What I've noticed about some sites that rely on heavy images (such as google maps)
is that they display a low-rez copy of an image and then when you focus on a certain section of that image they generate a high rez copy of the image. That seems easy enough. But what confuses is me is that they only render a specific section of that image and not the entire image. How do they go about doing this? (Rendering sections of an image at a time)
Each "section of an image" is actually an individual image that is loaded separately from other images.
If you view your network details when browsing google maps, you'll see things like this
being transmitted, which is a small piece of the whole map that is displayed on the screen.
Related
I have several high-resolution images that I am using on my website. I am using PHP to echo the images. I specify a width of "30" for each of the images, which correctly sizes them.
The problem is that for SOME of the images, there is some sort of automatic conversion to data URI - which seems to cause the images to not only be resized to 30x30, but also to have a resolution of 30x30.
This seems to happen when I refresh - almost like it is caching the php after the first execution, then on refresh, it thinks the image file size is actually 30x30.
See images below - the first image is the first time I visit the website and screen captured on my iphone. Then I refresh, and the second screenshot is the result. Notice that the apple image remains crisp on both, while the rest appear blurry. All of the original files have approximately the same resolution.
Additionally, if I view the apple image (after refresh) in it's own window, it shows this:
.../logos/30xNx50de0713c94d847...
Whereas if I view the "dicks sporting goods" image in it's own window, it shows this:
data:image/jpeg;base64...
I am not specifying any kind of data URI conversion - would it be something on the server that does this automatically? And why for some images but not others?
Thank you for your time.
I determined this was a result of PageSpeed being enabled on my host. PageSpeed is a Google product that optimizes the loading of pages - and in this case, transforms images based on the width that is specified in the img tag.
By adding
?ModPagespeed=off
to the end of any page, it disables PageSpeed and shows the images at full resolution. I took this approach rather than disabling PageSpeed entirely, because I want some of my pages to take advantage of the optimization.
In my project, users can write books online and save it as a epub file. I need to implement a functionality which enables the user to see the preview of epub file. There will be two tabs in preview page. One is for kindlefire and other is for ipad. I have saved all the datas (XHTML, css, content, etc) of epub file in the database. The preview should give the exact look of the book in kindlefire and ipad. Is it ok to use normal html and css to generate preview of book ? If there is any other straight forward method for this, please suggest me
I think that you shouldn't aim for the EXACT look on those devices, instead just view the html and css (of course, test it on those devices anyway). People usually don't mind if there are small differences like gaps or paddings somewhere, the main thing is text anyway. Unless, of course, you have difficult tables and media content.
I Googled a lot but no sufficient ans was found.
I need to place an image (900 X 5200 px) in one of my pages. As the image is sensitive, I need to prevent users from copying the image. I have an idea that can do this:
I will divide the image into pieces. Then the image grid will be loaded into some divs. So user won't be able to save the image. Or he/she will save only 1 square cm part of the whole image.
But this plan will not work if some small parts of the grid fails to load. So, I want to do another thing. I want to load the full image then cut the image into parts. Then show the parts altogether in divs.
This requires javascript. But I am confused how to start and need your help.
Now you know the matter, if you have better idea please share.
Thanks in advance.
The trick is simple. Create a div with the background being the image you want to display. Layer a div with a transparent image over it. When user goes to save the image, they get a blank. Program your server to not return "direct" requests for the image (so some clever chap can't just look at the css and retrieve the URL to the image).
Granted the image will still be in their cache but so would the sliced image so it won't make it impossible just more difficult for a determined person to retrieve the picture.
TL;DR Don't over engineer a solution, print screen will get around anything you do.
You are not going to be able to prevent people from copying this image. Plain and simple. Regardless of your best efforts, a simple PRT SCRN and paste into Paint will be enough.
Your best bet will be to not over engineer this and simply place a watermark and copyright notice on the page. Other options can include placing a transparent <div> over the top of the image so it cannot be right-click'ed and saved, but it still will not prevent the image from being stored in the user's cache. Or stop them from using developer tools or Firebug to find the source image.
You can do this with:
http://www.pixastic.com/lib/docs/actions/crop/
Yet you need to develop your logic around that library.
I have made example, you can see it on this link:
http://simplestudio.rs/yard/crop_img/
Basically you can get URL to your image via php and using my code or code similar to it crop your image into pieces and display them on canvas.
This way image is not accessible via browser or inspect element or what so ever. User can save the pieces individually but you can configure my code for piece to be 5px, I set it to 20x20px.
* test saving image piece by doing right click anywhere on image and do a "Save image as.." option.
Also you need to think of way how to hide src to image provided by php, if you need help on that I can help you.
I'm displaying pieces of an image in a large grid created from divs. I'm using the background-image and background-position to display portions of the image. The problem I'm running in to is that a user can simply open up firebug and see the entire image (which defeats the purpose of the game).
I've attempted to mask the path using a php script as the URL but if the user navigates to the php file, they can still see the image. It would appear that anything I do with the CSS is entirely client side so denying everything outside the localhost in my .htaccess won't work.
Any suggestions?
The over arching goal is to have an automated way to split and display pieces of the image into a grid.
If you deliver the whole image to the browser, the browser holds the image and has every right to show it to a user. I don't think you can prevent the browser from showing it. I'm afraid you will have to deliver the image in pieces, or perhaps write your whole game using <canvas> and play around with images as pixel data. :)
I'm working on a website for a specific client. And he wants to be able to add link to the website, and on mouse hover to have a image of that website appear.
Now, he doesen't want to take an image of the website, he only wants to input the link and have the website do everything else.
So my question is ->
Is there a way (eg. google API) to get a website image only by providing the url via php?
Sort of like in google, when you hover over a lik of a page, a tooltip pops up to the right with an image.
Any help is, as always, appriciated :)
Here is a list of 10 free thumbnail services
http://www.webresourcesdepot.com/10-free-website-thumbnail-generation-services/
You can simply refer to the URLs of these services, e.g.
<img src="http://SnapCasa.com/Get.aspx?code=[code]&size=[size]&url=[url]" />
or make a CURL call from one of your PHP scripts and temporarily store/permanently save the image that was generated.
Have recently developed Thumbnailspro.com. It is currently free to use while in beta testing as we work out the bugs, but so far its getting quite popular, you can request thumbnails directly from your website using the code below :
http://thumbnailspro.com/thumb/http://msn.com&s=150
s=Size, size can be anywhere from 10 to 1000 pixels just add s=300 to display a thumbnail 300 pixels in width. We are trying to add more options as we go for thumbnail requests and at the same time trying to keep it as simple as possible so you don't have to enter something like the code below to get your thumbnails :
http://somethumbnailsite.com/viewurl.php?url=http://msn.com&x=200&y=300&bwidth=1024&bheight=768&rotate=76&what_the_hell%20_is_all_this_crap!
So is much more effecient!
Like the service or have any bugs contact us at admin#thumbnailspro.com!
No. The only way to do this is to request the HTML for the page, render the page and then create a thumbnail from that page render. Google does this because in the process of spidering the web, they already get all that data, and they've got a nice optimized rendering engine (Chrome) that they can put the data through, and then they've got tons of online storage space to store the cached image. There's a lot of work there, though.