描述

Expected Behavior

Colour of BMP image shouldn't change.

Current Behavior

The reds turn to green, and the blues turn to red.

Failure Information (for bugs)

Seems related to the endian of the BMP perhaps?

Steps to Reproduce

I have a replication of this bug in a code sandbox. After reading the bmp and turning it into a base64 it changes the colours. I've included the image in the sandbox.

https://codesandbox.io/s/angry-gauss-nnd63?fontsize=14&hidenavigation=1&theme=dark

Screenshots

Context

We have a part of our application where users can upload their own images and apply filters to them. Some user images may be in BMP format.

Jimp Version: codesandbox's
Operating System: Windows 10
Node version: codesandbox's

Failure Logs

n/a

贡献者指南

技术栈: javascriptnodejs
领域: backend
议题类型: bug
难度: 3
预计时间: 1-3 hours
活动状态: stale
清晰度: mostly clear
前置要求: BMP file formatendiannessNode.js buffer handling
新手友好度: 60
研究方向: Investigate the BMP decoder in the Jimp source code, likely in `src/image/bmp.js`. The issue suggests an endianness problem when reading the BMP header and pixel data. Use the provided sandbox (https://codesandbox.io/s/angry gauss nnd63) to test changes. Compare the byte order for red, green, blue channels and verify against BMP specification. Check if the BMP version (e.g., BITMAPINFOHEADER) affects the color order.