是否可以在显示之前处理camerax预览的数据？

Question

I would like to process the image that is displayed in preview and display display the processed version.

I've tried modifying it using the imageProxy in analyzer, but that does not seem to be doing anything.

I know that older camera apis are able to do it, but CameraX does not seem to have the apis.

Answer 1

No, this flow is not supported by cameraX. Actually, this use case has never been supported by any Android camera API. What you have to do, is create your own renderer (preferably, OpenGL), hide the native preview surface, and send the modified frames to your renderer.

Answer 2

Hope this will help:

        val mediaImage = imageProxy.image ?: return
        var bitmap = ImageUtils.convertYuv420888ImageToBitmap(mediaImage)

        val rotationDegrees = imageProxy.imageInfo.rotationDegrees

        val matrix = Matrix()
        matrix.postRotate(rotationDegrees.toFloat())

        bitmap =
            Bitmap.createBitmap(bitmap, 0, 0, mediaImage.width, mediaImage.height, matrix, true)
        val cropHeight = if (bitmap.width < previewView.width) {
            // if preview area larger than analysing image
            val koeff = bitmap.width.toFloat() / previewView.width.toFloat()
            previewView.height.toFloat() * koeff
        } else {
            // if preview area smaller than analysing image
            val prc = 100 - (previewView.width.toFloat() / (bitmap.width.toFloat() / 100f))
            previewView.height + ((previewView.height.toFloat() / 100f) * prc)
        }

        val cropTop = (bitmap.height / 2) - ((cropHeight) / 2)

        if (cropTop > 0) {
            Bitmap.createBitmap(bitmap, 0, cropTop.toInt(), bitmap.width, cropHeight.toInt())
                .also { process(it, imageProxy) }
        } else {
            imageProxy.image?.let { process(it, imageProxy) }
        }