jimp-dev/jimp

Even sized kernel support

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#749 创建于 2019年6月7日

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 (0 评论) (0 反应) (0 负责人)JavaScript (13,218 star) (785 fork)batch import
enhancementhelp wanted

描述

Is your feature request related to a problem? Please describe. It would be useful to have even sized kernel support for convolution etc.

Describe the solution you'd like The implementation could follow Matlabs imfilter/conv2 algorithm. Imfilter(M, k) result is same as conv2(M, k, 'same').

Matlabs documentation states: "If you specify an even-sized kernel h, then the center of the kernel is floor((size(h) + 1)/2).

For example, the center of 4-element filter [0.25 0.75 -0.75 -0.25] is the second element, 0.75. This filter gives identical results as filtering with the 5-element filter [0 0.25 0.75 -0.75 -0.25]."

https://se.mathworks.com/help/images/ref/imfilter.html

贡献者指南

技术栈
javascriptnodejs
领域
backenddata
议题类型
feature
难度面向新贡献者的预计实现难度，1 表示很小改动，5 表示专家级工作。
3
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clear
前置要求
Convolution basicsJavaScript
新手友好度1-100 的估计分数，表示该议题对首次贡献者的友好程度。
45
研究方向
Examine the current convolution implementation in jimp (likely in a plugin like plugin rotate or plugin blur). The issue requests adding support for even sized kernels following Matlab's conv2 algorithm, where the center is floor((size(h)+1)/2). A good starting point is to review the existing convolution code and modify it to handle even sized kernels by aligning the center to floor((size+1)/2). Testing should include cases with 2x2 and 4x1 kernels to ensure output matches expected results.