Free webp to jpg
Image MIME Reference
BTIF

Bank Telecommunications Image Format

image/prs.btif
VS

Windows Icon (Legacy MIME)

image/x-icon
ICO

A complete technical comparison of Bank Telecommunications Image Format and Windows Icon (Legacy MIME) — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

ICO wins on browser support

Feature Support

Feature BTIF ICO
Transparency (Alpha) ✕ No Yes
Animation Support ✕ No ✕ No
Progressive Loading ✕ No ✕ No
HDR Support ✕ No ✕ No
EXIF Metadata ✕ No ✕ No
ICC Color Profile ✕ No ✕ No
Bank Telecommunications Image Format
image/prs.btif
Extension
.btif.btf
Container Proprietary Check Image Container
Compression Lossy (JPEG-based) / Lossless (TIFF-based)
Algorithm
JPEGTIFF-variant
Color Depth 1-bit (B&W), 8-bit (Grayscale)
Developed by NationsBank (Bank of America) / Ben Simon
Released 1998
Magic Bytes
Unknown (Proprietary container)
Full BTIF reference →
Windows Icon (Legacy MIME)
image/x-icon
Extension
.ico
Container ICO Directory Structure
Compression Uncompressed (DIB/BMP) / Deflate (Embedded PNG)
Algorithm
NoneDeflate (via PNG)
Color Depth 1-bit, 4-bit, 8-bit, 24-bit (True Color), 32-bit (RGBA)
Developed by Microsoft Corporation
Released 1985
Magic Bytes
00 00 01 00
Full ICO reference →

Browser Support Comparison

Browser BTIF ICO
Chrome Chrome
✓ 1
Firefox Firefox
✓ 1
Safari Safari
✓ 1
Edge Edge
✓ 12
IE IE (Legacy)
BTIF

BTIF Strengths

  • Allowed early digital archiving and web-based transmission of cleared bank checks
  • Encapsulated both image data and ASCII transaction metadata in a single file
Limitations
  • Completely proprietary and obsolete format
  • Lacks native support in modern operating systems and image viewers
  • Requires legacy plugins or specialized bio-format readers (like ImageC) to decode
ICO

ICO Strengths

  • Universally supported by every web browser in existence for website favicons
  • Packs multiple resolutions into a single file, eliminating the need to serve different files for the taskbar vs. the desktop
  • Modern support for embedded PNGs (since Windows Vista) allows for excellent 32-bit transparency (alpha channels) and drastically reduced file sizes
Limitations
  • Internal file structure is convoluted due to decades of legacy cruft, such as the requirement for BMP data to lack a standard file header but double the height property for an archaic XOR/AND mask
  • Larger file size compared to a single optimized PNG or SVG, as it literally stores the same image multiple times at different scales
  • The MIME type landscape is highly fragmented (x-icon vs. vnd.microsoft.icon), causing occasional caching or strict-MIME validation errors on restrictive servers

When to choose which format

BTIF
Use BTIF when…
  • Bank Check Archiving (Legacy)
  • Financial Transaction Records
ICO
Use ICO when…
  • Website Favicons (favicon.ico)
  • Windows Application Executable Icons (.exe)
  • Desktop Shortcut Icons
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