| Type: | Package |
| Title: | Read and Write QOI Images |
| Date: | 2024-04-17 |
| Version: | 0.1.0 |
| Author: | Johannes Friedrich [aut, trl, cre], Dominic Szablewski [cph] (C library 'qoi') |
| Maintainer: | Johannes Friedrich <Johannes.Friedrich@posteo.de> |
| URL: | https://github.com/JohannesFriedrich/qoi4R |
| BugReports: | https://github.com/JohannesFriedrich/qoi4R/issues |
| Description: | The new QOI file format offers a very simple but efficient image compression algorithm. This package provides an easy and simple way to read, write and display bitmap images stored in the QOI (Quite Ok Image) format. It can read and write both files and in-memory raw vectors. |
| License: | MIT + file LICENSE |
| Encoding: | UTF-8 |
| NeedsCompilation: | yes |
| RoxygenNote: | 7.3.1 |
| Depends: | R (≥ 2.10) |
| LazyData: | true |
| Suggests: | testthat (≥ 3.0.0) |
| Config/testthat/edition: | 3 |
| Packaged: | 2024-04-17 17:25:47 UTC; johannes |
| Repository: | CRAN |
| Date/Publication: | 2024-04-17 17:40:12 UTC |
RGBA values for the Rlogo (https://www.r-project.org/logo/)
Description
RGBA values for the Rlogo (https://www.r-project.org/logo/)
Format
[matrix] with 561 x 724 x 4 elements
Author(s)
Johannes Friedrich
Read an QOI image into a RGB(A) raster array
Description
Read an QOI image into a RGB(A) raster array
Usage
readQOI(qoi_image_path)
Arguments
qoi_image_path |
character (required): Path to a stored qoi-image |
Value
A matrix with integer (0-255) RGB(A) values with dimensions height x width x channels. Until now 3 (RGB) and 4 (RGBA) channels are integrated in the specification. If the decoding went wrong the returned value is NULL.
Author(s)
Johannes Friedrich
Examples
## (1) Read RGBA values from file
path <- system.file("extdata", "Rlogo.qoi", package="qoi")
rlogo_qoi <- readQOI(path)
dim(rlogo_qoi)
## (2) plot them
plot.new()
Write an QOI image from an RGB(A) raster array or matrix
Description
Write an QOI image from an RGB(A) raster array or matrix
Usage
writeQOI(image, target = raw())
Arguments
image |
matrix (required): Image represented by a integer matrix or array with values in the range of 0 to 255. |
target |
character or connections or raw: Either name of the file to write, a binary connection or a raw vector (raw() - the default - is good enough) indicating that the output should be a raw vector. |
Value
The result is either stored in a file (if target is a file name), in a raw vector (if target is a raw vector) or sent to a binary connection.
Author(s)
Johannes Friedrich
Examples
## (1) Write to raw() -> see bytes
bin <- writeQOI(Rlogo_RGBA)
rawToChar(head(bin)) ## qoif
## Not run:
## (2) Write to a *.qoi file
writeQOI(Rlogo_RGBA, "Rlogo_RGBA.qoi")
## End(Not run)