I have an 40px by 20px image with 72 Pixels / Inch.
I would like to create a Retina display version.
What should I do? Double the size? Change the resolution?
And in which format should I save it? PNG? JPG? ...
I am using this image on a web site ...
In your image editor, double the size of your image to 80px by 40px.
In your markup set the width to 40 and height to 20.
<img src="example.png" width="40" height="20" />
You should save as png if you need transparency or the image is line art. Save photographs as jpg.
My answer is convert your image into SVG
Do you have Illustrator? If so save your image as SVG (and have a png as a fallback if you want).
<img src="images/logo.svg" alt="" />
<img src="images/logo.png" alt="" />
As long as you use Modernzr which can work to get svg friendly in most browsers.
You can see it here how it's done:
http://toddmotto.com/mastering-svg-use-for-a-retina-web-fallbacks-with-png-script/
Hope it helps :)
A retina display image (or high-density display image) is double the pixel size of a standard image - its scaling factor is 2.0. This means that yes, for your 40x20 pixel image, you will need to make an 80x40 pixel version (that is then displayed at double pixel density on screen). The format doesn't matter as much, both PNG and JPG will work fine (PNG will not degrade in quality with compression, but the file size will be larger than JPG).
However, the problem with high-density display images is that they take up more bandwidth, and are unnecessary for devices that don't have the high resolution or Retina displays. This means more data transferred over the network, inconveniencing mobile users and those with limited data transfer caps.
One solution is to use something like Retina.js. It's an open-source javascript client script that will automatically load the retina-sized image from your server and swap it in-place for the low-density version, if it exists. It follows Apple's standard for naming high-resolution images - #2x, so you can have HTML code like this:
<img src="/images/my_image.jpg" />
and the script will search your server also for /images/my_image#2x.jpg. If it exists, it will load it and swap it in-place without having to worry about messing with CSS.
Generally as of this writing there are two types of retina displays, hence you should create an image for each type.
For a 2× device, you would need to produce twice the logical pixels' width and height with a resolution of 144 pixels per inch (72 ppi ✕ 2).
For a 3× device, you would need three times the logical pixels with a resolution of 216 pixels per inch (72 ppi ✕ 3).
Examples of 2× devices are the MacBook Pro (released in 2012-2019) and most iPhone since the iPhone 4. Examples of 3×
devices are the iPhone 6 Plus, and the iPhone X. However the iPhone Xr is a 2× device.
Hence for your case you would need images in 80 px ✕ 40 px and 120 px ✕ 60 px for 2× and 3× devices respectively.
Retina displays are not dependent on the specific bitmap image format. You can use the original image format. For websites, you should use JPG for photographs and PNG for line-art graphics saved as bitmaps.
You should not just blindly enlarge images otherwise this would create a blurred results – it would no better than if you don't include any high-resolution versions in the first place. Either obtain the original higher-resolution version of the images (typically from vector graphic source) and downscale them or use a machine-learning based image enhancement solution such as Bigger Picture to "convert" your image into a higher resolution.
Photoshop gives you a couple options for resizing an image. For instance if the image is iPhone size you can increase the image size by 200%. Photoshop gives you a couple options for resampling of the image. Bicubic, bilinear and etc. This will remake the image at a higher resolution and interpolate the missing pixels. Hope this helps.
This is a really interesting article showing a nice option for dealing with high res images:
http://blog.netvlies.nl/design-interactie/retina-revolution/
Basically, it's saying that, if you make the image quite large (width and height) but then save it at quite low quality, it still comes out very sharp on retina displays. It means that you can use the one same image on all devices, and that the file size is very low, too, which is an extra bonus. You can set the width and height of the image in your CSS and/or HTML to set it to the visual dimensions you desire.
This article blew me away, and is my go-to approach for dealing with both retina-friendly and bandwidth-friendly images. Win, win.
You can use CSS opacity option.
This will give you an transparent look of your image based upon the value you set to opacity.
Try learning opacity: http://www.w3schools.com/css/css_image_transparency.asp
Related
Is there a way to fix the Retina Blurry icons on cellphones without using the 2x sizing images hack?
I'm a Front-End developer and the Designer is not avaibable to giving me the icons of the Website at the double of its size.
So, I was wondering if there is any way to keep the original icons size and make it looks correctly on cellphones with Retina display.
Small pixel images are automatically enlarged by the browsers and the quality of the anti aliasing is depending on the rendering engine of the browser.
If you don't want to use the media queries #2 trick you could use svg icons instead as vector graphics are cristal sharp on every screen resolution and ppi.
Edit: As mentioned in the comment below you can disable antialias in browsers as described here: Disable antialising when scaling images
But that will not create eg a sharp round circle out of a 16 pixel graphic as the pixels will still be squared pixels (just enlarged)...
How can I force mediawiki to disable resizing and use the original size of my image? My main problem is that I'm uploading small parts of screenshots. If I don't use the original size then they look awful. (Imagine a 237px wide image resized to 400px....) But I don't see any option for that.
http://www.mediawiki.org/wiki/Help:Images#Size_and_frame
By simply using the image name, it will fit the image to screen which is really bad! For example, a 300px wide screenshot cutout looks awful on a full hd monitor... You could say that the image may be too large for the users' screen but in my particular case that is not the case. I'll always be using small images (300px and smaller) and the users will always watch these pages on desktop monitors.
I'm sorry I was very dump. If I don't use any option then it is displayed in its original size. I was mistaken because somebody has changed the zoom level of my browser, but I did not realize this because the monitor resolution was so high...
I want all images for a mobile site to be 640px wide, based on iPhone screen size.
All images should be the full width of the screen when shown img { width: 100%; height: auto; }.
For the images that are smaller than 640px wide, is it better to use the above CSS to scale them up, or should I use Photoshop or something to scale the actual image up? Does it even make a difference?
So does scaling up an image using CSS result in a better or worse image quality than using something like Photoshop to increase the size?
Scaling images up doesn't go well for the quality of said images, you need to sort out your priorities on this one. You can work on those images and increase the quality and size of those images in Photoshop so you don't lose any quality when resizing, but this will increase page loads or you could lose some quality, but improve page loads with smaller but more crappy images.
If you really want to target each device (computer vs mobile) perfectly you can use javascript to switch out the images. This can be done really easily using http://foundation.zurb.com/docs/components/interchange.html or similar libraries.
If the images are graphics or icons I might suggest just making them svgs and using those instead as they are crisp at a greater range of resolutions. If you go with this option its best to make their sizes multiples of two.
I'm building a page which is supposed to be full retina ready. I'm creating a retina version of all the small-medium images.
It looks good when you look at the 100x100 pixel version of a 50x50 image on devices with high density screens. But what if the image is much larger? Like a background image of a slider with 1700x600 pixel dimensions, should this get a retina version as well? The image's size is already much bigger than almost every mobile device's resolution. Would a 1700x600 or a 3400x1200 image look different on a 640x960 display?
Don't forget about retina enabled laptops, and iPads... In my experience most images you can save at a scale of about 150% the expected viewing size, and they still look great on a high density screen. You should play with compression quality as well, a lot of times you can lower the quality and still have an image that looks great because of the shear amount of extra pixels.
See this for an example of what I'm talking about: http://filamentgroup.com/lab/rwd_img_compression/
I notice that when I measure out something in Photoshop to "ensure pixel perfection" it's usually half of what's measured in Photoshop to go to CSS. So if I measure at 60px, in CSS it goes to 30px.
But only roughly so.. Is there a way to make sure it matches 100% so I don't have to guesstimate? And why does this happen?
When you are measuring out those pixels in Photoshop, you have to make sure you know what size your resolution is. For the web, it uses 72 dpi resolution, check in Photoshop under "image size" to see what resolution your image is. Sometimes images are at 300 dpi which if you use that and then try to save on the web will make the image larger than it should be.
In Photoshop:
Ctrl + N > Web tab > Web Most Common
This Artboard will set the settings to be fir for webpages. Now screenshots from the browser should match the PS pixels values.
Also make sure that your browser settings haven't changed the zoom ratio or font size.