Resizes the image to a specified width or height (in pixels) while keeping proportions and delivers the resulting image via CDN.

width | w

height | h

Examples

When resizing with width or height operation, Filerobot either reduces or increases the dimensions of the image to keep proportions. To prevent the image from getting resized to a bigger size than the original, use the org_if_sml operation.

org_if_sml=1

Examples

Allows to crop an image by providing the cropping area. It is useful when you want to crop a specific part of the image. To set the coordinates of the crop rectangle, use the tl_px and br_px operations.

tl_px=X1,Y1

br_px=X2,Y2

Examples

Original image: /docs/kids.jpg

Combining positionable crop with resize modes

Positionable crop can be combined with all available resize functions - width/height, crop, fit, bound or cover. This operation is performed after the positionable crop.

Examples

Finds the most prominent face in the image and crops it to specified dimension provided with the width and height parameters. If you however provide only one dimension, the other dimension will be chosen automatically to keep the aspect ratio of the face.

func=face

Examples

Face margin

Sets margins around the face. You can set equal margins with face_margin=X or separate horizontal and vertical margins (face_margin=W,H).

face_margin=X|W,H

Examples

Resizing operations enable the dynamic generation of image transformations to meet various web delivery use cases. Operations focus on the image size while allow to modify the image itself.

Available operations

Resize functions

When you specify both width and height, original image proportions can be either ignored or maintained. Also, you may choose to add padding to the image to fill the blank space.

Filerobot supports the following resize function (operation func).

Crop

Fit

Cropfit

Bound

Cover

Sets target aspect ratio or aspect ratio range when cropping. Aspect ratios can be set as decimal values (1.778) or ratios (16:9).

aspect_ratio=AR | ar=AR

aspect_ratio=AR1,AR2 | ar=AR1,AR2

Crop and resize

If you provide only one dimension parameter (width or height) and aspect_ratio, the other dimension will be calcualted. If you include both width and height in the URL, aspect_ratio is ignored.

Examples

Crop without resize

If you provide only aspect_ratio and no dimensions (width or height), the image will be cropped without resizing.

Examples

Aspect ratio range

You can spcify a range of aspect ratio, for example aspect_ratio=4:3,16:9. Images which fall within this range, will not be cropped. Useful to avoid very wide ot very tall images by cropping them to the closest aspect ratio.

Examples

Crops out the topmost part of an image if it contains a face.

To control the margin when cropping the face out, you can use the face_margin=Y operation where Y is a percentage of the face height. Its default value is 20. You can also use negative numbers if you would like to keep part of the face.

func=facehide

Examples

Resizes to a given width and height box and keeps proportions. Similar to Fit but without adding padding. Delivers the resulting image via CDN.

func=bound

Examples

Allows to crop an image by defining the coordinates of the crop focal point. It is useful when you want to crop images where the coordinates of the point of interest are already known.

To set the coordinates of the focal point, use the gravity=X,Y operation where X and Y are the coordinates of the focal point (in pixels). Alternatively, you can set the coordinates as a percentage of the original image - gravity=Xp,Yp or gravity=xc,yc, where X,Y=0..100 and x,y=0..1.

gravity=X,Y

gravity=Xp,Yp|xc,yc

Examples

Original image: /docs/castle.jpg?w=1000

Performs either or operation depending on the origin image and the desired transformation dimensions.

If the desired image is smaller than the original, the result is cropped to achieve the desired dimensions.

func=cropfit

Examples

Using cropfit with trim

If you include the operation in the URL, the image will be trimmed first (if possible) and then either cropped or fitted to the desired size.

Examples

Chooses the most important image features and objects and sets the focal point on them when cropping.

gravity=smart

gravity=auto

gravity=face

Smart gravity

Sets the crop focal point on the people in the image or on the most prominent featues if no faces are detected. Useful for creating thumbnails from images with different aspect ratios.

Examples

Automatic gravity (legacy)

If you prefer to use the legacy automatic crop, just set gravity operation to auto.

Examples

Face gravity

When using gravity=face, all images with one dominant face are focused on this face upon cropping. If there are many or no faces in the image, gravity falls back to auto.

Examples

Resizes an image while bounding the smaller dimension to the desired width or height while keeping proportions. Delivers the resulting image via CDN.

func=boundmin

Examples

Resizes the image to a specified width and height without keeping original proportions and delivers the resulting image via CDN.

func=cover

Examples

Crops the image to specified dimensions (width and height) while keeping proportions and delivers the resulting image via CDN.

func=crop

Examples

Gravity

Specifies which part of the image you wish to keep while cropping. If you omit the gravity option, central cropping is performed.

gravity=X

Available gravity values

Examples

Rotates the image by a specified angle, counterclockwise. You can use bg_color=X to set the background fill color if the rotation angle is not divisible by 90.

r=X

Examples

Mirrors the image horizontally and/or vertically.

flip=h | flip=v | flip=hv

Examples

Resizes the image to fit into a specified width and height box, adds padding (image or solid color) to keep proportions, and delivers the resulting image via CDN.

func=fit

The padding can be customised using the following additional operations:

Gravity

Examples

Rounds the corners of images with a radius of X pixels. If you wish to fill the cut corners with a specific colour, you can use the bg_color parameter.

radius=X

Examples

Removes any single-color padding around the image if present.

The parameter does not specify the amount of border or frame to trim but rather how aggressive the trim algorithm should be. A bigger value of the parameter (e.g. 25) will trim rather more than not enough. Typical values are between 0 and 10.

This allows you to use the same parameter values for all your images.

trim=X

Examples

Allows you to deliver the right image dimensions according to a defined device pixel ratio. This operation can help with conversion between device-independent pixels and CSS (reference) pixels. Useful in responsive image solutions using the srcset html attribute. Allows positive values limited to 5.

dpr=X

Examples