Free webp to jpg
EN
Image MIME Reference
DPX

Digital Picture Exchange

image/dpx
VS

Windows Icon (Legacy MIME)

image/x-icon
ICO

A complete technical comparison of Digital Picture Exchange 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 DPX ICO
Transparency (Alpha) Yes Yes
Animation Support ✕ No ✕ No
Progressive Loading ✕ No ✕ No
HDR Support Yes ✕ No
EXIF Metadata ✕ No ✕ No
ICC Color Profile ✕ No ✕ No
Digital Picture Exchange
image/dpx
Extension
.dpx
Container DPX (SMPTE ST 268)
Compression Uncompressed / RLE (Rarely used)
Algorithm
Uncompressed
Color Depth 8-bit, 10-bit, 12-bit, 16-bit, 32-bit (Float)
Developed by SMPTE (Society of Motion Picture and Television Engineers)
Released 1994
Magic Bytes
53 44 50 58 (Big-endian) / 58 50 44 53 (Little-endian)
Full DPX 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 DPX ICO
Chrome Chrome
✕
✓ 1
Firefox Firefox
✕
✓ 1
Safari Safari
✕
✓ 1
Edge Edge
✕
✓ 12
IE IE (Legacy)
✕
✓
DPX

DPX Strengths

  • Industry standard for transferring uncompressed, high-fidelity film and VFX data
  • Rich industry-specific metadata including timecode, keykode, and film stock information
  • Supports logarithmic color spaces (LogC, Cineon) to preserve the massive dynamic range of film negatives
Limitations
  • Massive file sizes (e.g., a single 4K 10-bit frame is ~50MB, resulting in ~1.2GB per second at 24fps)
  • Zero native support in web browsers or consumer OS image viewers
  • Requires heavy-duty, fast storage infrastructure (RAID/NVMe) to playback in real-time
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

DPX
Use DPX when…
  • Film Scanning
  • Visual Effects (VFX)
  • Digital Intermediate (DI)
  • Color Grading
  • Archival
ICO
Use ICO when…
  • Website Favicons (favicon.ico)
  • Windows Application Executable Icons (.exe)
  • Desktop Shortcut Icons

More comparisons

DPX vs ACES → ICO vs ACES → DPX vs APNG → ICO vs APNG → DPX vs AVCI → ICO vs AVCI → DPX vs AVCS → ICO vs AVCS → DPX vs AVIF → ICO vs AVIF → All comparisons →
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