Bulk Curve: High-Performance Batch Image Border & Corner Stylist for Designers

The Repetitive Busywork of Screenshot Preparation

Every app developer, UI designer, and content creator knows the excruciating friction of preparing marketing assets. You take 50 high-resolution phone screenshots and need to:

1. Round all four corners to match Apple or Google hardware aesthetics (Squircle / Continuous curvature).
2. Add a sleek 1px or 2px outline stroke border to prevent dark screenshots from bleeding into dark backgrounds.
3. Export crisp 32-bit PNGs with intact transparent alpha channels.

Doing this manually in desktop Photoshop or Figma for dozens of assets takes hours of tedious clicking.

Bulk Curve was built to annihilate this friction entirely: a high-speed batch image processing utility that styles hundreds of images in seconds right on your Android device.

Hardware-Accelerated 2D Canvas Pipeline

To process massive batches of 4K screenshots without stuttering or out-of-memory crashes, Bulk Curve utilizes hardware-accelerated Android Canvas rendering with PorterDuff compositing:

// Smooth anti-aliased corner mask using PorterDuff SRC_IN
val outputBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888)
val canvas = Canvas(outputBitmap)
val paint = Paint(Paint.ANTI_ALIAS_FLAG)
val rect = RectF(0f, 0f, width.toFloat(), height.toFloat())

// 1. Draw rounded rectangle mask
canvas.drawRoundRect(rect, cornerRadiusPx, cornerRadiusPx, paint)

// 2. Transfer image pixels into mask
paint.xfermode = PorterDuffXfermode(PorterDuff.Mode.SRC_IN)
canvas.drawBitmap(sourceBitmap, 0f, 0f, paint)

// 3. Draw border stroke if enabled
if (strokeWidthPx > 0) {
    val strokePaint = Paint(Paint.ANTI_ALIAS_FLAG).apply {
        style = Paint.Style.STROKE
        strokeWidth = strokeWidthPx
        color = strokeColor
    }
    canvas.drawRoundRect(rect, cornerRadiusPx, cornerRadiusPx, strokePaint)
}

Core Creative Features

• Batch Processing Engine: Select 5, 20, or 100 images simultaneously from your gallery. Every modification applies instantly across the entire batch.
• Fine-Grained Radius Control: Smoothly calibrate corner radius from subtle 8px micro-curves to bold 64px modern pill styles with real-time viewport feedback.
• Adaptive Border Framing: Apply custom border strokes with customizable colors, opacity, and padding offsets.
• Lossless 32-Bit Alpha Export: Preserves transparency with zero quality degradation or unwanted compression artifacts.

100% Offline & Instant Productivity

Bulk Curve runs entirely on-device with no account registration, zero upload queues, and zero ads interrupting your creative workflow. Whether preparing Google Play screenshots, Twitter case studies, or developer portfolios, Bulk Curve completes your workflow in seconds.