The Signature Background Remover isolates handwritten pen ink from photograph or scan backgrounds, eliminating paper shadows, creases, and off-white discoloration to produce clean transparent PNG signatures.

### Pixel Luminance Segmentation Algorithm The cleaner processes uploaded signature images across an HTML5 2D canvas context: - Rec. 601 Luminance Extraction: Computes perceptual brightness for each RGB pixel: $$\text{Luminance} = 0.299 \times R + 0.587 \times G + 0.114 \times B$$ - Dynamic Alpha Masking: Compares pixel luminance against user-defined threshold sliders (default 140): - Paper Background ($\text{Luminance} > \text{Threshold}$): Sets alpha channel $A = 0$, rendering the background fully transparent. - Pen Stroke ($\text{Luminance} \le \text{Threshold}$): Sets alpha channel $A = 255$, preserving solid ink lines. - Ink Re-Coloring Mode: Allows normalizing inconsistent ballpoint pen ink to high-contrast executive black (`#0f0f14`) or deep legal royal blue (`#0a28b4`). - Clean PNG Export: Converts processed canvas data into a transparent PNG via native `canvas.toDataURL('image/png')`.

### Worked Cleaning Example - Input Image: Phone snapshot of a ballpoint signature on lined notebook paper ($1200 \times 600$ pixels with gray shadow). - Processing Settings: Luminance threshold set to 140, ink re-colored to Black. - Resulting Asset: Sharp, clean vector-like signature on an alpha-transparent canvas ready to stamp onto contracts in Adobe Acrobat or Google Docs.

### 100% In-Browser Image Processing Signature photos contain sensitive biometric identifiers. All image pixel decoding, thresholding, and PNG compilation execute locally in your browser memory with zero network uploads.