To save processed image by OpenGL ES, I made codes as follows. And it works well.
ByteBuffer bb = ByteBuffer.allocate(mWidth * mHeight * 4);
mGL.glReadPixels(0, 0, mWidth, mHeight, GL_RGBA, GL_UNSIGNED_BYTE, bb);
try {
TJCompressor tjCompressor = new TJCompressor(bb.array(), 0, 0, mWidth, 0, mHeight, TJ.PF_RGB);
tjCompressor.setJPEGQuality(100);
tjCompressor.setSubsamp(TJ.SAMP_444);
return tjCompressor.compress(0);
} catch (Exception e) {
e.printStackTrace();
}
After that, to get 24bit color information without alpha channel for saving memory and processing time, I changed the line #1 and #2 of the codes as follows.
ByteBuffer bb = ByteBuffer.allocate(mWidth * mHeight * 3);
mGL.glReadPixels(0, 0, mWidth, mHeight, GL_RGB, GL_UNSIGNED_BYTE, bb);
And then additionally, I removed EGL_ALPHA_SIZE
at mGL(GL10 instance)'s EGLConfig. And I passed GLES20.GL_RGB
as internal format parameter, when GLUtils.texImage2D() method is called.
However, the result indicates there is something wrong. The result image has only black color, and when I checked the data of bb
buffer after glReadPixels()
method calling, I found all data is zero. I need advice. Help, plz.