Cloudinary Blog

Blog posts of 'Ruby-on-Rails' tag
Dynamic ZIP files generation with a single line of code

As a developer, you want to allow your users to download multiple files in a single click. An easy way to download multiple files and share them is to generate a ZIP file. When images are involved, you may also want to normalize the original images before including them in the ZIP file, by scaling them down to the same maximum resolution or converting them to the same format.

In the following simple example, 3 images of cats have been uploaded to the cloud.

fat_cat kitten hungry_cat
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Apply conditions to dynamically manipulate images.

It's great to have the capability to manipulate images on the fly by using dynamic URLs to customize the images to fit the graphic design of your site or mobile application. However, what if you want to manipulate an image depending on a specific image characteristic (like its width or aspect ratio) or its contents (does it contain a face?). What you need is a way to apply a transformation to an image only if a specific condition is met. Take for example a situation where you have allocated space on your page for a user uploaded image with a width and height of 200 pixels. Furthermore, if the image contains a face you would like to zoom in and focus on the face itself, otherwise you would like to fit the entire image into the available space:

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Powerful facial detection for image manipulation

Many of the photos displayed on the internet these days are of people. If your website or mobile application displays photos that include people, you will want to make sure that their faces are included in the delivered images when cropping and manipulating them to fit your graphic design and responsive layout. You may even want to further manipulate an image according to the faces present, for example, adding a harlequin mask overlay on all of their eyes, where each mask is adjusted to the correct size and orientation (although not a typical use case, it's a cool example of using advanced facial attribute detection):

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Dynamically distort images to fit your graphic design

It can be quite a challenge to graphically design a website or mobile application that displays images in very precise shapes and orientations. This can take the form of warping 2D pictures to have a 3D perspective, placing images in precise shapes or overlaying images in specific locations within another image, for example: overlaying an image over the screen of a smartphone.

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Automatic image tagging and categorization

If you have an application that allows users to upload their own photos, it can be very useful to be able to organize these photos according to their content. This will allow you to categorize the content for displaying to all your users and make your image library searchable. Furthermore, you can also learn more about your users according to the content they upload and find different trends of what people care about. Other added benefits can also include the ability to display matching content to your users according to their interests or even match them with other users that share similar interests.

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How to generate waveform images from audio files

by Meir Feinberg
How to generate waveform images from audio files

Many social networks, websites and messaging applications allow users to upload a wide variety of media files, and although the majority of files are in the form of images and video clips, a significant minority are audio files. When the website or application subsequently needs to display a thumbnail that describes the uploaded content, images can be cropped and resized down to scale, and a single frame from a video clip can be converted to an image and then also cropped and resized down to scale.

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5 ways to optimize images for effective social sharing

As a website/app developer or owner, you’ve undoubtedly experienced your fair share of glitches and mishaps when it comes to users or site visitors sharing your content. Many outlets such as news and media sites, social networks, or e-commerce sites include the option to "like" or "share" content such as blog posts or images. Once shared, the social network site displays a snippet of the shared content alongside a featured image. This way, your site content gets maximum exposure in social networks and attracts additional visitors.

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Google's new logo might not be as small as claimed

The Internet was abuzz last week after the announcement of Google’s new logo. What caught our eyes more than the artistic changes was this sentence on Google's blog: "building a special variant of our full-color logo that is only 305 bytes, compared to our existing logo at ~14,000 bytes". Sounds exciting! But is it correct?

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Transcode, convert, resize, crop and manipulate videos

Videos are becoming more prolific with people having the capability to capture videos with a wide variety of cameras, including smartphone cameras that are available almost everywhere. Web and mobile applications that display videos online can be faced with a challenge when the videos are created or uploaded from different devices and in various formats, and then need to be delivered in a multitude of resolutions and aspect ratios to various web browsers, laptops and all kinds of mobile devices in HTML5 web friendly video formats.

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Lossy compression for optimizing animated GIFs

by Meir Feinberg
How to optimize animated GIFs with lossy compression

Animated GIFs keep getting more and more popular, but they are generally very big files with slow loading times and high bandwidth costs, while the format itself is quite old and not optimized for modern video clips. As developers, you need to allow users to upload their animated GIF files, but you also need to deliver them optimized, which can be a complex, time consuming process.

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Automatic visual image enhancement for web apps

Various factors can have an effect on the visual quality of photos captured by a wide variety of digital cameras. Technical limitations of cameras, coupled with changing conditions in which users take photos, results in a wide range of visual quality. Camera-related limitations arise from a combination of poor optics, noisy sensors, and the modest capabilities of mobile camera phones that are used to take photos in conditions that range from bright daylight to indoor scenes with incandescent light or even dark night scenes.

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