Package com.itextpdf.pdfocr.onnx.util

Class BufferedImageUtil

java.lang.Object
com.itextpdf.pdfocr.onnx.util.BufferedImageUtil
public final class BufferedImageUtil extends Object
Additional algorithms for working with BufferedImage.

  • Method Details

    • toBchwInput

      public static FloatBufferMdArray toBchwInput (Collection<BufferedImage> images, OnnxInputProperties properties)
      Converts a collection of images to a batched ML model input in a BCHW format with 1 or 3 channels. This does aspect-preserving image resizing to fit the input shape.
      Parameters:
      images - collection of images to convert to model input
      properties - model input properties
      Returns:
      batched BCHW model input MD-array

    • rotate

      public static BufferedImage rotate (BufferedImage image, TextOrientation orientation)
      Rotates image based on text orientation. If no rotation necessary, same image is returned.
      Parameters:
      image - image to rotate
      orientation - text orientation used to rotate the image
      Returns:
      new rotated image, or same image, if no rotation is required

    • extractBoxes

      public static List<BufferedImage> extractBoxes (BufferedImage image, Collection boxes)
      Extracts sub-images from an image, based on provided rotated 4-point boxes. Sub-images are transformed to fit the whole image without (in our use cases it is just rotation).
      Parameters:
      image - original image to be used for extraction
      boxes - list of 4-point boxes. Points should be in the following order: BL, TL, TR, BR
      Returns:
      list of extracted image boxes

    • calcOutputDimensions

      public static Dimensions2D calcOutputDimensions (Collection<BufferedImage> images, ImageResizeOptions resizeOptions)
      Based on the provided ImageResizeOptions, calculates the dimensions to which a batch of images should be scaled and padded.
      Parameters:
      images - batch of images to scale/pad
      resizeOptions - resize options to take into consideration for scaling/padding
      Returns:
      the calculated dimensions

    • calcOutputDimensions

      public static Dimensions2D calcOutputDimensions (BufferedImage image, ImageResizeOptions resizeOptions)
      Based on the provided ImageResizeOptions, calculates the dimensions of the output image, to where there original image should be scaled and placed with padding. The returned dimensions will always satisfy the minimum constraints. Maximum constraints will also be satisfied, if the dimension multiple is 1, but if it is greater, it may round up to be higher than maximum.
      Parameters:
      image - image, that will be scaled/padded
      resizeOptions - resize options to take into consideration for scaling/padding
      Returns:
      the calculated dimensions

    • truncateToRatio

      public static BufferedImage truncateToRatio (BufferedImage image, double ratioLimit)
      Truncates the input image, so that neither width/height, nor height/width ratios exceed the limit.

      If width/height ratio exceeds the limit, the image will be truncated on left and right equally.

      If height/width ratio exceeds the limit, the image will be truncated on top and bottom equally.

      Parameters:
      image - input image to truncate
      ratioLimit - target ratio limit
      Returns:
      the truncated image