I've got a couple questions about the use of images in a html document that I couldn't find an answer for.
Why is the standard 12x12 / 24x24 / 48x48 / 96x96 /... and not 8x8 /
16x16 / 32x32 / 64x64 / ... ?
Why is a 130x130px image resized to 50x50px by the browser (by
setting its width/height in the html doc) going to be more blurry
than a 100x100 image resized to 50x50 ? (is it just easier for the
browser to divide the size by 2 ?)
Is there a specific resolution for images that is worth using over another to be
more 4k friendly ? For instance using 384x384px images instead of
96x96 for 4K screen owners ?
1. Why are there icon size standards?
First of all there are no "standard" sizes for icons but it is always a good idea to create icons with a equal ratio = square images. That does not mean you are not allowed to break the rules, but it depens for which medium you are creating the icons. Android using a differend base size then iOS, because they need to support different resolutions. For desktop it is always good to start from a scale of 16px as a base. reference for icon sizes
2. Why get images blurry when resizes?
Image you are the browser and you need to repaint your 120x120px pixel image into an 50x50 canvas. The problem you face right now is that you need to decides on several point which color to choose especially on edges? What the browser does ist to mix up colors for edges where he knows there is not more enoug space to display it crisp. This is causing the "blurry" effect. No think about resizing the 120x120 to the half. Thats a lot more easier because you dont need to mix colors anymore. Or in more technical term:
Well rastered images when scaled in either direction are going to have some anomalies. When you make them bigger, it’s obvious – things get pixelated quickly. When you shrink them down, whatever is rendering it has to guess on what pixel goes where. https://css-tricks.com/forums/topic/scaling-down-images-with-css-makes-them-blurry/#post-188194
3. Are there a specific resolution for images
Thats basicly a very good question and opens the topic of "responsive" Images. As you know the pixen density on 4k Monitors / Smartphones is a lot higher then on regular screen. The fact that images cannot scale the informations by themself makes them pixelated when enlarged and blurry when shrinked. Best case would be to use SVG as often as you can, icons are best usecase for icons. Normally just putting the bigges image online would do the task, but performancewise it would be catastrophical. If you want to master this topic I can give you some good links to dive in:
https://css-tricks.com/optimizing-large-scale-displays/
https://css-tricks.com/responsive-images-css/
Hope thats answers, at least, a bit of your worries :)
Related
I am new to web development and I have a question regarding the natural size of profile pictures vs their actual size.
I noticed that when I inspect element on the profile pictures on popular websites, the natural size of the avatar image is usually twice as large as the displayed size.
Some examples:
And when trying this out on my own, I noticed that images do really look better when you make sure the actual (natural) size of the image is twice as large as the displayed size.
As you can see the 64x64 picture looks a lot more crisp than the 32x32 picture. My question is if there is anything special about the two-factor. Can I make it a 128x128 picture and display it as a 32x32 to make it look even better?
Most images on the web are bitmap1 images, which are made of hundreds of thousands of pixels. For example, a 32x32 image would have 32*32 = 1024 pixels. To display the image, the browser would have to go through every single pixel in the image. So the more pixels in the image, the longer it takes to load it.
As for why the image looks better or clearer is because the number of pixels in the original image (natural size) is the same no matter how much you zoom in or out of the image.
So when you zoom in on an image, you get the following result:
(Image from http://scientificcuriosity.blogspot.com/2006/09/how-is-digital-photo-stored.html)
The "squares" you see are individual pixels.
But if you zoom out, you get the opposite effect:
(Image from https://www.researchgate.net/post/How_can_we_quantify_postural_stability_when_a_human_is_standing_without_perturbation_and_with_it)
As you can see, the image is much more clear when scaled down.
But, there is a major disadvantage to large images (in terms of width and height, or number of pixels), they take longer to load.
The more you scale down an image, the more crisp it will look, but also smaller.
Your best option is to use a medium-sized image and display it scaled at 50% to 100%.
[1] https://en.wikipedia.org/wiki/Bitmap
Image clarity works on the pixel, if you using the high-resolution image for a small display it's not a good idea because High-Resolution image size is big always. your website will be slow.
you can go with this For Example - Natural Size (64x64)px and you can show in (50x50)px not the big difference of Image Pixel.
it will also show your image clear.
I've an original image which is shown here. This is a HD image which is saved as jpg format. jpg is a lossy format which compresses the image when loaded on websites. So I saved the image as .png and tried to view it in my website, but the image was blurred. I even increased dpi of the image in paint.net, but the image was still blurred in my website.
Here is a screen shot of my website:
I want HD image to be shown in website without any blur. How can I do it?
Start with a higher resolution original image
I assume you are working from the similar looking template image, and the smartphone's screen has been added in after? The original image you linked to is only 600x212 pixels which is a very small size to work from (smaller than many mobiles, iphones and tablets). You need to start with a much larger and higher resolution image, and shrink it down as needed. Starting with a smaller image and increase the resolution or dpi cannot increase the quality since no extra details are added - often this just makes images worse.
This image is the same background but slightly larger at 850x300. Any editing like adding the app's image should be done at this larger resolution (it can easily be shrunk later but this will keep the quality as high as possible). Placeit.net sells the 1920x1440 version of the image for only $8 which should be large enough and scale down well.
JPG vs PNG
JPG is designed for photos and doesn't lose much, PNGs can be too large which affects load times, which are very important for mobile users. A high resolution JPG is the best approach examples and explanation. Every separate edit made to a JPG reduces the quality a little, so starting with the largest resolution image and doing a single edit is best. The resizing can be left to the web browser and responsive CSS.
Responsive CSS
This allows you to use the same HTML for both desktops and different sized mobile devices, with minimum changes which are controlled by a separate CSS file. Bootstrap and foundarion are the most population. Effectively you keep the key images at their largest size, then add media queries to the CSS to check size of the mobile device or desktop and adjust sizes accordingly. Images can also have their size specified in relative units, eg percentages. This css-only resizing is fast and efficient.
Google's image optimization guide covers lossy vs lossless, tools for fine tuning, scaling images and more. This points out that lossy/raster image formats are fine for very complex images like photos since human eyesight cannot perceive every detail anyway. What is 'lost' from the image is not normally noticable to the human eye - presuming of course you start with a high quality image.
Other options: progressive jpg and base64
Progressive JPGs appear to load faster than JPGs because they initially load in a way that looks like a lower quality image and then increases in quality, see example. Base64 is mostly used for small images like icons and 'above the fold' images that need to load quickly, although they can be demanding on memory. The image is stored using a very long alphanumeric string embedded in your CSS or webpage code rather than as a separate file. More details here
Frist you must ensure you original picture is clear enough and have high dpi
Second you must notes that nowadays the smartphone screen definition is much higher than common PC, so your picture must have enough definition.
Third, your cellphone browser mustn't have cloud speeding. Some cellphone like Opera may lead to image compression.
At last, I recommend you use high-quality jpg format image. You must keep a balance between size and definition.
I would come straight to the point:
PNG image or JPEG if forced to resize over its current form will produce lower quality output. Best way is to use 1600px wide and whatever length image you have and use image optimization softwares such as OptiPNG, PNGQuant or XnView and compress the output image to gain substantial ammount of compression.
Something about dpi
It won't affect too much for desktop browsers, and meanwhile if yu have an image with initial dpi of 72, there will be no gains to put image over 72 dpi after it.
The solution i use
Most of the time, we work on illustrator for graphics, so we build SVG from them. SVG is scalable till the end of screens, no loss of quality at all. As far as PNG and JPEG are concerned it is much better to use larger dimension image and compress it will tools. There is one great online tool for this stuff Kraken
One beautiful Trick
In photoshop, gimp: try sharpen your image. Sharpening will increase edge contrast and you can hack around from bad surce image too.
As far as base64 is concerned, it is bad idea to put an HD image of around 110 KB's in code, every time user open's your site will get your 110KB wasted, let them be stored in cache through either css: .class{background:url('image'); position:cover;}.
The only way to get better results is by minimizing http request but that is too much of headache. As only method right now is too make a image sprites.
If you want an HD image then you should download an HD image and edit it in Photoshop where you can solve all your requirements bcoz it's the way it goes in industries.
See this:
http://real-sense.com/index.php?option=com_content&view=article&id=106
The set of vertical images on the right are being resized using CSS
.thumbnail-product-resize
{
width:144px;
height : auto;
}
Does anyone know how to do this in a cleaner way so I don't lose quality on the image?
I mean that if I had resized the image using photoshop, the text won't appear as blurry as it does here.
Tested in FF
Thanks
The quality of your images will depend on the original size of the image you use. If have a large image with good quality, say of size 400x500, and it is then resized in the HTML to 80x100, it will still be a 400x500 image. However you can only fit a certain number of pixels on a smaller image of 80x100, so this bigger image has to be sampled. This means that an average is taken of pixels and then made to represent a 80x100 size image.
If you want a more definite result you can change to original size of the image to 80x100. This will probably give you better results.
Once upon a time browser image resizing gave truly heinous results due to the unsophisticated nearest neighbor technique they used to scale images. Now they usually perform filtering when scaling and there isn't that much difference between in-browser resizing and resizing in Photoshop.
The real advantage to scaling an image before serving it to the client is that you aren't forcing the download of large images when they aren't necessary. Depending on the size of your images, this can significantly reduce your page load times.
One final thing to consider is that more and more people have devices with "retina" displays. For those users scaling the image before serving it will result in much less crisp images.
Here's an in-depth comparison of the image scaling methods used by various browsers: http://entropymine.com/resamplescope/notes/browsers/
Even if you had done this in photoshop those images you have would still appear pretty much the way do just now.
FYI you don't need to include height:auto in your CSS above.
Best bet would be to create a seperate set of thumbnails (using photoshop) which maybe just show a portion of the image.
Loading the thumbnails and resizing them with css the way you are doing is bad practice as you are still having the user download the large images first.
It is impossible to shrink an image without loosing quality unless it is an vector-image. That would mean that you'd have to use SVG. And considering the images displayed I don't think you wan't to do that.
Also you mentioned the cleaner way to do it, use photoshop or something similar.
When I'm scaling down big images using canvas and drawImage method, the result is far from perfect.
Compare this images. Left one is actually the canvas with scaled image and the right one is a desirable result. Original of this images is 1600x900 photo. Scale goes from original size to 200x113.
When original image have less width and height or scaling ratio more (ie 0.5 - 0.9), then all fine. But I need to get my users ability to resize big images and make nice thumbnails.
I tried to scale image with multiple small steps (for example 1600px -> 1000px -> 500px -> 200px), the result was better, but it's very bad for perfomance, so I refused this.
If achievement of my goal using HTML5 and canvas now isn't possible, is there any chance that in future it will? I'm just thinking whether should I refuse HTML5 technology and make uploading on ActionScript or keep trying (or waiting) to do this with HTML5? I like HTML5 and actually I don't want to leave such a friendly technology.
The left image was scaled down using a more-primitive form of re-sampling or interpolation. This may be entirely due to how the browser's rendering engine happens to scale images, with the results varying from browser to browser.
If it's an option, one approach where you have full control over the resulting image quality is to upload the image, scale it on the server, and then download it back to the client.
Another approach is to use a JS library to resample the image on the client side. Not sure how practical that is.
I created a black and white collage consisting of a number of images - but saved the file as 1280*1024 - ideally encompassing that rez of a screen.
The issue is, would it be wiser to have the background scale, and stretch the images in the case of a larger screen or should I have it repeat so as not to lose resolution, and have smaller screens cropped from some of the background?
Thanks for any insight!
I personally don't think scaling an image up is ever an option. It's incredibly noticeable, and it doesn't look good. I would recommend using a background image that at least works on 1920 x 1080, and gracefully fade out the image on the edges or tiles well so if someone sees the page on an even larger screen, there aren't strong lines on the edges of the background.
If you are concerned about the bandwidth involved in large images, check out CSS3 Media Queries. All mobile browsers support this CSS3 module, and it will allow you to target certain resolutions and send them smaller images (both in dimensions and file size).
If your image does tile well, I would recommend going with the smallest pattern, and letting css do the repetition for you. There's no point in pushing more pixels down the pipe than necessary.
It's up to the user really but they obviously can't make that decision. I'd scale it but that's not as easy as tiling it. I've never successfully scaled a background image.
It will also depend on your preference.
Are you okay with having a stretched image as a background, in case the user has a larger screen? If yes, then by all means set the background image to stretch. Or, are you more keen on preserving the integrity of the image? In the latter case, it's much better to have the image tile.
If you're interested in creating a full page background image, try one of these techniques found on CSS Tricks: "Perfect Full Page Background Image".