Method and apparatus for generating machining codes of workpieces from a paper engineering drawing

An apparatus for generating machining codes of workpieces from a paper engineering drawing, the machining codes indicating a dimension and shape of the workpieces, the apparatus comprising:

• a processor configured to execute computer-readable instructions such that, when executed by the computer, cause the computer to,
• process a photo of the paper engineering drawing captured by at least one imaging device to create a binary image,
• extract dimension features and shape features of the workpieces from the binary image, and
• generate the machining codes of the workpieces based on the extracted dimension features and shape features of the workpieces,
• wherein the processor is configured to execute computer-readable instructions to
• obtain a red, green, blue (RGB) image of the paper engineering drawing,
• convert the RGB image to a gray level image, and
• convert the gray level image to the binary image by comparing gray levels of pixels in the gray level image with a gray level threshold, configured to convert pixels with gray levels above the gray level threshold to pure black pixels and configured to convert pixels with gray levels below the gray level threshold to pure white pixels,
• wherein the processor is configured to execute computer-readable instructions to,
• identify dimension features of the workpieces from the binary image,
• remove the recognized dimension features from the binary image, and
• identify shape features of the workpieces from a remaining portion of the binary image after the recognized dimension features are removed,
• wherein the shape features of the workpieces include line functions and endpoints of segments, wherein an outline of at least one of the workpieces is divided into segments, and a line function of a segment is different from a line function of a neighboring segment.

A device for generating machining codes of workpieces from a paper engineering drawing, comprising:

• a storage to store executable instructions and
• a processor configured to execute the executable instructions stored in the storage to
• process a photo of the paper engineering drawing captured by at least one imaging device to create a binary image;
• extract dimension features and shape features of the workpieces from the binary image;
• and
• generate the machining codes of the workpieces based on the extracted dimension features and shape features of the workpieces,
• wherein the processing the photo of the paper engineering drawing comprises:
• obtaining a red, green, blue (RGB) image of the paper engineering drawing;
• converting the RGB image to a gray level image;
• converting the gray level image to the binary image by comparing gray levels of pixels in the gray level image with a gray level threshold, and converting pixels with gray levels above the gray level threshold to pure black pixels and converting pixels with gray levels below the gray level threshold to pure white pixels,
• wherein the extracting of the dimension features and shape features comprises:
• identifying dimension features of the workpieces from the binary image;
• removing the recognized dimension features from the binary image;
• and
• identifying shape features of the workpieces from a remaining portion of the binary image after the recognized dimension features are removed, and
• wherein the shape features of the workpieces include line functions and endpoints of segments, wherein an outline of a workpiece is divided into segments, and a line function of a segment is different from a line function of a neighboring segment.