crop

crop pixels by defining a selection box

$ pierogis crop ./input.jpg -x 20 --height 400 --aspect 1 --origin c

very chill.

The interface for cropping is based on defining a rectangular area to select out of the image.

--width and --height will correspond to percentages of input width if they are decimals (.5 meaning: spanning half of the input width). 1 does not mean 100% of the pixels, leave out height/width to do that!

You can provide -x and -y to define an offset from the origin at which the rectangle is pegged. x=0, y=0 corresponds to the bottom left of the image.

-x and -y will also correspond to percentages if they are decimals (.5 meaning: halfway offset from origin to end of the image in that axis).

You can provide a direction that will define the origin and the direction of the selection

origins

• sw bottom left (default) -> top right

• se bottom right -> top left

• nw top left -> bottom right

• ne top right -> bottom left

• n top center -> bottom center

• s bottom center -> top center

• e center right -> center left

• w center left -> center right

• c center center -> outwards

--aspect will crop the image to the given aspect ratio. It achieves this in different ways depending on the other options provided.

• If neither --width nor --height are provided, it will preserve one dimension and reduce another so as to not increase in size. Same treatment as resize.

• If both --width and --height are provided, the --aspect is ignored.

• If one of --width or --height are provided, the --aspect is applied to the missing dimension.

Pixel coordinates within the rectangle but without the input image will be ignored.

arg	description	default	valid
--origin	origin location and opposing direction to crop toward	sw	see origins
-x	x origin offset; decimal for relative to input width	0	float, int
-y	x origin offset; decimal for relative to input height	0	float, int
--width	width to capture; decimal for relative to input width	None	float, int
--height	width to capture; decimal for relative to input height	None	float, int
--aspect	aspect ratio; ignored if height and width present	None	float

The following table explains the x,y coordinates (the last 4 columns) of the cropped output’s bottom left and top right corners for each set of inputs.

0,0 corresponds to the left,bottom of an image and a larger x,y coordinate indicates toward the right,top of the image. If you are reading this you are a champion.

Crop Examples

x	y	width	height	origin	aspect	bottom left x	bottom left y	top right x	top right y
0	0	None	None	None	None	0	0	500	500
0	0	100	100	None	None	0	0	100	100
0	0	100	100	sw	None	0	0	100	100
0	0	100	100	se	None	400	0	500	100
0	0	100	100	nw	None	0	400	100	500
0	0	100	100	ne	None	400	400	500	500
0	0	100	100	c	None	200	200	300	300
0	0	100	100	n	None	200	400	300	500
0	0	100	100	e	None	400	200	500	300
0	0	100	100	s	None	200	0	300	100
0	0	100	100	w	None	0	200	100	300
0	0	100	None	sw	None	0	0	100	500
0	0	None	100	sw	None	0	0	500	100
100	0	100	None	sw	None	100	0	200	500
0	100	100	None	sw	None	0	100	100	500
100	0	100	None	nw	None	100	0	200	500
-100	0	100	None	ne	None	300	0	400	500
-0.2	0.2	100	None	se	None	300	100	400	500
-100	0	100	None	c	None	100	0	200	500
0.2	0	100	None	c	None	300	0	400	500
0	0.2	100	None	c	None	200	100	300	500
0	0	None	None	sw	2	0	0	500	250
0	0	None	None	ne	0.5	250	0	500	500
0	0	None	200	sw	2	0	0	400	200
0	100	None	200	c	0.5	200	250	300	450
0	0	100	None	n	2	200	450	300	500
0	0	100	100	e	2	400	200	500	300

See: CropFilling, Crop