cropRotateScaleImage
Extract an arbitrary geometry rectangular bitmap from the original bitmap.
The method can be used to crop and level the face image from the captured bitmap using MLKit face detection data as needed for further processing.
Usage Example
// Extract the square shaped face bitmap around the center point between eyes and level it by eyes line.
val faceCenterX = (leftEye.position.x + rightEye.position.x) / 2
val faceCenterY = (leftEye.position.y + rightEye.position.y) / 2
val eyeOffsetX = leftEye.position.x - rightEye.position.x
val eyeOffsetY = leftEye.position.y - rightEye.position.y
val eyeDistance = sqrt(eyeOffsetX * eyeOffsetX + eyeOffsetY * eyeOffsetY)
val faceWidth = eyeDistance * 3 // Heuristic multiplier to fit the face normalized to the eyes pupilar distance.
val eyesAngleRad = atan2(eyeOffsetY, eyeOffsetX)
val eyesAngleDeg = eyesAngleRad * 180.0 / PI // Convert radians to degrees
// Call platform dependent bitmap transformation.
val croppedFaceImageBitmap = cropRotateScaleImage(
frameData = frameData, // Platform-specific image data.
cx = faceCenterX.toDouble(), // Point between eyes
cy = faceCenterY.toDouble(), // Point between eyes
angleDegrees = eyesAngleDeg, // Eyes line rotation.
outputWidth = faceWidth.toInt(), // Expected face width for cropping *before* final scaling.
outputHeight = faceWidth.toInt(),// Expected face height for cropping *before* final scaling.
targetWidth = 256 // Final square image size (for database saving and face matching tasks).
)Return
An ImageBitmap representing the rotated, cropped, and scaled image.
Parameters
The camera frame data containing the original platform image bitmap reference and data.
The x-coordinate of the transformations center point in the original image (new image center).
The y-coordinate of the transformations center point in the original image (new image center).
The angle of rotation in degrees around the center point.
The desired width of the output image.
The desired height of the output image.
The desired width of the final image after scaling.
Extract an arbitrary geometry rectangular bitmap from the original bitmap.
The method can be used to crop and level the face image from the captured bitmap using MLKit face detection data as needed for further processing.
Usage Example
// Extract the square shaped face bitmap around the center point between eyes and level it by eyes line.
val faceCenterX = (leftEye.position.x + rightEye.position.x) / 2
val faceCenterY = (leftEye.position.y + rightEye.position.y) / 2
val eyeOffsetX = leftEye.position.x - rightEye.position.x
val eyeOffsetY = leftEye.position.y - rightEye.position.y
val eyeDistance = sqrt(eyeOffsetX * eyeOffsetX + eyeOffsetY * eyeOffsetY)
val faceWidth = eyeDistance * 3 // Heuristic multiplier to fit the face normalized to the eyes pupilar distance.
val eyesAngleRad = atan2(eyeOffsetY, eyeOffsetX)
val eyesAngleDeg = eyesAngleRad * 180.0 / PI // Convert radians to degrees
// Call platform dependent bitmap transformation.
val croppedFaceImageBitmap = cropRotateScaleImage(
frameData = frameData, // Platform-specific image data.
cx = faceCenterX.toDouble(), // Point between eyes
cy = faceCenterY.toDouble(), // Point between eyes
angleDegrees = eyesAngleDeg, // Eyes line rotation.
outputWidth = faceWidth.toInt(), // Expected face width for cropping *before* final scaling.
outputHeight = faceWidth.toInt(),// Expected face height for cropping *before* final scaling.
targetWidth = 256 // Final square image size (for database saving and face matching tasks).
)Return
An ImageBitmap representing the rotated, cropped, and scaled image.
Parameters
The x-coordinate of the transformations center point in the original image (new image center).
The y-coordinate of the transformations center point in the original image (new image center).
The angle of rotation in degrees around the center point.
The desired width of the output image.
The desired height of the output image.
The desired width of the final image after scaling.