Cropping the top 10% of an image using CSS? - css

Question

How to crop the top of an image has already been described in this question. However, I am trying to crop an image by a percentage when the image dimensions are not known ahead of time. The container's resulting height should then be dependent on the size of the image.
Using the following, I can crop the top of an image, but it requires manually specifying the amount of the image to show in pixels. Is there a way I can specify I want to crop the top 10% of the image without knowing the image size ahead of time?
.container {
overflow: hidden;
position: relative;
height: 370px;
}
.container img {
position: absolute;
margin-left: auto;
margin-right: auto;
bottom: 0;
left: 0;
right: 0;
}
<div class="container">
<img class="img" src="http://placekitten.com/400/500" />
</div>

Answer 1

Here is an idea that rely on scale. You keep the image in-flow (don't use position:absolute) then you scale the container by 0.9 which is 90% of the total height then you scale the image by 1.1 to keep it's original size. This will trim the image by 10% but since transform is only a visual effect you may have space at the top or the bottom of the container (based on the transform-origin)
.container {
overflow: hidden;
outline:1px solid red;
display:inline-block;
}
.container img {
display:block;
}
.cut {
transform:scaleY(0.9);
transform-origin:top; /* The extra space will be on the bottom*/
}
.cut img {
transform:scaleY(1.1);
transform-origin:bottom; /* This should be bottom to cut the top*/
}
<div class="container">
<img class="img" src="http://placekitten.com/300/200" >
</div>
<div class="container cut">
<img class="img" src="http://placekitten.com/300/200" >
</div>
To be more precise we can consider calc() like below:
.container {
overflow: hidden;
outline:1px solid red;
display:inline-block;
}
.container img {
display:block;
}
.cut {
transform:scaleY(0.9);
transform-origin:top; /* The extra space will be on the bottom*/
}
.cut img {
transform:scaleY(calc(1/0.9));
transform-origin:bottom; /* This should be bottom to cut the top*/
}
<div class="container">
<img class="img" src="http://placekitten.com/300/200" >
</div>
<div class="container cut">
<img class="img" src="http://placekitten.com/300/200" >
</div>

Answer 2

I think the best approach to this without Javascript would be to translate the image up a certain percent, then scale it to fill the original height of the container. Anything else will leave a gap at the bottom.
.img_container img {
transform: translateY(-50%) scale(2);
}
https://jsfiddle.net/amoliski/n4ojdzyr/

Answer 3

This should do the trick, using translateY (got that from How can I get the height of an element using css only)
As you can see, the .container does not have a hardcoded height, however, it will load with the original image height, which is 500px, even though the image is loading as 450px (500px - 10%)
.container {
overflow: hidden;
position: relative;
}
.container img {
margin-left: auto;
margin-right: auto;
bottom: 0;
left: 0;
right: 0;
transform: translateY(-10%);
}
<div class="container">
<img class="img" src="http://placekitten.com/400/500" />
</div>

Answer 4

You can do this with a little bit of JavaScript (I've inlined it for simplicity's sake but you could move it to it's own function)
<div class="container">
<img class="img" src="http://placekitten.com/400/500" onload="javascript:this.parentElement.style.height = (this.height * 0.9)+'px';" />
</div>
Here's a working JSfiddle.

Answer 5

An alternative would be to use the top CSS property in a negative fashion on a relative image like the snippet below. This works for an image of an arbitary width and height. Just adjust your top value, accordingly.
html,body{ height:100%; margin:0; padding:0; }
.container {
overflow: hidden;
position: relative;
height: 100%;
width: 100%;
display:flex;
margin-bottom: -10%;
align-items:center;
justify-content:center;
}
.container img {
position: relative;
bottom: 0;
left: 0;
height: 100%;
top: -10%;
right: 0;
}
<div class="container">
<img class="img" src="http://placekitten.com/400/500" />
</div>
To remove the extra bottom margin, just subtract the margin-bottom equal to the amount you subtracted from the top. Here it is margin-bottom: -10%;
Adjust the top value according to your dynamic images. Also note, I added height:100% to your container so you can see the full image but the top part is cropped. I used flex for centering. Test for another image but this time, it is cropped 50% from the top
html,body{ height:100%; margin:0; padding:0; }
.container {
overflow: hidden;
position: relative;
height: 100%;
width: 100%;
margin-bottom: -50%;
display:flex;
align-items:center;
justify-content:center;
}
.container img {
position: relative;
bottom: 0;
left: 0;
height: 100%;
top: -50%;
right: 0;
}
<div class="container">
<img class="img" src="https://www.fujifilm.com/products/digital_cameras/x/fujifilm_x_t3/sample_images/img/index/ff_x_t3_002.JPG" />
</div>