I would like to show a few small sized images and a background on one of the screens in my application. What are the best practices to do it and avoid to see white windows before the images get drawn? Should I load all images in the beginning and keep them in memory, and then draw them when it's necessary? Or perhaps there are other ways to solve this issue?
Try this:
$('#loader_img').show();
$('#main_img').on('load', function(){
$('#loader_img').hide();
});
load event get executed when image finishes loading till then you can show loader image.
And instead of asking a question without try, you better try first and share the problem you are facing
Related
I am currently using Xamarin.Forms and I would like to import an image and be able to add markers to it. Similar to what the mapping apps do, but want to be able to do it from an uploaded image or from taking a photo. I would also Like to be able to set a scale on it after the image was uploaded by placing two or more markers and then entering a measurement between those markers.
When displaying an image/photo I would like to place markers on them that would have more info about the pinned location on the image. These pins must be saved in a database so that the next time it's opened the markers will be in the correct location as they were placed the first time.
If anyone knows how I can get started on this, or know of any libraries that allow you to this, it would really be appreciated.
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Update
Loading the image from file, camera or url is simple enough.
Zooming in and out after the image is loaded was simple enough too. Altering the scale size of the Image by making use of the PinchGesture.
Moving the image around ended up being simple too, and it was achieved by using the PanGesture and altering the TranslationX and TranslationY.
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.......Still searching for a working and reliable solution for adding Pins/Markers at a location on the image and the markers need to have a click or tap event attached to it.
I am developing an application for viewing images.
I used the example of PhotoScroller Apple to implement this application.
In my application I want to be able to draw on the image.
I had the idea to put a UIView on top with transparent background and draw the lines via touch events. This solution has become very slow because the generated images are very large, around 3700x2000 pixels.
I also tried a solution with the example of Apple GLPaint that uses OpenGL, but it has a size limitation of 2048x2048 pixels.
Anyone have any idea or example of how I implement this?
I think you should try and tile your image.
One option is using CATiledLayer. Have a look at this short tutorial.
Or you could try and use CGContextDrawTiledImage to get your stuff done. Possibly this post from S.O. could help you getting started.
I am trying to setup a "rotating image" for part of a site I am working on. I have taken many photos of a single item (30+), and I want to display them like it is a rotating 3D image (with a possible draggable speed).
One approach I have taken is setting it as a CSS background, and looping through the images every 0.1s. It works alright, but it flickers like crazy until the image has done a full rotation (I am assuming this is because the image is not yet cached)
Has anyone implemented something similar or have a suggestion?
Much appreciated.
jQuery Cycle is an amazingly versatile, light-weight, jQuery plugin.
http://jquery.malsup.com/cycle/
I added image to canvas element, but visitor than can save that image to local comp.
Is there any way to disable that option? I don't know, putting some transparent image over?
Thx
So i thought this can help you just disable rightclicks:
$('#canvas').bind("contextmenu",function(e){
return false;
});
None of this (not even image slicing) stops a user from simply copying the screen on to the clipboard and pasting it into MSpaint or any other image utility, and saving the result. Its trivial to do; And a transparency image is no impediment to this.
The only effective options that I know of are (as was said), watermarking or low quality.
*Avoid 1 pixel wide lines or dot watermarks that can be removed easily with a Photoshop filter.
~If its commercial... You could have a pay-wall, and steganographically embed the purchaser's name and or information into the image (or preview), such that if it does get used without permission, at least you know who did it.
Basicly: if your image is loaded by the Browser you can never protect the user to download it, because if the browser knows where to find the image, the user can find this out as well. So all this download protection only works for users not familiar with computers and the internet and nowadays i think most people are able to download such an image if they really want to.
If you want to prevent users to use your images for their work, you can use images with watermarks or in a lower resolution otherwise can you tell what reason do you have to prevent users from downloading?
I found this question in review of an HTML5 captcha alternative I'm developing. My goal is not to "prevent" users from downloading the image as much as blocking OCR on the image capture. To prevent it, I added a onclick event to the canvas object that resets the canvas element on click. The user can "download" it, but it no longer is the original code presented.
I keep running across this loading image
http://georgia.ubuntuforums.com/images/misc/lightbox_progress.gif
which seems to have entered into existence in the last 18 months. All of a sudden it is in every application and is on every web site. Not wanting to be left out is there somewhere I can get this logo, perhaps with a transparent background? Also where did it come from?
You can get many different AJAX loading animations in any colour you want here: ajaxload.info
I believe the animation came from the Mac OS X loading screen. Here's a similar one with a transparent background:
alt text http://homepage.mac.com/xraydoc/.Pictures/spinner.gif
I think it's just a general extension to the normal clock-face style loading icon. The Firefox throbber is the first example of that style that I remember coming across; the only real difference between that and the current trend of straight lines is that the constituent symbols have been stretched to give a crisper look, moving back to more of a many-handed clock emblem.