jimp-dev/jimp

Setting lower quality increases the file size

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#1,018 opened on Jun 2, 2021

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bugfile size issuehelp wanted

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Description

Expected Behavior

Decrease the file size with decrement in image quality.

Current Behavior

Increase the file size with decrement in image quality.

Code

jimp.read("./forest-patrol.jpg", (err, lenna) => {
  if (err) throw err;
  lenna
    .quality(60) // set JPEG quality
    .write("./forest-patrol-jimp-mini.jpg"); // save
});

bug-report Here, we can see that original image forest-patrol.jpg is smaller than the processed image forest-patrol-jimp.jpg

Contributor guide

Research direction
Investigate the JPEG quality encoding implementation in Jimp to understand why lower quality settings can result in larger file sizes. Check the library's handling of quantization tables and chroma subsampling.
Tech stack
javascript
Domain
backend
Issue type
Bug
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.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Node.jsJimp
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70