A method for automatic calibration of a needle position relative to a coordinate system of a sewing machine includes: controlling a X-Y table to move a pallet to bring a sheet under a needle, lowering the needle to penetrate the sheet to form a needle hole and raising the needle, controlling the X-Y table to move the pallet to bring a reference mark and the test hole into an FOV of an image capturing device, obtaining an image of the pallet which contains the reference mark and the needle hole, determining an amount of separation of the needle hole from the reference mark in the image, and calibrating the needle position relative to the coordination system based on the amount of separation thus determined and a reference distance.

A method of generating an image that shows an embroidery area in an embroidery frame for computerized embroidery includes: acquiring a first image of a calibration board that has multiple feature points forming a contour approximating an embroidery area defined by the embroidery frame; identifying the feature points of the calibration board in the first image to acquire multiple graphical feature points; acquiring a geometric curved surface that fits the graphical feature points and that includes multiple curved surface points; acquiring a second image in which the embroidery area of the embroidery frame is shown; and performing image correction on the second image based on the geometric curved surface to generate a corrected image.

A method of generating an image that shows an embroidery area in an embroidery frame for computerized embroidery includes: acquiring a first image of a calibration board that has multiple feature points forming a contour approximating an embroidery area defined by the embroidery frame; identifying the feature points of the calibration board in the first image to acquire multiple graphical feature points; acquiring a geometric curved surface that fits the graphical feature points and that includes multiple curved surface points; acquiring a second image in which the embroidery area of the embroidery frame is shown; and performing image correction on the second image based on the geometric curved surface to generate a corrected image.

A decoration pattern data generating apparatus includes: a controller, the controller being configured to control the decoration pattern data generating apparatus to select an embroidery pattern to be sewn, specify an outline of the embroidery pattern, based on embroidery pattern data for sewing the selected embroidery pattern; set an area outside the specified outline, as a decoration area; and generate decoration pattern data for sewing a decoration pattern in the set decoration area.

The present invention provides a sewing machine enabling to sew a high-quality pattern without using an embroidery frame. In a sewing machine 1, a pattern is sewn while a fabric 100 is fed in a sewing direction by a feed dog 2a. The sewing machine 1 has a fabric guide 14. The fabric guide 14 has a guide portion 16 which extends straight in a sewing direction to serve as a basis of a cloth feed in an amplitude direction of the needle. The carriage 10 makes the fabric guide 14 slide in the amplitude direction of the needle by a predetermined distance. Thus, the guide portion 16 serves as an index of the position of the fabric 100 to be located for sewing the next pattern line. Since the fabric 100 can be accurately located for sewing the next pattern line, high-quality pattern can be sewn.

The present invention provides a sewing machine enabling to sew a high-quality pattern without using an embroidery frame. In a sewing machine 1, a pattern is sewn while a fabric 100 is fed in a sewing direction by a feed dog 2a. The sewing machine 1 has a fabric guide 14. The fabric guide 14 has a guide portion 16 which extends straight in a sewing direction to serve as a basis of a cloth feed in an amplitude direction of the needle. The carriage 10 makes the fabric guide 14 slide in the amplitude direction of the needle by a predetermined distance. Thus, the guide portion 16 serves as an index of the position of the fabric 100 to be located for sewing the next pattern line. Since the fabric 100 can be accurately located for sewing the next pattern line, high-quality pattern can be sewn.

A method of generating an image that shows an embroidery area in an embroidery frame for computerized embroidery includes: acquiring a first image of a calibration board that has multiple feature points forming a contour approximating an embroidery area defined by the embroidery frame; identifying the feature points of the calibration board in the first image to acquire multiple graphical feature points; acquiring a geometric curved surface that fits the graphical feature points and that includes multiple curved surface points; acquiring a second image in which the embroidery area of the embroidery frame is shown; and performing image correction on the second image based on the geometric curved surface to generate a corrected image.

A method of generating an image that shows an embroidery area in an embroidery frame for computerized embroidery includes: acquiring a first image of a calibration board that has multiple feature points forming a contour approximating an embroidery area defined by the embroidery frame; identifying the feature points of the calibration board in the first image to acquire multiple graphical feature points; acquiring a geometric curved surface that fits the graphical feature points and that includes multiple curved surface points; acquiring a second image in which the embroidery area of the embroidery frame is shown; and performing image correction on the second image based on the geometric curved surface to generate a corrected image.

A method for automatic calibration of a needle position relative to a coordinate system of a sewing machine includes: controlling a X-Y table to move a pallet to bring a sheet under a needle, lowering the needle to penetrate the sheet to form a needle hole and raising the needle, controlling the X-Y table to move the pallet to bring a reference mark and the test hole into an FOV of an image capturing device, obtaining an image of the pallet which contains the reference mark and the needle hole, determining an amount of separation of the needle hole from the reference mark in the image, and calibrating the needle position relative to the coordination system based on the amount of separation thus determined and a reference distance.

A method for embroidering endless strips using an embroidery machine includes the following steps: Feeding a strip section of at least one upper strip to an embroidery area of an embroidery frame; introducing embroidery using at least one embroidery head onto the strip section of the upper strip within the embroidery area of the embroidery frame; feeding at least one lower strip to the embroidery area of the embroidery frame, which is placed below the upper strip; producing at least one connecting seam between the upper strip and the lower strip in a plane of the embroidery frame; and removing the finished strip comprising the embroidered strip and the lower strip sewn thereto.