resize image to browser proportionally checking width and height - javascript

I'm building a fluid website in which an image must scale to a maximum size depending on the viewport of the browser (minus some margins). I don't want the image to crop or lose its original proportions, so depending on the width or height it should resize to the maximum size possible without cropping.
I wrote some javascript code, but since I'm not a hardcore coder I was wondering how to fix this in the right way. The script works, but has a bug when resizing. It seems that it only processes one if statement when resizing the browser window.
function setSizes() {
var margin_top = 100;
var margin_right = 85;
var margin_bottom = 10;
var margin_left = 85;
// get image width and height
var img_w = $('.gallery_img').width();
var img_h = $('.gallery_img').height();
// calculate viewport width and height
var vp_w = $(window).width() - margin_right - margin_left;
var vp_h = $(window).height() - margin_top - margin_bottom;
//
if (vp_w <= img_w || vp_w > img_w) {
// new width
var img_w_new=vp_w;
// calculate new height
var img_h_new=Math.round((img_h*img_w_new) / img_w);
}
//
if (vp_h <= img_h || vp_h > img_h) {
// new height
var img_h_new=vp_h;
// calculate new width
var img_w_new=Math.round((img_w*img_h_new) / img_h);
}
// change image width and height to new width and new height
$('.gallery_img').width(img_w_new);
$('.gallery_img').height(img_h_new);
}
// onload
$(window).load(function(){ setSizes(); });
// on resize
$(window).bind("resize", function() { setSizes(); });
I searched for a solution for quite some time, but most scripts I found only check and change the width.
Does somebody know how to fix this?
Thanx!

this might be a lame answer but why don't you just use css width setting?
see http://jsfiddle.net/dXm4r/

I think this is a wrong approach? It would be more natural to define width of enclosing container in percents and than define width 100% on image. Something like this:
div.img-container {
width: 30%;
}
div.img-container img {
display: block;
width: 100%;
}
<div class="img-conatiner">
<img src="...
</div>
Please pay attention to the fact that in img CSS rule there is no height specified, this will allow browsers to properly scale image without loosing quality.

You have a line to change the width; simply add a line to change the height, based on your height variable. You can figure out what the height should be by dividing the new width by the old width. Basically, that is the multiple of widths in the new width, which is equal to the multiple of heights in the new height. Therefore, if you multiply that number to the old height, you would get the new height.
Here is the equation you could use:
img_h_new = (img_w_new / img_w) * img_h;
And this is the function you could use with your width function:
$('.gallery_img').height(img_w_new);

http://blog.francois-becker.net/post/2012/08/16/HTMLCSS-container-of-a-maximized-image

you can done it by css ,just apply this css to your image element
.img { /* image*/
position: absolute;
top: 10px;
right: 85px;
bottom: 10px;
left: 85px;
width: calc( 100% - 170px); /* 170 = marging left + right*/
height: calc(100% - 20px); /* 20px = marging top + bottomt*/
background-size: cover;
box-sizing: border-box;
padding: 0px;
}
body { /* container*/
margin: 0px;
padding: 0px;
height: 100%
width:100%;
overflow:hidden;
}
<html>
<body>
<img class="img" src="http://kingofwallpapers.com/picture/picture-004.jpg" > </img>
</body>
</html>

Related

Maintain aspect ratio of a video when resizing the browser

I'm working on a Video editing tool, and I need to maintain the 16:9 aspect ratio of the video when resizing the screen horizontally and vertically. So far I got it to work as expected when resizing horizontally, and when resizing down vertically, but can't get it to work when sizing up vertically. The Javascript code I used to calculate the height of the video and resize it is below (notice how the else clause is empty because that's where the code should go):
const calculateHeight = () => {
// Get the other elements on the page
const header = document.querySelector('.main-navigation');
const meshTopBar = document.querySelector('.mesh__top-bar');
const footer = document.querySelector('.mesh__bottom-bar');
// Get the section to apply the window height to it
const mainSection = document.querySelector('.insert-level-container');
// Get the video elements
const editor = document.querySelector('.mesh__insert-editor-container');
const video = document.querySelector('.mesh__insert-editor-video-container');
// Apply the height to the main section by calculating the window height minus the other elements' height
if(mainSection !== null) {
mainSection.style.height = (window.innerHeight - header.offsetHeight - meshTopBar.offsetHeight - footer.offsetHeight) + 'px';
}
// This should be the ideal height for the video
video.style.minHeight = ((video.offsetWidth * 9) / 16) + 'px';
// If the video height is bigger than the section height (calculated above), then resize it
if(video.offsetHeight + 115 > mainSection.offsetHeight) {
video.style.minHeight = video.offsetHeight - 1 + 'px';
editor.style.maxWidth = video.offsetHeight * 16 / 9 + 'px';
} else {
// This is where the logic for the vertical resizing should go
}
}
The relevant CSS for these items is:
.mesh__insert-editor-container {
margin-left: auto;
margin-right: auto;
}
.mesh__insert-editor-video-container {
position: relative;
width: 100%:
}
And the HTML:
<section class="mesh__insert-editor-container flex__one flex-container flex-column horizontally-left-aligned" id="video-main-container">
<div class="mesh__insert-editor-video-container flex-container horizontally-right-aligned flex-wrap">
<video class="mesh__insert-editor-video-placeholder"></video>
</div>
</section>
All this code is:
Get the height of all the elements on the page, sum them and calculate the main section height by subtracting that height;
If the video height gets bigger than the section height, I reduce its height by -1px each time the window gets resized, and calculate the new width.
All the above code is giving me this result, which works great for most scenarios, but I need the video to size up when the condition on the if statement is not met. Everything I tried inside the else statement gets "jumpy".
Any better alternatives to solve this would be much appreciated. Thanks all!
The CSS aspect ratio trick might be a good solution: https://css-tricks.com/aspect-ratio-boxes/
The approach takes advantage of a quirk in CSS where padding based on a percentage value will be relative to the element's width. Create a container using this trick, the important bit is this line:
padding-top: calc(9/16 * 100%);
The value is calculating the correct height based on the aspect ratio you want (9 tall over 16 wide in this case) and generating it relative to the width of the element by multiplying by 100%.
With the container maintaining aspect ratio, just place the content inside an absolute positioned inner div and you should be good. This solution is fully responsive at that point.
* { box-sizing: border-box }
.outer-max-width {
max-width: 960px;
margin: 0 auto;
}
.aspect-ratio-box {
width: 100%;
padding-top: calc(9/16 * 100%);
position: relative;
border: 2px solid red; /* for demo visibility, remove */
}
.aspect-ratio-box-content {
position: absolute;
width: 100%;
top: 0;
left: 0;
border: 2px solid blue; /* for demo visibility, remove */
}
.video-placeholder {
display: block;
width: 100%;
height: auto;
}
<div class="outer-max-width">
<div class="aspect-ratio-box">
<div class="aspect-ratio-box-content">
<img class="video-placeholder" src="https://placeimg.com/640/360/nature" />
</div>
</div>
</div>
Got it to work! I used this amazing CSS-only solution: https://codepen.io/EightArmsHQ/pen/BvNzrm similar to BugsArePeopleToo's suggestion, from eightarmshq:
.content{
position: absolute;
top: 0;
bottom: 0;
width: 100%;
height: 100%;
background: #555;
box-shadow: inset 1vh 1vh 10vh 0 rgba(0,0,0,0.5);
display: flex;
box-sizing: border-box;
border: 25px solid #cecece;
}

How to give image a max-height but retain aspect ratio?

The image is 100% of the document width. I want the max-height of the image to be 2/3 of the screen height but to retain aspect ratio, and for the image to be centered.
Here is a Fiddle for a starting point.
EDIT: I've updated the fiddle to demonstrate one CSS solution I found (shown below in answers) but it would be preferable to have a solution that has more browser support.
Html:
<header>
<div class="header-content"></div>
</header>
<div class="image-wrapper">
<img class="image" src="http://designyoutrust.com/wp-content/uploads/2013/06/376.jpg" alt="pic" />
</div>
<div class="other-content">
</div>
CSS:
header {
width: 100%;
border: 1px solid black;
box-sizing: border-box;
}
.header-content {
height: 5em;
}
.image {
width: 100%;
}
.other-content {
height: 20em;
width: 100%;
background-color: black;
}
I've just started learning web development so I'm very new to all this. I've tried creating a function that says if image height >= 67vh then html width = image width but I couldn't get it to work.
This solution works although I would rather have a solution with better browser support.
.image-wrapper, .image {
max-height: 67vh;
}
body {
max-width: 119.0525vh;
margin: auto;
}
The max-width was calculated with the aspect ratio of the original image in relation to viewport height.
Calculation is (image width / image height) * percentage of viewport height = max-width
In this case (1354px / 762px) * 67vh = 119.0525vh
image {
display: block;
max-width: 119.0525vh;
max-height: 67vh;
width: auto;
height: auto;
}
source: CSS force image resize and keep aspect ratio
most common way I make is using div's background instead of img, set background-size 100% and leave height empty, it will keep aspect.
html:
<div class="image"></div>
css:
.image {
width: 100%;
height: 100vh;
background-image: url(http://designyoutrust.com/wp-content/uploads/2013/06/376.jpg);
background-repeat: no-repeat;
background-position: center center;
background-size: 100%;
}
If you application is intent to use any king of image in terms of aspect ratio and resolution. Then you can use below concept:
HTML:
<img src="#Model.ThumbnailUrl" id="imageThumbnail">
Javascript:
<script>
$(document).ready(function () {
$('#imageThumbnail').each(function () {
var maxWidth = 601; // Max width for the image
var maxHeight = 257.14; // Max height for the image
var ratio = 0; // Used for aspect ratio
var width = $(this).width(); // Current image width
var height = $(this).height(); // Current image height
// If Height width are same
if (height === width) {
$(this).css("height", maxHeight);
$(this).css("width", maxHeight);
}
// Check if the current width is larger than the max
if (width > maxWidth) {
ratio = maxWidth / width; // get ratio for scaling image
$(this).css("width", maxWidth); // Set new width
$(this).css("height", height * ratio); // Scale height based on ratio
height = height * ratio; // Reset height to match scaled image
width = width * ratio; // Reset width to match scaled image
}
// Check if current height is larger than max
if (height > maxHeight) {
ratio = maxHeight / height; // get ratio for scaling image
$(this).css("height", maxHeight); // Set new height
$(this).css("width", width * ratio); // Scale width based on ratio
width = width * ratio; // Reset width to match scaled image
}
});
});
</script>
for setting div width according to image width try this:
var image = new Image()
image.onload = function(){
$('.image-wrapper').width = image.width
}
image.src = 'http://designyoutrust.com/wp-content/uploads/2013/06/376.jpg';

Center an image inside of a responsive viewport without it losing its aspect ratio

What I'm trying to do is to center and resize an image that's inside of a viewport (or a parent element), without stretching it.
To make a very long story short, I want the images to keep their aspect ratio and be resized so that they cover up the viewport completely.
This is my HTML layout:
<div class="media-area" data-size="b" data-type="2">
<ul class="content-slider">
<li class="cs-item">
<img class="cs-background" src="assets/img/backgrounds/top-slider-1.jpg" alt="slider-element">
</li>
<li class="cs-item">
<img class="cs-background" src="assets/img/backgrounds/top-slider-2.jpg" alt="slider-element">
</li>
<li class="cs-item">
<img class="cs-background" src="assets/img/backgrounds/top-slider-3.jpg" alt="slider-element">
</li>
</ul>
</div>
This is my CSS:
.media-area {
width: 100%;
height: 100%; /* Standard height */
position: relative;
overflow: hidden;
}
.media-area .content-slider {
position: relative;
margin: 0;
padding: 0;
width: 100%;
height: 100%;
}
.media-area .content-slider .cs-item {
position: relative;
display: block;
float: left;
margin: 0;
padding: 0;
width: 100%;
height: 100%;
}
.media-area .content-slider .cs-item img {
display: block;
}
.media-area .content-slider .cs-background {
-webkit-transition: all .1s ease-in-out;
-moz-transition: all .1s ease-in-out;
-o-transition: all .1s ease-in-out;
transition: all .1s ease-in-out;
}
And this is my JS:
function mediazone() {
var defaults = {
elem: ".media-area",
elemWrap: ".media-area .content-slider",
elemSlide: ".media-area .content-slider .cs-item",
vh: $(window).height(),
vw: $(window).width()
};
$(defaults.elemSlide).find(".cs-background").each(function () {
var bkndImgW = $(this).width(); // Current image width
var bkndImgH = $(this).height(); // Current image height
var mediaViewPortW = $(this).parents(defaults.elem).width(); // Current media viewport width
var mediaViewPortH = $(this).parents(defaults.elem).height(); // Current media viewport height
// Used for viewport aspect ratio
var viewportratio = Math.round((mediaViewPortW / mediaViewPortH) * 100000 ) / 100000;
// Used for image aspect ratio
var imageratio = Math.round((bkndImgW / bkndImgH) * 100000 ) / 100000;
// Negative margins for when the height is larger than the width
var bkndImgPosW = ((bkndImgW - mediaViewPortW) / 2)*-1;
// Negative margins for when the width is larger than the height
var bkndImgPosH = ((bkndImgH - mediaViewPortH) / 2)*-1;
bkndImgPosW = Math.min(0, Math.max(bkndImgPosW, bkndImgPosW));
bkndImgPosH = Math.min(0, Math.max(bkndImgPosH, bkndImgPosH));
if (viewportratio > imageratio) {
$(this).removeAttr("style");
$(this).css("min-height", "100%");
$(this).css("width", "100%");
$(this).css("margin", bkndImgPosH+"px 0px");
} else if (viewportratio < imageratio){
$(this).removeAttr("style");
$(this).css("height", "100%");
$(this).css("min-width", "100%");
$(this).css("margin", "0px "+bkndImgPosW+"px");
} else if (viewportratio == imageratio) {
$(this).removeAttr("style");
}
});
}
The function is initialized here:
$(document).ready(function () {
mediazone();
});
$(window).resize(function () {
mediazone();
console.log('window resize event');
});
The problem I'm faced with right now is that when the page loads, the image is half-way out of the viewport, but when I resize the browser window, it fits perfectly.
Another problem I can't really find a way around right now is the one with the two aspect ratio's being equal ( i couldn't find a way to make the image cover the screen without having to deal with some white spaces). This makes the image flicker when the aforementioned scenario is under way.
It is important that I use the IMG tag in the DOM, otherwise maybe there would have been a way to make use of the "background-image" property in CSS.
Can anyone point out what I'm missing/ doing wrong/ I should delete?
Kind regards,
Alex
* Later Edit *
This is what I have right now:
http://jsfiddle.net/LexEckhart/Z5cjx/
After resizing, it seems to work fine and maintain the image balanced in the middle but when the page loads, the items are not positioned properly.
Since the OP specifically said he didn't want to use background-image as the image must be present in the DOM as an image, here's a jsfiddle showing a solution. I've dimmed the images using opacity to show the borders of the li's beneath it. I think the OP was overthinking the problem a bit. Anyway, hope this helps.
jsfiddle
if (viewportratio > imageratio) {
$(this).removeAttr("style");
$(this).css("width", "100%");
$(this).css("margin", bkndImgPosH+"px 0px");
} else if (viewportratio < imageratio){
$(this).removeAttr("style");
$(this).css("height", "100%");
$(this).css("margin", "0px "+bkndImgPosW+"px");
} else if (viewportratio == imageratio) {
$(this).removeAttr("style");
}
Keep in mind that images retain their aspect ratio if you only provide one attribute / property (width OR height). That's the key to the solution.
EDIT: Updated fiddle. I played around with the math logic until it worked for the images I had, replacing your images which I used before. The math logic below the first section is possibly wrong, so it'll need further testing, but this works for what I had.
You can give try for
"background-size" and "align-items" properties from css3.
set "background-size:100% 100%;";
it will cover (parent window);
For aligning contents in center you could use "align-items:center".
You can take advantage of the fact that percentage padding is always figured from the element's width. You can therefore use vertical padding with a percentage width to enforce an aspect ratio.
<div id=img></div>
// ... then in CSS:
#img {
background: url("http://placekitten.com/1280/720") no-repeat center center;
background-size: cover;
height: 0;
padding-bottom: 56.25%; /* 9:16, or 720/1280 */
}
Here is a jsfiddle to demonstrate. If you don't know the aspect ratio in advance, you can of course compute it and set the "padding-bottom" dynamically via JavaScript.
Thanks are due to the inimitable Dave Rupert for this technique.
edit ah, the <img> tag in that ending paragraph was hidden. You can employ a variation of this trick if you really need an <img> tag:
<div class=image-centerer>
<img src='http://whatever.com/your/image.png'>
</div>
// ... then in CSS:
.image-centerer {
position: relative;
height: 0;
padding-bottom: 56.25%;
}
.image-centerer img {
position: absolute;
display: block;
height: 100%;
}
Fiddle demo, and here is one demonstrating the handling of arbitrarily-proportioned images.

displaying image of unknown size inside div of fixed size

I have a <div> of fixed size say height:100px and width:100px.
I have to display images of unknown size inside this <div> such that following cases arise:
image width > div width
image width < div width
image width = div width
image height > div height
image height < div height
image height = div height
no matter what, what is the best cross browser strategy, with support for legacy browsers, to display them with following criteria:
no white space around image
nicely centered (horizontally and vertically) if overflow
To eliminate white space, set min-height and min-width to 100% for the images. To clip the overflow, set overflow: hidden on the div. To center overflowing images, use absolute positioning and some JavaScript to set top and left values based on the size of the image.
Edit: If the image is larger than the container in both dimensions, use some JavaScript to remove the minHeight and minWidth and then set the height to 100%. If that leaves whitespace on the width, set height to "" and set width to 100%:
.centeredImageContainer {
height: 100px;
width: 100px;
overflow: hidden;
position: relative;
}
.centeredImage {
min-width: 100%;
min-height: 100%;
position: absolute;
}
function centerImage(img) {
var container = img.parentNode;
if (img.offsetHeight > container.clientHeight &&
img.offsetWidth > container.clientWidth) {
img.style.minHeight = "0";
img.style.minWidth = "0";
img.style.height = "100%";
if (img.offsetWidth < container.clientWidth) {
img.style.height = "";
img.style.width = "100%";
}
}
img.style.top = ((container.offsetHeight - img.offsetHeight) / 2) + "px";
img.style.left = ((container.offsetWidth - img.offsetWidth) / 2) + "px";
}
jsfiddle.net/QRU4w/2
edit:
fiddle
html:
<div id="myPic"></div>
css, if you want a big pic to shrink to fit while still filling the whole div, and want a small pic to expand to fill the whole div:
#myPic{
width: 100px;
height: 100px;
background-image: url(/abs/path/img.jpg);
background-size: cover;
}
css, if you want a big pic to only display a window of the middle without resizing:
#myPic{
width: 100px;
height: 100px;
background-image: url(/abs/path/img.jpg);
background-position: center center;
}
I don't know of a way to both expand small images to fit, while not shrinking big images.
If you mean that you need to have no whitespace including above a landscape-oriented image, for example (i.e. the photo needs to fill the square, regardless of whether it is originally a square), then you may want to look into setting the image as the div's background and using background-size: cover. See this link for browser support.
The best way to do this is by using object-fit property.
.image-container {
width: 400px;
height: 300px;
}
.centered-image {
width: 100%;
height: 100%;
object-fit: cover;
}
<div class="image-container">
<img src="https://24seven.co.ke/uploads/sliders/1550944223ecommmerce.jpg" alt="24seven Developers slider" class="centered-image">
</div>
For more illustrations and geeks see this.

Scale a div to fit in window but preserve aspect ratio

How can I scale a div to fit inside the browser view port but preserve the aspect ratio of the div. How can I do this using CSS and/or JQuery?
Thanks!
You don't need javascript for this. You can use pure CSS.
A padding-top percentage is interpreted relative to the containing block width. Combine it with position: absolute on a child element, and you can put pretty much anything in a box that retains its aspect ratio.
HTML:
<div class="aspectwrapper">
<div class="content">
</div>
</div>
CSS:
.aspectwrapper {
display: inline-block; /* shrink to fit */
width: 100%; /* whatever width you like */
position: relative; /* so .content can use position: absolute */
}
.aspectwrapper::after {
padding-top: 56.25%; /* percentage of containing block _width_ */
display: block;
content: '';
}
.content {
position: absolute;
top: 0; bottom: 0; right: 0; left: 0; /* follow the parent's edges */
outline: thin dashed green; /* just so you can see the box */
}
The display: inline-block leaves a little extra space below the bottom edge of the .aspectwrapper box, so another element below it won't run flush against it. Using display: block will get rid of it.
Thanks to this post for the tip!
Another approach relies on the fact that browsers respect an image's aspect ratio when you resize only its width or height. (I'll let google generate a 16x9 transparent image for demonstration purposes, but in practice you would use your own static image.)
HTML:
<div class="aspectwrapper">
<img class="aspectspacer" src="http://chart.googleapis.com/chart?cht=p3&chs=160x90" />
<div class="content">
</div>
</div>
CSS:
.aspectwrapper {
width: 100%;
position: relative;
}
.aspectspacer {
width: 100%; /* let the enlarged image height push .aspectwrapper's bottom edge */
}
.content {
position: absolute;
top: 0; bottom: 0; right: 0; left: 0;
outline: thin dashed green;
}
Thanks to Geoff for the tip on how to structure the math and logic. Here's my jQuery implementation, which I'm using to size a lightbox so it fills the window:
var height = originalHeight;
var width = originalWidth;
aspect = width / height;
if($(window).height() < $(window).width()) {
var resizedHeight = $(window).height();
var resizedWidth = resizedHeight * aspect;
}
else { // screen width is smaller than height (mobile, etc)
var resizedWidth = $(window).width();
var resizedHeight = resizedWidth / aspect;
}
This is working well for me right now across laptop and mobile screen sizes.
I have a different pure HTML/CSS approach which does not rely on padding or absolute positioning. Instead it uses em units and relies on the CSS min() function plus a little bit of math.
Imagine that we want a viewport div with 16:9 aspect ratio which always fits the browser window and is centered in the axis with excess space. Here's how we can accomplish that:
HTML
<body>
<div class="viewport">
<p>
This should be a 16:9 viewport that fits the window.
</p>
</div>
</body>
CSS
body {
width: 100vw;
height: 100vh;
margin: 0;
display: flex;
justify-content: center;
align-items: center;
background-color: white;
font-size: min(1vw, 1.778vh);
}
div.viewport {
width: 100em;
height: 56.25em;
background-color: lightblue;
}
div.viewport > p {
font-size: 3em;
text-align: center;
}
You can experiment with this in a sample JSFiddle here.
The secret sauce is in the body font-size. It should be set to min(1vw, Avh), where A is the aspect ratio you want the div to have, i.e. width / height. In the example above we're using 1.778, which is approximately 16 / 9.
In CSS, em units are based on the font-size of the element, which is inherited from parent element if not explicitly set. For your viewport div, set the width to 100em (NOT rem) and the height to Iem, where I is the inverse of the aspect ratio expressed as a percentage, i.e. 100 / A or 100 * height / width. In the example above we're using 56.25, which is 100 * 9 / 16.
One bonus of this approach is that all of your nested elements may also use em units so that they always scale precisely with the size of the viewport. You can see this used on the p element in the example.
Note that as an alternative to the above, you may set the font-size on your html element and use rem units everywhere. CSS rem units are similar to em units but always relative to the root element's font-size.
Javascipt:
//Responsive Scaling
let outer = document.getElementById('outer'),
wrapper = document.getElementById('wrap'),
maxWidth = outer.clientWidth,
maxHeight = outer.clientHeight;
window.addEventListener("resize", resize);
resize();
function resize(){
let scale,
width = window.innerWidth,
height = window.innerHeight,
isMax = width >= maxWidth && height >= maxHeight;
scale = Math.min(width/maxWidth, height/maxHeight);
outer.style.transform = isMax?'':'scale(' + scale + ')';
wrapper.style.width = isMax?'':maxWidth * scale;
wrapper.style.height = isMax?'':maxHeight * scale;
}
HTML:
<div id="wrap">
<div id="outer">
{{ fixed content here }}
</div>
</div>
Styling:
/* Responsive Scaling */
#wrap {
position: relative;
width: 1024px;
height: 590px;
margin: 0 auto;
}
#outer {
position: relative;
width: 1024px;
height: 590px;
transform-origin: 0% 0%;
overflow: hidden;
}
This is possible with JQuery and a bit of maths.
Use JQuery to get the view ports width and height as well as the divs current dimensions.
$(document).width();
Calculate the divs current aspect ratio. eg width/height
You need a bit of logic to determine whether to set the width or height first, then use the initial ratio to calculate the other side.
jQuery has a plugin that grows an object until one of it's sides reaches a certain px-value. Coupling this will the viewport's height, you could expand any element to that size: jQuery MaxSide.

Categories

Resources