I'm sure I poorly structered that question title, but this is what I'm trying to do:
Key: image = moving picture behind submit form
Problem 1: Get the background image to stay at that perfect size no matter the width of the page.
Get the entire frame of the moving image showing.
When the image is at the perfect width (http://gyazo.com/702e443a6b814b1abc26a801836f4d6f) it shows the entire image.
When the width is increased even more, the image starts to 'zoom in'. (Which I don't want.)
Problem 2: On mobile devices with much smaller screens, most of the image is cut off (and you can't scroll to see the rest).
Get the entire frame of the moving image showing.
Have the entire image centered and the user should be able to see the entire frame of the image.
This is what my code looks like for the image:
background-image: url("https://s-media-cache-ak0.pinimg.com/originals/a4/79/4c/a4794cbfe048505d9645339738a8ddc7.jpg");
height: 60%;
background-size: 100%;
background-repeat: no-repeat;
background-size: cover;
jsfiddle
You need to do the following:
#top{
background-image: url("https://s-media-cache-ak0.pinimg.com/originals/a4/79/4c/a4794cbfe048505d9645339738a8ddc7.jpg");
height: 60%;
background-position: center -150px;
background-repeat: no-repeat;
}
Because you were using the background-size: 100%; you're telling the browser to scale the image for you. By removing it and positioning the background you'll achieve what you want with the image never resizing.
Fiddle
Note: You'll need to make sure that your image is large enough that when the page is stretched really large that you won't see the background. It will be hard to do, given that screen resolutions are getting so large now.
#your_image_container_id {
width: 100%;
}
What you are trying to say is called "Responsive Web Design". In order to achieve RWD, you never use absolute units such as pixels, points... but rather use relative units such as %, em which scales according to size of the screen. but you have do some calculation though such as %, make sure all elements on same row do not have the total of with percentage of over 100%, or something like that and also have to compensate for paddings and margins.
Visually I can appreciate the difference, but in which situations should I prefer one over the other?
Is there any point using them at all or can they be replaced by percentages?
Currently I don't seem to be able to go beyond a trial-error approach when using these properties, which does my head in.
Also I can only find pretty vague explanations and especially I find the W3C doc quite baffling.
Values have the following meanings:
‘contain’
Scale the image, while preserving its intrinsic aspect ratio
(if any), to the largest size such that both its width and its height
can fit inside the background positioning area.
‘cover’
Scale the image, while preserving its intrinsic aspect ratio (if any), to the
smallest size such that both its width and its height can completely
cover the background positioning area.
I'm probably being a bit thick, but can anyone give me a plain English explanation with relative examples?
Please use this fiddle. Thanks.
CSS
body{
width:500px;
height:500px;
background:url(http://upload.wikimedia.org/wikipedia/commons/1/1a/Bachalpseeflowers.jpg);
background-size:contain;
background-repeat:no-repeat;
}
Note
The accepted answer is the one I currently find the most concise and complete.
Thanks everybody for their help.
You can consider looking at the pseudocodes that govern the output. The values allotted to the image's size depend directly on the aspect ratios of container wrt aspect ratio of the background image.
Note: Aspect ratio = width / height
Contain
if (aspect ratio of container > aspect ratio of image)
image-height = container-height
image-width = aspect-ratio-preserved width
else
image-width = container width
image-height = aspect-ratio-preserved height
Cover
if (aspect ratio of container > aspect ratio of image)
image-width = container width
image-height = aspect-ratio-preserved height
else
image-height = container height
image-width = aspect-ratio-preserved width
You see the relation? In both cover and contain, aspect ratio is preserved. But the if - else conditions reverse in both the cases.
This is what makes cover to cover full page, without any white portion visible. When aspect ratio of container is greater, scaling image so that its width becomes equal to container width. Now, height will be greater, as aspect ratio is smaller. Thus it covers the whole page without any white portion.
Q. Can they be replaced by percentages?
No, not simply by percentages. You'll need conditioning.
Q. In which situations should I prefer one over the other?
When you are creating a website, you wouldn't want any white portion in the fixed background. So use cover.
contain on the other can be used when you are using a repeating background (e.g. when you have a pattern image with very high aspect ratio wrt veiwport/container you can use contain and set background-repeat to repeat-y). But a more appropriate use for contain would be for a fixed height/width element.
Although the question assumes the reader already understands how the contain and cover values for background-size work, here's a plain-English paraphrasing of what the spec says, which can serve as a quick primer:
background-size: contain ensures that the entire background image will fit the background area, keeping its original aspect ratio. If the background area is smaller than the image, the image will shrink so that it can fit the background area. If the background area is either taller or wider than the image, then any parts of the area not occupied by the main image will either be filled by repetitions of the image, or letterboxes/whitespace if background-repeat is set to no-repeat.
background-size: cover makes the background image as large as possible such that it will fill the entire background area leaving no gaps. The difference between cover and 100% 100% is that the aspect ratio of the image is preserved, so no unnatural stretching of the image occurs.
Note that neither of these two keyword values can be expressed using any combination of lengths, percentages, or auto keywords.
So when do you use one over the other? Personally, I think cover has more practical uses than contain, so I will go with that first.1
background-size: cover
One common use case of background-size: cover is in a full-screen layout where the background image is rich in detail, such as a photo, and you want to feature this image prominently, albeit as a background as opposed to the main content.
You want just enough of the image to be able to completely cover the browser viewport or screen, regardless of the aspect ratio of the viewport, or whether the image or the viewport is in portrait or landscape. You're not concerned if any parts of the image are cropped out as a result of this, as long as the image fills up the entire background area and maintains its original aspect ratio.
Here's an example of a layout where the content is housed in a semitransparent white background, which hovers over a full-screen background. When you increase the height of the preview pane, notice that the image automatically scales up to ensure that it still covers the entire preview area.
html {
height: 100%;
background-image: url(http://upload.wikimedia.org/wikipedia/commons/1/1a/Bachalpseeflowers.jpg);
background-position: center center;
background-size: cover;
background-repeat: no-repeat;
background-attachment: fixed;
}
body {
width: 80%;
min-height: 100%;
background-color: rgba(255, 255, 255, 0.5);
margin: 5em auto;
padding: 1em;
}
If you use background-size: contain instead, what happens is that the background image shrinks in order for the entire image to fit in the preview pane. This leaves ugly white letterboxes around the image depending on the aspect ratio of the preview pane, which ruins the effect.
background-size: contain
So why would one use background-size: contain if it leaves ugly blank spaces around the image? One use case that immediately comes to mind is if the designer doesn't care about the blank spaces, so long as the entire image fits within the background area.
That may sound contrived, but consider that not every image looks bad with empty space around it. This is where the example of using a logo instead of a photo actually demonstrates this best, even though you probably won't find yourself using a logo as a background image.
A logo is typically an irregular shape sitting on either a blank or completely transparent background. This leaves a canvas that can be filled by a solid color or a different background. Using background-size: contain will ensure that the entire image fits the background without any parts of it being cropped out, but the image still looks right at home on the canvas.
But it doesn't necessarily have to apply to an irregularly-shaped image. It can apply to rectangular images as well. As long as you require that no cropping of the background image occurs, whitespace can either be seen as a reasonable tradeoff, or not a big deal at all. Remember fixed-width layouts? Think of background-size: contain as essentially that, but for background images and in both portrait and landscape orientations: if you can ensure that the content will always fit the boundaries of the background image at all times, then whitespace becomes a non-issue altogether.
Although background-size: contain will work whether or not the image is set to repeat, I can't think of any good use cases involving repeating backgrounds.
1 Note that if you're using a gradient as a background, both contain and cover have no effect because gradients do not have any intrinsic dimensions. In both cases, the gradient will stretch to cover the container, as though you had specified 100% 100%.
background-size:cover will cover the entire div with the image. This could be useful for showing thumbnail images of a main image where the entire image being displayed isn't that important, but you still want to conform to a size for all images. (for example, a blog post excerpt)
background-size:contain will show the entire image within the div. This can be useful if you specifically want to display the entirety of the images, but within a set container div size. (For example, a collection of company logos)
Both keep the image at the same aspect ratio
http://cdn.onextrapixel.com/wp-content/uploads/2012/02/cover-contain.jpg
background-size:contain;
When using contain you may still see white-spacing, due to the way that it sizes and contains itself within the element.
background-size:cover;
will completely cover said element, you will not see any white-spacing
source:
http://www.css3.info/preview/background-size/
see example H
edit: use background-size:contain if:
You want it so that your image is always displayed in the viewport. Please note that: while you can see the full image, it will leave white spacing either on the top or bottom of the image whenever the aspect ratio of the browser and window are not the same.
use background-size:cover if:
You want a background-image, but you don't want the negative effect of the white-spacing which contain does have, please note that: when using background-size:cover; you may experience that it will cut off some of the image.
source: http://alistapart.com/article/supersize-that-background-please
Contain:- Scale the image to the largest size such that both its width and its height can fit inside the content area.
Exmaple:
Cover:-Scale the background image to be as large as possible so that the background area is completely covered by the background image. Some parts of the background image may not be in view within the background positioning area.
Example:
We had a huge conversation about cover vs contain just want to share this thoughts:
landscape image on landscape screen - best to use cover
portrait image on landscape screen - best to use contain
portrait image on landscape screen - best to use contain
portrait image on landscape screen - best to use contain
Illustration:
if(iDonPutSomeCode) const result = iCantPasteLinkToCodePen
https://codepen.io/Kinosura/pen/EGZbdy?editors=1100
Currently, I have a mockup website www.hush.technology
and on my windows (17 inch) computer the website background is full screen
but on my mac (13 inch ) the width of the picture is cut off on the right. I generally like to solve problems on my own but I can't figure it out.
my css looks like this
// CSS CODE
.bgimage {
background: url(image url);
background-size: cover;
width: auto;
height: 720px;
}
Would anyone know why this is happening. I would love an explanation.
From here
background-size:cover
Scale the background image to be as large as possible so that the background area is completely covered by the background image. Some parts of the background image may not be in view within the background positioning area
I assume the aspect ratio is off, and it is clipping part of the image.
I'll try to build on what both of these answers have said. But I'll tell you in short: there is no solution to what you're trying to achieve because it isn't possible. Here's why:
The first box from the left shows what you have as a full screen browser - your image background perfectly covers the screen as you want it to. Your screen is the same size as the background and the image ratio is kept.
The box in the middle shows what happens when you resize your browser (or view on your 13" mac, which I'm assuming is a lower resolution). The image gets cut off the left and right! But why? Because the image is doing what it's been told to: keep it's ratio and cover the entire screen. They both have to be met, and the background image doesn't care whether all of itself isn't visible - it just cares that the screen is being covered and the ratio is the same.
The final box (one on the right), is the implementation of user3739658's answer. You've told the image you want it to make itself entirely visible, and keep the ratio. The consequence: it can't cover the whole screen anymore.
Your background image can only be guaranteed to do two of the three at any given time.
Cover the screen
Keep the ratio
Show the entire image
Another panel I could show is the image being told to: cover the screen and show the entire image, which would result in the image being stretched one way or the other.
The Solution
The easiest thing to do is to remove your static height: 720px;, which means the div can now resize based on the width of the browser (to keep the ratio of the background image).
An alternative is to change your background's purpose - your image is mostly made up of three things:
The actual picture on the right
Some largish text on the top left
Lots of background colour
You can split the background up into just having a picture on the right, and text on the left, with your background now being just a colour. The advantage of this is that the image will always show at the right of the screen, and your text will always show (and is now no longer a picture). Both the text and picture will also never skew, since the property being resized is the background color's width: which doesn't matter since its just a colour fill.
Check this link;
Perfect Full Page Background Image
html {
background: url(images/bg.jpg) no-repeat center center fixed;
-webkit-background-size: cover;
-moz-background-size: cover;
-o-background-size: cover;
background-size: cover;
}
good luck!
first of all keep in mind I uderstand a very little of HTML language...
if you answer, do it as if you'd do it to a 10yo boy...
The question:
I'd like to have a background image in my website and another one on it.
the bg's image can be freely resized to match the screen or mobile size,
but the second one should keep its aspect ratio....!
http://www.flickr.com/photos/110747328#N03/
![you'll see on the left the full screen size and on the right the mobile size][1]
I dont know if understand you correctly. Here's what I get:
You want your bg image to be dynamically resized according to the size of the screen, but not the "content".
You can get the first by using the "background-size: cover"'s CSS property for your background:
body {
background: url('path-to-your-image.jpg') no-repeat center center fixed;
background-size: cover;
}
After that, if you just create a div and put your content in it. You'll get what you want: for the background to be resized and the content to keep its proportions.
Here is a live example: http://jsfiddle.net/agarridob/8NtwE/
By the way, I strongly recommend that you take a look at http://www.bentobox.io, where you'll find lots of resources that will help you understand a bit of what this HTML & CSS is.
I've never dealt with a website like this before, but here's what I'm trying to accomplish...
I have one large image (1000px x 1000px) which I want to use for the background image. The content itself only takes up around 500px x 500px, and It needs to be on the same position all the time relative to the background image.
This is complicated to describe, so I'll make a picture:
This itself doesn't seem like it would be that hard, but what if the browser is larger than my 11" screen? If the browser is too big for the background image, I'd like a simple color to show.
The other problem I see is keeping it centered at all time with scroll bars not appearing as they should only appear if the browser window is smaller than the content box.
I'll be happy to clarify more, as I'm having trouble putting into words what I'm trying to accomplish.
use CSS:
HTML{ width:100%; height:100%;
background:#F00 url(path/to/your/image.jpg) center center no-repeat;
background-attachment: fixed;
background-size:100% auto;
}
background sums up background-color, background-image, background-position and background-repeat (in that order). The other two currently cannot be included in background (though the W3C spec says otherwise).
background-attachment:fixed is like position:fixed for layers and will assure that the image stays visible regardless of how the user scrolls. if you don't want that, wrap a container around your content and assign the above declaration to it instead of to the HTML-node
background-size scales the image into your background
play with the value a bit - what I proposed here will scale the image to fit to the width of the viewport. 100% 100% will stretch it to always cover the entire viewport and auto 100% will scale it to fit into the height of the viewport. In both cases that use auto some clipping might occur - or the background-color (I chose red) will show on the sides/top&bottom
giving the HTML-node width:100%;height:100% makes sure you don't have a white border on the bottom if your content does not fill the screen
Not clear what problems you are having. Here is an example of what you might want to do: http://jsfiddle.net/mhgdZ/