test_image {fastpng} | R Documentation |
Test images in various R formats
Description
A nested named list of test images (300 x 200 pixels).
Usage
test_image
Format
An object of class list
of length 9.
Details
Possible image color spaces within each image type
- $gray
Gray pixels representing intensity only
- $gray_alpha
Gray pixels with an alpha channel
- $rgb
RGB color image
- $rgba
RGB color image with alpha channel
A description of the image data within each image type
- test_image$array
-
Arrays of numeric values in the range [0, 1]
- $gray
A 2D matrix
- $gray_alpha
A 3D array with 2 planes i.e.
dim(x)[3] == 2
- $rgb
A 3D array with 3 planes i.e.
dim(x)[3] == 2
- $rgba
A 3D array with 4 planes i.e.
dim(x)[3] == 2
- test_image$array_16bit
-
Same as
test_image$array
data except values contain 16 bits of signficant color information. - test_image$array_int
-
Arrays of integer values in the range [0, 255]
- $gray
A 2D matrix
- $gray_alpha
A 3D array with 2 planes i.e.
dim(x)[3] == 2
- $rgb
A 3D array with 3 planes i.e.
dim(x)[3] == 2
- $rgba
A 3D array with 4 planes i.e.
dim(x)[3] == 2
- test_image$array_int_16bit
-
Same as
test_image$array_int
data except values are in the range [0, 65535] - test_image$raster
-
- $rgb
Raster image of color values given as hex codes
#RRGGBB
- $rgba
Raster image of color values given as hex codes
#RRGGBBAA
- $named
Raster image of color values given as R color names e.g. 'red', 'blue'
- test_image$nativeraster
-
Integer matrix of integer values. Each 32-bit numeric value holds a packed RGBA pixel
- $rgba
- test_image$indexed
-
- $integer_index
An integer matrix. Each value is an index into a separately specified color-lookup table
- $numeric_index
A numeric matrix. Each value is an index into a separately specified color-lookup table
- $palette
An example color palette to use with indexed images. 256 colors.
- test_image$raw
-
Sequences of raw bytes with attributes specifying 'width', 'height', 'depth' (i.e. number of colors) and 'bits' (number of bits for each color)
- $gray
Sequence of gray pixels i.e. GGGG
- $gray_alpha
Sequence of GA pixels i.e. GAGAGA...
- $rgb
Sequence of RGB pixels i.e. RGBRGBRGB...
- $rgba
Sequence of RGB pixels i.e. RGBARGBARGBA...
- test_image$raw_16_bit
-
The same as
test_image$raw
except each color takes 2 raw bytes.