GROB
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|released=~1990 | |released=~1990 | ||
}} | }} | ||
| − | '''GROB''' is a bi-level raster graphics format associated with HP-48 and HP-49 series calculators. | + | '''GROB''' is a (usually) bi-level raster graphics format associated with HP-48 and HP-49 series calculators. |
There are two ways to encode a GROB image: "binary" and "ASCII". Sometimes, GROB images are also [[ASCII Encoded HP 48 Object|ASC-encoded]]. | There are two ways to encode a GROB image: "binary" and "ASCII". Sometimes, GROB images are also [[ASCII Encoded HP 48 Object|ASC-encoded]]. | ||
| − | == Format == | + | == Format details == |
Binary format has an 18-byte header, followed by the pixel data. | Binary format has an 18-byte header, followed by the pixel data. | ||
| + | |||
| + | === Grayscale images === | ||
| + | Although the format only really supports bi-level images, some images are intended to be interpreted as grayscale with 2 bits/pixel (or perhaps more). The physical image consists of the bit-planes stacked vertically. Unfortunately, there does not seem to be any way to detect whether this is the case. | ||
== Identification == | == Identification == | ||
| − | A binary GROB file begins with " | + | A binary GROB file begins with "{{magic|HPHP48}}" or "{{magic|HPHP49}}", and has bytes {{magic|1E 2B}} at offset 8. |
| − | ASCII format apparently begins with " | + | ASCII format apparently begins with "{{magic|GROB }}". An ASCII GROB might be embedded inside a script, or preceded by a "{{magic|%%HP}}" header line, so it won't necessarily start at the beginning of the file. |
== Software == | == Software == | ||
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== Sample files == | == Sample files == | ||
=== Binary === | === Binary === | ||
| + | * http://cd.textfiles.com/hhot/CALCUL~5/HP48G/GRAPHICS/ ... | ||
* [http://cd.textfiles.com/blackphiles/PHILES/HP48_1/GROBS1.ZIP GROBS1.ZIP], [http://cd.textfiles.com/blackphiles/PHILES/HP48_1/GROBS2.ZIP GROBS2.ZIP] | * [http://cd.textfiles.com/blackphiles/PHILES/HP48_1/GROBS1.ZIP GROBS1.ZIP], [http://cd.textfiles.com/blackphiles/PHILES/HP48_1/GROBS2.ZIP GROBS2.ZIP] | ||
* [http://www.hpcalc.org/details.php?id=4228 grobs49.zip] | * [http://www.hpcalc.org/details.php?id=4228 grobs49.zip] | ||
Revision as of 11:57, 22 September 2017
GROB is a (usually) bi-level raster graphics format associated with HP-48 and HP-49 series calculators.
There are two ways to encode a GROB image: "binary" and "ASCII". Sometimes, GROB images are also ASC-encoded.
Contents |
Format details
Binary format has an 18-byte header, followed by the pixel data.
Grayscale images
Although the format only really supports bi-level images, some images are intended to be interpreted as grayscale with 2 bits/pixel (or perhaps more). The physical image consists of the bit-planes stacked vertically. Unfortunately, there does not seem to be any way to detect whether this is the case.
Identification
A binary GROB file begins with "HPHP48" or "HPHP49", and has bytes 1E 2B at offset 8.
ASCII format apparently begins with "GROB ". An ASCII GROB might be embedded inside a script, or preceded by a "%%HP" header line, so it won't necessarily start at the beginning of the file.
Software
- Konvertor
- XnView
- grob.to.bitmap
- grob2eps.c
- My HP48 and HP49 software → hp48-mf-0.6.zip → hp48.dtx → grob2eps.c
