{"slug":"understanding-sharpening","title":"你真的理解锐化了吗？","author":"Thomas看看世界","date":"2016-09-18","wechat":"https://mp.weixin.qq.com/s?__biz=MzI4NDA5MzE5NQ==&mid=2247484378&idx=1&sn=c68b3db57013acbb3aa1ae403363b34d&chksm=eb81fdbedcf674a891f8b28e4cf3aa814efba2d582ae0e3802af00e07aef3a398adc0d963e0e&scene=21#wechat_redirect","blocks":[{"t":"p","x":"锐化是摄影后期中人人都在用，但又无比复杂的一门学问。Lab锐化、高反差保留、分步锐化、边缘蒙板...各种锐化方法简直烧脑，以至于有一本300多页的书籍《数码影像锐化深度剖析》专门就讲锐化这一件事儿。","b":false,"xe":"Sharpening is a discipline everyone uses in photo post-processing, yet it is incredibly complex. Lab sharpening, high pass, multi-step sharpening, edge masking... the various methods are mind-boggling — there's even a 300-plus-page book, 'Real World Image Sharpening', devoted to sharpening alone."},{"t":"p","x":"托马斯今天却会化繁为简，从锐化的基本原理说起，告诉你如何使用最简单又足够强大的ACR/Lightroom细节面板，对图像进行锐化。","b":false,"xe":"Today, Thomas simplifies it all: starting from the basic principle of sharpening, I'll show you how to use the simplest yet sufficiently powerful Detail panel in ACR/Lightroom to sharpen your images."},{"t":"p","x":"知识点：锐化的原理，数量、半径、细节、蒙板四大要素","b":false,"xe":"Topics: the principle of sharpening; the four elements — Amount, Radius, Detail, Masking"},{"t":"p","x":"阅读本文需要约8分钟","b":false,"xe":"Reading time: about 8 minutes"},{"t":"h","x":"1","xe":"1"},{"t":"h","x":"锐化的原理","xe":"The principle of sharpening"},{"t":"p","x":"托马斯在网上看过不少“锐化秘籍”，直接给出类似“数量100半径1.2”的“黄金参数”。但是锐化的多少，是取决于图像的大小、内容、输出媒介等等很多因素，绝不会有最佳参数一说。只有理解锐化的原理和要点，用我们的眼睛来判断每幅图片，才是最好的锐化方案。","b":false,"xe":"Thomas has seen many 'sharpening secrets' online that directly hand out 'golden parameters' like 'Amount 100, Radius 1.2'. But how much sharpening to apply depends on the image's size, content, output medium and many other factors — there is no such thing as a best parameter. Only by understanding the principles and judging each image with our own eyes can we sharpen best."},{"t":"p","x":"锐化的原理其实很简单，就是通过增强物体边缘的对比度和区隔度，来让边缘显得更清晰锐利。比如下面的这个边缘，一边是75%灰度的深灰色物体，一边是25%灰度的浅灰色物体。（此处灰度值为大概值，只需要注意相对大小即可）","b":false,"xe":"The principle of sharpening is actually simple: by enhancing the contrast and separation along object edges, edges appear clearer and sharper. For example, in the edge below, one side is a dark gray object at 75% gray and the other a light gray object at 25%. (The gray values are approximate; only the relative sizes matter.)"},{"t":"img","f":"img-02","w":640,"h":443},{"t":"p","x":"我用PS对上图加锐。可以看到图中的边缘多出了另外4条线条，原本只有75%灰和25%灰的图像变成了6种颜色，从左到右分别为：","b":false,"xe":"I sharpened the image above in PS. You can see 4 extra lines appear along the edge — the image that had only 75% and 25% gray now has 6 tones, from left to right:"},{"t":"p","x":"（原本75%灰的）物体－（60%灰的）隔离带－（90%灰的）边缘线条－（10%灰的）边缘线条－（40%灰的）隔离带－（原来25%灰的）物体","b":false,"xe":"(originally 75% gray) object — (60% gray) separation band — (90% gray) edge line — (10% gray) edge line — (40% gray) separation band — (originally 25% gray) object"},{"t":"img","f":"img-03","w":640,"h":439},{"t":"p","x":"首先看看物体最边缘的部分，出现了接近一黑一白的两条线条，这样原来物体边缘75% vs 25%的亮度对比，一下子提高到了90% vs 10%，边缘反差对比更大，看起来更加锐利。","b":false,"xe":"First look at the very edge of the object: two nearly black and white lines appear, so the original 75% vs 25% brightness contrast jumps to 90% vs 10% — greater edge contrast, looking sharper."},{"t":"p","x":"其次看看（90%灰的）物体边缘和（75%灰的）物体之间，为什么又多出来一条比这两个地方亮度都更浅的（60%灰）区域？这是因为锐化除了让边缘对比更强之外，还把物体边缘从物体本身分离了出来。这层新出来的隔离带，就是起到让边缘和物体本身区别更明显的“分离”作用。","b":false,"xe":"Next, why is there an extra (60% gray) band — lighter than both sides — between the (90% gray) edge line and the (75% gray) object? Because sharpening not only strengthens edge contrast, it also separates the edge from the object itself. This new separation band makes the edge more distinct from the object's interior."},{"t":"p","x":"所以锐化的原理，一是让边缘反差更大，二是让边缘更加明显（与物体内部分隔开来）。","b":false,"xe":"So the principle of sharpening is twofold: first, greater edge contrast; second, more distinct edges (separated from the object's interior)."},{"t":"h","x":"2","xe":"2"},{"t":"h","x":"ACR/LR 锐化工具","xe":"The ACR/LR sharpening tool"},{"t":"p","x":"光理解了原理还不够，怎么用才是关键。","b":false,"xe":"Understanding the principle isn't enough — how to use it is the key."},{"t":"p","x":"Adobe Camera Raw中，锐化工具在第三个面板 － 细节面板。","b":false,"xe":"In Adobe Camera Raw, the sharpening tool lives in the third panel — the Detail panel."},{"t":"img","f":"img-04","w":611,"h":640},{"t":"p","x":"在Lightroom（LR）中，细节菜单在分离色调菜单的下面。","b":false,"xe":"In Lightroom (LR), the Detail section sits below Split Toning."},{"t":"img","f":"img-05","w":640,"h":577},{"t":"p","x":"无论哪种软件，细节面板中的锐化工具，都有四个滑块：数量、半径、细节和蒙板。他们恰好对应了锐化中存在的三大问题。","b":false,"xe":"In either application, the sharpening tool in the Detail panel has four sliders: Amount, Radius, Detail and Masking. They correspond exactly to the three major problems in sharpening."},{"t":"img","f":"img-06","w":640,"h":437},{"t":"p","x":"以上面这张锐化过度的照片为例，三个问题分别是：","b":false,"xe":"Take the over-sharpened photo above as an example — the three problems are:"},{"t":"p","x":"1）叶片边缘锐化强度过大，显得很假。而锐化强度，是由“数量”滑块决定的。","b":false,"xe":"1) The leaf edges are sharpened too strongly and look fake. Sharpening strength is decided by the 'Amount' slider."},{"t":"p","x":"2）叶片边缘出现了明显的白边和黑边，这是因为锐化作用的区域过大，本应很细微的边缘对比，一下子成了一大条白色和黑色色块。锐化区域，是由“半径”滑块控制。","b":false,"xe":"2) Obvious white and black fringes appear along the leaf edges — the sharpened region is too wide, turning what should be a subtle edge contrast into big white and black blobs. The sharpening region is controlled by the 'Radius' slider."},{"t":"p","x":"3）水面内部本来不是边缘的区域也被锐化了，一下子多了很多噪点。而识别哪些是边缘，哪些不是边缘，由“细节”和“蒙板”滑块控制。","b":false,"xe":"3) Areas inside the water that aren't edges got sharpened too, suddenly adding lots of noise. Deciding what is and isn't an edge is controlled by the 'Detail' and 'Masking' sliders."},{"t":"h","x":"2.1","xe":"2.1"},{"t":"h","x":"锐化数量","xe":"Sharpening Amount"},{"t":"p","x":"锐化数量决定了锐化的强度，也就是边缘的对比度，以及边缘和物体的隔离程度。下面是ACR默认的25数量时，边缘的锐化情况。","b":false,"xe":"Amount decides the sharpening strength — i.e., the edge contrast and the degree of separation between edge and object. Below is the edge at ACR's default Amount of 25."},{"t":"img","f":"img-07","w":640,"h":443},{"t":"p","x":"一旦把锐化数量提高到150，不仅边缘深浅两种颜色的反差更大，而且还出现了多条“隔离带”，让边缘更明显了。","b":false,"xe":"Once Amount is raised to 150, not only is the contrast between the two edge tones greater, but multiple 'separation bands' appear, making the edge even more prominent."},{"t":"img","f":"img-08","w":640,"h":530},{"t":"p","x":"在具体的照片中，我们需要根据物体的特点决定锐化数量，比如人物照片可能20、30就够了，而建筑雕塑这类超过100也不觉得过。怎么观察呢，第一步，把照片放大到100%甚至更大，这样才能清楚的看到锐化效果。","b":false,"xe":"On real photos, we decide Amount based on the subject: portraits may only need 20-30, while architecture and sculptures can exceed 100 without looking overdone. How to judge? Step one: zoom the photo to 100% or more, so you can clearly see the sharpening effect."},{"t":"img","f":"img-09","w":640,"h":356},{"t":"p","x":"第二步，拖动数量滑块，直到物体的边缘和细节凸显出来。（拖动数量滑块的时候，同时按住Alt键，可以把照片由彩色变成黑白，更加方便观察）","b":false,"xe":"Step two: drag the Amount slider until the object's edges and details stand out. (While dragging, hold Alt to turn the photo black-and-white for easier observation.)"},{"t":"img","f":"img-10","w":640,"h":400},{"t":"h","x":"2.2","xe":"2.2"},{"t":"h","x":"锐化半径","xe":"Sharpening Radius"},{"t":"p","x":"锐化半径决定了锐化作用的区域，半径越大，边缘会有更多区域成为反差隔离带。比如下面这张照片，半径设为默认的1.0时，边缘被锐化的区域只有3个像素。","b":false,"xe":"Radius decides the region the sharpening acts on — the larger the radius, the more area around an edge becomes a contrast band. In the photo below, with the default Radius of 1.0, only 3 pixels along the edge are sharpened."},{"t":"img","f":"img-11","w":640,"h":497},{"t":"p","x":"当半径增加到3.0时，边缘8-9个像素到区域都产生了锐化效果。","b":false,"xe":"When Radius increases to 3.0, the sharpened region along the edge grows to 8-9 pixels."},{"t":"img","f":"img-12","w":640,"h":423},{"t":"p","x":"半径太大，物体边缘会有黑边白边的出现，看起来有点恐怖。","b":false,"xe":"Too large a radius creates black and white fringes around object edges — looking rather scary."},{"t":"img","f":"img-13","w":640,"h":495},{"t":"p","x":"记住在细节面板中，键盘上的Alt键是一个非常有用的按键。在调整半径时，按住Alt键，可以看到物体边缘锐化的作用效果。","b":false,"xe":"Remember: in the Detail panel, the Alt key is extremely useful. While adjusting Radius, hold Alt to see exactly where sharpening acts along the edges."},{"t":"img","f":"img-14","w":640,"h":586},{"t":"p","x":"按住Alt键，半径过大时，会有比较明显的黑白线条出现。一般照片，锐化半径都保持在默认的1或者更低，极少有超过1.5的情况。","b":false,"xe":"Holding Alt, an oversized radius shows obvious black and white lines. For most photos, keep Radius at the default 1 or lower — it rarely exceeds 1.5."},{"t":"img","f":"img-15","w":640,"h":573},{"t":"h","x":"2.3","xe":"2.3"},{"t":"h","x":"锐化细节","xe":"Sharpening Detail"},{"t":"p","x":"就像“细节”字面本身提示的那样，这个滑块决定了多大的边缘才会被锐化。当细节值很小时，表示我们不需要多少细节，只有很大很明显的边缘才会被锐化。","b":false,"xe":"As the word 'Detail' suggests, this slider decides how big an edge must be to get sharpened. A small Detail value means we want little detail — only large, obvious edges get sharpened."},{"t":"p","x":"同样调整细节的同时按住Alt键，会显示出一个中灰色图像，图像中50%灰的区域是不被锐化影响的细节，更深更浅的部分则是会被锐化的细节。比如这张建筑照片，按住Alt键同时细节滑到0，只有轮廓清晰的建筑边缘显示了出来。","b":false,"xe":"Likewise, hold Alt while adjusting Detail: a mid-gray image appears, where 50% gray areas are detail unaffected by sharpening, while darker and lighter parts are detail that will be sharpened. In this architecture photo, holding Alt with Detail at 0, only the crisply outlined building edges show."},{"t":"img","f":"img-16","w":640,"h":499},{"t":"p","x":"如果我把细节值提高到26，一些更小的边缘也会被锐化。比如箭头所指的建筑墙体的花纹，在细节为0时被直接忽略了，在细节26时则会被锐化。","b":false,"xe":"If I raise Detail to 26, some smaller edges get sharpened too. For example, the patterns on the building's wall indicated by the arrow were ignored at Detail 0, but get sharpened at 26."},{"t":"img","f":"img-17","w":640,"h":504},{"t":"p","x":"如果我进一步把细节提高到100，图像中大大小小的各种边缘都会被锐化，甚至纯色天空中的噪点也会被锐化，这显然不是我们想要的。一般来说，默认的25是一个对大部分照片适用的值。","b":false,"xe":"If I push Detail further to 100, edges big and small all get sharpened — even noise in the pure-color sky gets sharpened, which is obviously not what we want. In general, the default 25 suits most photos."},{"t":"img","f":"img-18","w":640,"h":511},{"t":"h","x":"2.4","xe":"2.4"},{"t":"h","x":"锐化蒙板","xe":"Sharpening Masking"},{"t":"p","x":"细节是一个加法，细节值越大，越细微的边缘也会被锐化。而蒙板则是一个减法，它会识别出照片中类似天空、水面、皮肤等大片纯色区域，让锐化不作用于这些区域。蒙板是锐化工具中，重要程度最高的一个滑块，它让我们实现了局部锐化。","b":false,"xe":"Detail is additive — the larger its value, the finer the edges that get sharpened. Masking is subtractive: it identifies large solid-color areas like sky, water and skin, and keeps sharpening away from them. Masking is the most important slider in the sharpening tool — it gives us local sharpening."},{"t":"p","x":"蒙板为0的时候，大片天空也被锐化，本来应该纯蓝一片的天空却出现了许多颗粒。","b":false,"xe":"With Masking at 0, the whole sky gets sharpened, and what should be pure blue sky shows many grainy artifacts."},{"t":"img","f":"img-19","w":640,"h":469},{"t":"p","x":"同样按住Alt键时移动蒙板滑块，图像中会显示出蒙板的作用情况，黑色表示完全不会被锐化，白色表示该部分会被锐化。蒙板提高到25，天空中仍然有大量白色线条，那些地方会被锐化，不好！","b":false,"xe":"Likewise, hold Alt while moving the Masking slider: black means completely protected from sharpening, white means sharpened. At Masking 25, the sky still shows many white lines — those areas would be sharpened. Not good!"},{"t":"img","f":"img-20","w":640,"h":400},{"t":"p","x":"蒙板直接升到100，天空中一片黑色，说明天空完全不会被锐化。不过这个时候建筑内部也是大片黑色，该被锐化的墙体细节没有锐化，蒙板拉的过了！","b":false,"xe":"Push Masking straight to 100: the sky turns fully black — it won't be sharpened at all. But now the building interior is also largely black — wall details that should be sharpened aren't. Masking has gone too far!"},{"t":"img","f":"img-21","w":640,"h":400},{"t":"p","x":"对这张图而言，蒙板值在60左右时比较平衡。天空几乎一片黑色，不会被锐化。同时建筑中的纹理仍然是白色蒙板，会被锐化。","b":false,"xe":"For this image, a Masking value around 60 is balanced. The sky is almost fully black (unsharpened), while the building textures remain white (sharpened)."},{"t":"img","f":"img-22","w":640,"h":400},{"t":"p","x":"再来看看蒙板为0和蒙板为60时，天空的“颗粒噪点”情况。左边是蒙板为0，右边蒙板拉到了60，保护纯色区域的效果立竿见影。","b":false,"xe":"Now compare the sky's 'grain noise' at Masking 0 vs 60. Left is 0, right is 60 — the protection of solid-color areas is instantly obvious."},{"t":"img","f":"img-23","w":640,"h":433},{"t":"h","x":"总结","xe":"Summary"},{"t":"quote","x":"1. 锐化的原理，一是让边缘反差更大，二是让边缘更加明显（与物体内部分隔开来）。 2. Lightroom／ACR中的细节面板－锐化工具一共有四个滑块：控制锐化强度的“数量”，控制边缘被锐化影响区域的“半径”，控制多大的边缘才被锐化的细节，以及消除锐化对纯色区域作用的“蒙板”。 3. 锐化没有黄金参数，需要用眼睛观察来确保3大问题不要发生：用“数量”滑块确保锐化强度不过，用“半径”滑块保证物体边缘没有亮边黑边，用“细节”和“蒙板”让照片需要的边缘被锐化，不需要锐化的区域被保护。","xe":"1. The principle of sharpening: first, greater edge contrast; second, more distinct edges (separated from the object's interior). 2. The Detail panel in Lightroom/ACR has four sharpening sliders: 'Amount' controls strength; 'Radius' controls the region affected along edges; 'Detail' controls how big an edge must be to get sharpened; and 'Masking' removes sharpening from solid-color areas. 3. There are no golden parameters — judge with your eyes to avoid the 3 problems: use 'Amount' to avoid excessive strength, 'Radius' to avoid bright/dark fringes, and 'Detail' + 'Masking' so edges that need it get sharpened while areas that don't are protected."},{"t":"p","x":"我是@Thomas看看世界，每个周日晚上，分享一篇原创摄影干货。","b":false,"xe":"I'm @Thomas Chu Photo — every Sunday evening I share an original piece of photography know-how."}],"titleEn":"Do You Really Understand Sharpening?"}