Embroidery File Info Reader

An embroidery machine file is a list of needle moves, not a picture. The reader decodes that list the way a machine would, one record at a time, and keeps a running position. Every time the needle goes down it counts a stitch; every move without stitching counts as a jump; every stop for a new needle counts as a color change. The width and height come from the lowest and highest stitch positions, so they describe the area that actually gets stitched.

Each format stores the moves differently, and the reader follows the published format descriptions:

• DST (Tajima): a 512-byte text header, then 3-byte records. Each record moves the needle in steps of 0.1 mm, up to 121 units, and two control bits mark it as a stitch, a jump or a color change. There is no trim command: trims are written as a short run of jumps, so the reader counts a run of three or more jumps as one trim. That threshold is a convention shared with our file converter, not part of the format, so treat the DST trim count as an estimate.
• PES (Brother): starts with a version string such as #PES0001 and a pointer to the PEC section. The PEC section holds the stitches, flagged as stitch, jump or trim, and one palette index per color block. The reader shows those colors.
• EXP (Melco): no header at all, only 2-byte stitch records with a control byte for jumps, color changes and trims. There are no colors and no label to read.
• EMB (Wilcom): not a stitch file at all, but not a closed box either. It is an OLE2 compound file, the same container Microsoft used for older Office documents, holding Wilcom's editable design objects. Two parts inside it are readable: a preview image, stored as zlib-compressed JPEG, and a standard property list carrying the stitch count, colours, size, trims and machine. The design objects are not, so the reader shows those numbers and that picture and stops there. It is the master file worth keeping, not the file a machine sews.
• JEF (Janome): a 116-byte binary header holding the date the file was written, the hoop it was saved for and the design extents, then one 4-byte thread number per color block, then 2-byte stitch records escaped with 0x80 for jumps, color changes and the end of the design. The thread numbers point into Janome's own thread range, so a JEF is the one common machine format that names its threads rather than only showing a color. Like DST it has no trim command, so trims are estimated from runs of jumps.

Worked example (a real header, read the way this tool reads it): the EduTech wiki publishes a sample DST header with LA:sequin3, ST: 685, CO: 1, +X: 270, -X: 270, +Y: 224 and -Y: 224. Adding the X extents gives 540 units of 0.1 mm, so the design is 54.0 mm (2.13 in) wide; the Y extents give 44.8 mm (1.76 in) high. CO: 1 means 1 color change, so 2 color blocks, and ST: 685 counts 685 records in total, including jumps and color changes, so the real stitch count is somewhat lower.