Basic transformations like rotate, resize, crop and flip. The geometry syntax is used to specify sizes and areas.
image_trim(image, fuzz = 0)
image_chop(image, geometry)
image_rotate(image, degrees)
image_resize(image, geometry = NULL, filter = NULL)
image_scale(image, geometry = NULL)
image_sample(image, geometry = NULL)
image_crop(image, geometry = NULL, gravity = NULL, repage = TRUE)
image_extent(image, geometry, gravity = "center", color = "none")
image_flip(image)
image_flop(image)
image_deskew(image, threshold = 40)
image_deskew_angle(image, threshold = 40)
image_page(image, pagesize = NULL, density = NULL)
image_repage(image)
image_orient(image, orientation = NULL)
image_shear(image, geometry = "10x10", color = "none")
image_distort(image, distortion = "perspective", coordinates, bestfit = FALSE)magick image object returned by image_read() or image_graph()
relative color distance (value between 0 and 100) to be considered similar in the filling algorithm
a geometry string specifying area (for cropping) or size (for resizing).
value between 0 and 360 for how many degrees to rotate
string with filter type from: filter_types
string with gravity value from gravity_types.
resize the canvas to the cropped area
a valid color string such as
"navyblue" or "#000080". Use "none" for transparency.
straightens an image. A threshold of 40 works for most images.
geometry string with preferred size and location of an image canvas
geometry string with vertical and horizontal resolution in pixels of the image. Specifies an image density when decoding a Postscript or PDF.
string to set image orientation one of the orientation_types.
If NULL it applies auto-orientation which tries to infer the correct orientation
from the Exif data.
string to set image orientation one of the distort_types.
numeric vector (typically of length 12) with distortion coordinates
if set to TRUE the size of the output image can be different from input
For details see Magick++ STL documentation. Short descriptions:
image_trim removes edges that are the background color from the image.
image_chop removes vertical or horizontal subregion of image.
image_crop cuts out a subregion of original image
image_rotate rotates and increases size of canvas to fit rotated image.
image_deskew auto rotate to correct skewed images
image_resize resizes using custom filterType
image_scale and image_sample resize using simple ratio and pixel sampling algorithm.
image_flip and image_flop invert image vertically and horizontally
The most powerful resize function is image_resize which allows for setting
a custom resize filter. Output of image_scale is similar to image_resize(img, filter = "point").
For resize operations it holds that if no geometry is specified, all frames
are rescaled to match the top frame.
logo <- image_read("logo:")
logo <- image_scale(logo, "400")
image_trim(logo)
#> # A tibble: 1 × 7
#> format width height colorspace matte filesize density
#> <chr> <int> <int> <chr> <lgl> <int> <chr>
#> 1 GIF 287 296 sRGB FALSE 0 72x72
image_chop(logo, "100x20")
#> # A tibble: 1 × 7
#> format width height colorspace matte filesize density
#> <chr> <int> <int> <chr> <lgl> <int> <chr>
#> 1 GIF 300 280 sRGB FALSE 0 72x72
image_rotate(logo, 45)
#> # A tibble: 1 × 7
#> format width height colorspace matte filesize density
#> <chr> <int> <int> <chr> <lgl> <int> <chr>
#> 1 GIF 496 496 sRGB FALSE 0 72x72
# Small image
rose <- image_convert(image_read("rose:"), "png")
# Resize to 400 width or height:
image_resize(rose, "400x")
#> # A tibble: 1 × 7
#> format width height colorspace matte filesize density
#> <chr> <int> <int> <chr> <lgl> <int> <chr>
#> 1 PNG 400 263 sRGB FALSE 0 72x72
image_resize(rose, "x400")
#> # A tibble: 1 × 7
#> format width height colorspace matte filesize density
#> <chr> <int> <int> <chr> <lgl> <int> <chr>
#> 1 PNG 609 400 sRGB FALSE 0 72x72
# Resize keeping ratio
image_resize(rose, "400x400")
#> # A tibble: 1 × 7
#> format width height colorspace matte filesize density
#> <chr> <int> <int> <chr> <lgl> <int> <chr>
#> 1 PNG 400 263 sRGB FALSE 0 72x72
# Resize, force size losing ratio
image_resize(rose, "400x400!")
#> # A tibble: 1 × 7
#> format width height colorspace matte filesize density
#> <chr> <int> <int> <chr> <lgl> <int> <chr>
#> 1 PNG 400 400 sRGB FALSE 0 72x72
# Different filters
image_resize(rose, "400x", filter = "Triangle")
#> # A tibble: 1 × 7
#> format width height colorspace matte filesize density
#> <chr> <int> <int> <chr> <lgl> <int> <chr>
#> 1 PNG 400 263 sRGB FALSE 0 72x72
image_resize(rose, "400x", filter = "Point")
#> # A tibble: 1 × 7
#> format width height colorspace matte filesize density
#> <chr> <int> <int> <chr> <lgl> <int> <chr>
#> 1 PNG 400 263 sRGB FALSE 0 72x72
# simple pixel resize
image_scale(rose, "400x")
#> # A tibble: 1 × 7
#> format width height colorspace matte filesize density
#> <chr> <int> <int> <chr> <lgl> <int> <chr>
#> 1 PNG 400 263 sRGB FALSE 0 72x72
image_sample(rose, "400x")
#> # A tibble: 1 × 7
#> format width height colorspace matte filesize density
#> <chr> <int> <int> <chr> <lgl> <int> <chr>
#> 1 PNG 400 263 sRGB FALSE 0 72x72
image_crop(logo, "400x400+200+200")
#> # A tibble: 1 × 7
#> format width height colorspace matte filesize density
#> <chr> <int> <int> <chr> <lgl> <int> <chr>
#> 1 GIF 200 100 sRGB FALSE 0 72x72
image_extent(rose, '200x200', color = 'pink')
#> # A tibble: 1 × 7
#> format width height colorspace matte filesize density
#> <chr> <int> <int> <chr> <lgl> <int> <chr>
#> 1 PNG 200 200 sRGB FALSE 0 72x72
image_flip(logo)
#> # A tibble: 1 × 7
#> format width height colorspace matte filesize density
#> <chr> <int> <int> <chr> <lgl> <int> <chr>
#> 1 GIF 400 300 sRGB FALSE 0 72x72
image_flop(logo)
#> # A tibble: 1 × 7
#> format width height colorspace matte filesize density
#> <chr> <int> <int> <chr> <lgl> <int> <chr>
#> 1 GIF 400 300 sRGB FALSE 0 72x72
skewed <- image_rotate(logo, 5)
deskewed <- image_deskew(skewed)
attr(deskewed, 'angle')
#> [1] -4.80068
if(magick_config()$version > "6.8.6")
image_orient(logo)
#> # A tibble: 1 × 7
#> format width height colorspace matte filesize density
#> <chr> <int> <int> <chr> <lgl> <int> <chr>
#> 1 GIF 400 300 sRGB FALSE 0 72x72
image_shear(logo, "10x10")
#> # A tibble: 1 × 7
#> format width height colorspace matte filesize density
#> <chr> <int> <int> <chr> <lgl> <int> <chr>
#> 1 GIF 453 361 sRGB FALSE 0 72x72
building <- demo_image('building.jpg')
image_distort(building, 'perspective', c(7,40,4,30,4,124,4,123,85,122,100,123,85,2,100,30))
#> # A tibble: 1 × 7
#> format width height colorspace matte filesize density
#> <chr> <int> <int> <chr> <lgl> <int> <chr>
#> 1 JPEG 146 150 sRGB FALSE 0 72x72