exceljs/exceljs

[Bug] Insert Image to Excel returns wrong size

Open

#1,036 opened on Nov 25, 2019

View on GitHub
 (7 comments) (3 reactions) (0 assignees)JavaScript (11,838 stars) (1,534 forks)batch import
help wanted

Description

I have an image that has 191x47 pixels. arubaito

    worksheet.addImage(imageID, {
      tl: { col: column, row: row },
      ext: { width: size.width, height: size.height }, // width: 191, height: 47
    });

But when I open excel file, the height was automatically scaled 160%, and 157% with width.

So how can I insert the original size of an image to excel?

Contributor guide

Tech stack
javascriptnodejs
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.
half day
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
Basic JavaScriptUnderstanding of ExcelJS addImage method
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40
Research direction
Investigate how `worksheet.addImage` handles the `ext` parameter and converts pixels to EMUs. Look at the source code, particularly the `drawing.js` or `image.js` files, to understand the scaling logic. Check if there are any unit conversion issues or fixed DPI assumptions. Review comments in the issue for any hints about the correct usage or workarounds. Test with a simple image to reproduce the scaling behavior and compare with expected output.
[Bug] Insert Image to Excel returns wrong size · exceljs/exceljs#1036 | Good First Issue