lovell/sharp

Enhancement: add support to extend feature for width and height

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#1,072 opened on Dec 19, 2017

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 (9 comments) (0 reactions) (0 assignees)JavaScript (31,994 stars) (1,389 forks)batch import
enhancementhelp wanted

Description

Hello,

is there a way to pad an image if it's smaller than required dimensions?

For example:

desired dimensions actual dimensions expected result
1000x1000 200x200 1000x1000 image with 200x200 centered inside
300x300 350x350 downscaled to 300x300

Original original

Desired output large

Contributor guide

Tech stack
javascriptnodejs
Domain
backendfull stack
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
Understanding of sharp's image processing pipelineFamiliarity with libvips extend operationBasic knowledge of Node.js and JavaScript
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
30
Research direction
This feature request asks for adding support to extend an image to fit desired dimensions, padding if necessary. libvips already supports extend with gravity options. The implementation should modify sharp's resize logic to accept an extend/gravity parameter. Look at libvips documentation for `vips gravity` and `vips extend`. The issue's comments contain discussions about implementation approaches. To proceed, review the existing resize code in `src/pipeline.cc` and `lib/resize.js`. Consider adding a `position` or `gravity` option to the `.resize()` method.