B4J Question Save images in 300 DPI

[xulihang]

I need to use tesseract to OCR images and it produces a better result if the DPI is 300.

Using B4XBitmap, I can only set the image quality. I wonder if there is a way to set DPI.

 

[xulihang]

Found this thread: https://www.b4x.com/android/forum/threads/image-quality.81892/#post-518730

If the DPI is just a metadata, I can just change the resolution.

For example, a 20x99 image in 72DPI becomes an 84x412 one in 300DPI.


The problem is that I don't know the DPI of the original image.

 

[xulihang]

I've made a wrapper of Apache Commons Imaging to read the DPI info: https://www.b4x.com/android/forum/threads/read-image-dpi-using-apache-commons-imaging.137270/