat?

Hi, I'm using this code to make image background transparent, but i'm not getting the background transparent.

Imgproc.warpAffine(targetMat, resultMat, rotImage, targetSize, Imgproc.INTER_CUBIC,        
Imgproc.BORDER_TRANSPARENT,new Scalar(255,255,255,0));

You are right. I'm using opencv4Adnroid library. so i think i am not able to do that.

Please reply as soon as possible. Thanks in advance.

I'm not able to convert to java code for alpha and tmp. Kindly tell me how aplha is populated?

Can you give me your java code to remove the block background.Very Thanks

Hi, I want to create an application in android using open cv. My application include's functions are given below:

1. Read image in any format (JPEG, PNG, GIFF) etc.
2. Rotate and scale image, save rotated and scaled image.
3. Create composite image means placing one image on another image and creating one image from them.
4. Place text on image and save that image with text.

I tried to implement these functionality using JMagick library but did not get any success. Kindly tell me that above functionalities are possible to implement in open cv for android. Thanks.