HRZ to RGBO Converter

Produce RGBO from HRZ — browser-based converter

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Data Safety First

All HRZ uploads are removed after processing. Converted RGBO output is deleted within 24 hours to protect your information.

Format Flexibility

HRZ to RGBO conversion opens new possibilities. Use your SSTV images in contexts where RGBO is the expected or required format.

Remote Processing

The heavy lifting of HRZ to RGBO conversion happens on cloud servers — your computer or phone stays fast and unaffected.

How to convert HRZ to RGBO

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose rgbo or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your rgbo file right afterwards

About formats

HRZ is a simple raster image format associated with slow-scan television (SSTV), a method of transmitting still images over radio frequencies used by amateur radio operators since the late 1950s when Copthorne Macdonald pioneered the technology. HRZ files store images at a fixed resolution of 256x240 pixels in raw RGB format, with each pixel represented as three bytes (red, green, blue) at 8 bits per channel, producing uncompressed files of exactly 184,320 bytes. The format has no header, no metadata, and no compression — the file is simply a sequential dump of raw pixel data in row-major order. This extreme simplicity reflects the format's origins in the amateur radio community, where SSTV images are transmitted as audio tones encoding luminance and chrominance values over narrow-bandwidth HF (shortwave) radio channels. The fixed 256x240 resolution corresponds to common SSTV transmission modes, and HRZ files serve as the digital capture or storage medium for received SSTV transmissions. One advantage is the format's zero-overhead structure: with no parsing, decompression, or metadata processing required, HRZ files can be read by any program capable of reading raw pixel data with known dimensions — a single function call in virtually any programming language. The format's connection to amateur radio SSTV culture is another notable aspect: HRZ files document a unique form of image communication where operators transmit photographs over thousands of miles using nothing but radio waves and audio encoding, a practice that continues today alongside digital modes. HRZ files can be opened by ImageMagick, GIMP, and specialized SSTV software.
Developer: SSTV Community
Initial release: 1985
RGBO is a raw pixel data format designation used by ImageMagick, the open-source image processing suite first released in 1990, representing images as a flat sequence of Red, Green, Blue, and Opacity (inverted alpha) sample values with no header, container, or compression. The RGBO channel ordering specifies that the fourth channel is opacity rather than alpha — where alpha represents transparency (0 = transparent, max = opaque), opacity represents the inverse (0 = opaque, max = transparent). This distinction matters in compositing pipelines where the mathematical convention for the fourth channel varies between systems: some compositing models work with alpha (transparency), while older conventions including portions of ImageMagick's internal processing historically used opacity. RGBO files contain raw sample data at a user-specified bit depth (8-bit, 16-bit, or floating-point per channel), with pixels stored in scanline order. Because there is no header, the image dimensions, bit depth, and endianness must be specified externally when reading the file — typically via ImageMagick command-line arguments. One advantage is direct compatibility with processing pipelines that use the opacity convention: RGBO eliminates the need for channel inversion when interfacing with systems that expect opacity rather than alpha, preventing subtle compositing errors that occur when transparency conventions are mixed. The format's raw-data nature provides another practical benefit — with no encoding overhead, RGBO data can be memory-mapped, processed with SIMD instructions, or piped between processes with minimal latency. RGBO is primarily used within ImageMagick processing chains and can be converted to any other format using ImageMagick's extensive format support.
Initial release: 1990

Frequently Asked Questions

Why convert HRZ to RGBO?

Most people lack software for HRZ. Converting to RGBO ensures your SSTV images are viewable everywhere — from phones to desktops.

What programs open RGBO?

Most image viewers and editors handle RGBO — Photoshop, GIMP, IrfanView, and built-in viewers on Windows, macOS, and Linux.

Does this work on mobile devices?

Yes — the converter runs in any web browser, so it works on phones, tablets, laptops, and desktops regardless of operating system.

Do I need HRZ software installed?

No — the converter processes HRZ entirely in the cloud. You do not need any amateur radio slow-scan television software on your device to convert.

Will my image lose quality?

Quality depends on the target format. RGBO lossless with opacity output preserves data within its format constraints — no unnecessary degradation occurs.

Can I batch convert HRZ to RGBO?

Yes — Convertio supports batch uploads. Add multiple HRZ images and convert them all to RGBO at once to speed up your workflow.