Basically exactly what the question asks. Do images on a website download the full file before re sizing them. I have a bunch of pictures and I use html to resize the images down to thumbnails to easily display on the page. However, these images take way to long to load while they are only 100px x 100px big. My only explanation is that it is downloading the entire file before re sizing.
Yes. The full image is downloaded.
If the source url is 1000x1000 and you size it on the screen to 100x100, it still has to load the entire image.
You should store the thumbnail at 100x100 and the full size at 1000x1000 and reference each when appropriate.
Related
I have a website where people can upload images. I have seen that a lot of sites scale down images to thumbnail size and show that on a search page for example, until the user actually clicks on one to view it in full size.
Why is it good practice to generate a thumbnail version of an uploaded image? Why not just use img tag with set height and width?
[EDIT]: After reading a few answers, I realised that I have probably phrased my question poorly. So, what I mean is, are the images downloaded in full size, even if they have a size specified in CSS? Are they scaled down at rendering after the page has finsihed loading?
Thanks!
Larger images have larger file sizes. If you have 1MB images but only need to show thumbnails that might be 10KB in size, you'll be saving 99% of your bandwidth by only showing the full images when required.
In addition to bandwidth, clients often have limited memory... think of mobile devices. Plus, the CPU required to handle them during scrolling and what not.
If you use the img tag with width and height, that picture is still the original, the data size does not change (it only looks smaller in your browser).
If you have thumbnails, those thumbnails are smaller in data size but usually somewhere on your page you link them to the original with bigger data size.
If the user downloads the thumbnail, he'll get the small sized picture, if he downloads the original, he gets the big sized.
Note: A thumbnail is a different picture than the original.
Are the images downloaded in full size, even if they have a size specified in CSS?
Yes images will be downloaded in origin size (full size). CSS only changes view of image not main image file.
Are they scaled down at rendering after the page has finsihed loading?
No, except when there is a script to do such job.
Smaller image has smaller size = faster loading.
When user actually want to see image, you open actual image and it may wait for load.
If you have several posts on search and each has image, thumbnails will be much faster to load than original images.
If you scale down original image with css (set width and height) it will still need to load original image first.
I am trying to build a deals page which are pulled from amazon.in.I basically go to a deal and copy the image and upload to my server.
But due to different size of the images on amazon.in when I shrink it by 200*200 size for the deal thumbnail, some of the images are getting distorted.
In the below image you can see that the Amazon Basics cable is properly scaled, where as the iphone 7 image is distorted due to the nature of images at amazon.in.
What is the general recommendation for these problems? How do we solve this issue so that I get uniform images for my deals?
If the image does not have an aspect ratio of 1:1 (which is the ratio for your thumbnails) it will get distorted because there's more length in one dimension than the other and if try to match them, one of them will have to be squeezed. That's where the distortion comes from.
The only thing that will work is to give the images a new aspect ratio that matches your template
This can be done with CSS like #SaidbakR mentioned in the comments
Fix the width and place the image in a div with oveflow:none and fixed height to hide the extra height.
This will work beautifully but some images will just not work. They will just be cutoff in the wrong places.
The only other thing you can do is to manually edit the photos in Photoshop or something similar. This can work on all images, but manually editing each and every photo that doesn't fit is a pain in the neck.
nevertheless, here's what you end up with.
Before: Original Image in full dimensions
After: Image edited in a program like Photoshop to the desired size of 200x200 with no distortion
So? My Suggested fix is to adjust your approach/template or find another source for your images.
I have img background in my angular app, in slow connections the image loads slow and shows partially during the loading.
Is there a way to wait until the image fully loads and then to show it? and not to show it in loading progress?
Most likely it is caused by the size and resolution of the image.
To make it load faster reduce image sizes using either GIF, PNG-8. or JPEG as the file formats. Make sure the size matches your usage and set the size for each page with the height and width. Do not make use of scaling, especially from larger to smaller images. The image result might look fine on screen but the file size will be the same. To truly take advantage of the smaller dimensions, use an image editing program and scale the image accordingly. Also play around with different image compressions.
When I have an <img> that is smaller than the original image, will the file automatically be resized? Or will the user have to load the entire image?
For example, I have giant wallpaper files, but I only show thumbnails that are 100px by 100px. Am I doing something inefficiently by just setting the <img> width and height to 100px?
Yes. The browser has to download the entire image file and then scale it.
Yes, whole image will load and then scaling will be there.
Why don't you search before asking a simple question.
If you google it you can easily get this answer.
I would suggest next time please do some Google and practice it on any editor before you ask any questions that will give you hands on experience.
Answer :- Whole image will be loaded and whole image will be automatically re-sized, Yes it is not good practice to use big amount of size to small scale of image height and width
I have site where in I do client side image thumbnail preview with HTML 5 file reader interface.Everything works perfectly.However I see when I upload large size images lets say 600 by 600 , Image quality gets bad.I can understand that I shrink the size of the image and then display it.My image thumbnail placeholder is 300 by 300 and users can upload any size of the images.I need to maintain the quality of the images as given by the users.Is their anything I can do to maintain this on the client side ?Please read all dimension on pixels.
When I compare work with say facebook thumbnails, facebook thumbnails looks good even if they are shrunk in size.Appreciate if someone can point me to right direction.
There are several techniques to reduce image dimensions that differ in the way the image is re-sampled. See if you can control the re-sampling method to change it to "Bilinear". "Nearest Neighbor" re-sampling tends to give out ragged looking images when reducing.