图像检索技术在实用领域还是比较少的，特别是比较难的技术，这里收集了几个简单的只是黑白图像检索引擎。英语，不翻译了。

If you share my passion for black and white photography, you will find this toolset especially useful and bookmark-worthy: the top 5 image search engines to find black and white photos.

1. Multicolr

Multicolr is a Flickr-based image search engine that allows you to search by color (I’ve already mentioned it previously). To see only black and white photography, all you need is to pick colors from the last row:

2. Yahoo Image Search

Only few people know that Yahoo can be the best Flickr image search engine you’ve ever tried; mainly, because it has some useful search option that Flickr doesn’t. One of them is actually Black&Whit photos. Both options are accessed via Advanced search; there you can set the image color (black and white) and image source (check Flickr to only include photos from Flickr). Right there, you can also set the license filter to only search for images available for distribution:

3. Corbisimages

Corbisimages is my preferred stock images search engine that both contains a high-quality selection of creative photography and offers a robust search feature with lots of features. I first learned about it from this image search engines overview by Edward Khoo and it has been my personal favorite since then.

Besides setting it to search through black and white images only, you can filter:

• By Type (photography or illustration);
• By distribution rights (royalty-free or “rights managed”);
• By editorial type (current news, documentary, fine art; entertainment):;
• By orientation (horizontal, vertical, panorama);
• By date when the photo was created;
• By photographer.

4. Bing Image Search

As an avid Googler, I feel bad listing both Yahoo and Bing and not mentioning Google; but here’s the truth: I love Google general search, I hate Google images search. It is both limited and irrelevant. I prefer Bing Image Search engine.

It has plenty of great search options (including a black and white filter):

• Search by size (small, medium, large, wallpaper);
• Search by layout (squire, tall, wide);
• Search by style (photography or illustration);
• Check special people search filters: just faces or including head and shoulders.

Besides, it offers a similar search option if you hover your mouse cursor over an image.

5. Picsearch

Picsearch is a good alternative image search engine to have by hand (the tool was already mentioned in our alternative image search overview). It doesn’t have any extraordinary search options to mention. The only reason I use it from time to time is that it provides totally different search results – something I’d never be able to find using ordinary tools like Google or Yahoo.

Picsearch uses its own search index and operates its own “unique search technology”:

Picsearch uses its own technology to crawl the web and has created a searchable index of images…. Picsearch image search technology has three main features that make it unique. It has a relevancy unrivalled on the web due to its patent-pending indexing algorithms. Also, Picsearch has a family friendliness that allows children to surf in safety as all offensive material is filtered out by our advanced filtering systems. The site is also very user friendly as it’s designed to be simple, fast and accurate.

Besides searching for black and white photography, the tool offers a few other nifty features like:

• Filtering by size;
• Filtering by type (landscape versus portrait for example);
• Showing search suggestions.

What are you favourite image search engines? Tell us about them in the comments.原文