The landing page for an ipad retina (i.e 1536 x 2048) is about 2MB. Apple seems to mandate using a PNG for landing pages. Is it possible to reduce this file size? (my landing page is really simple already)
actually the byte size of image not only depends upon the resolution but also on bit depth.
e.g. 100x100 PNG 16bit/24bit
you can reduce the bit depth of the png if you feel like it is not affecting the image quality and if you do find the image quality becomes unacceptable on reducing bit depth then your image is not that simple.
you can also use colors/gradient instead of an image so that you can completely remove the image
you can also use the tiled image (if it suits you) and can keep a small image in the resources.
see... you have lots of choices my friend..!!
I am using ImageOptim to reduce all my images. Works great and fast. Just download, open and drag and drop a folder or all your images onto the interface.
http://imageoptim.com/
There is even a case study on how well this tool can be used to shrink your iOS-Apps:
http://imageoptim.com/tweetbot.html
Use Image Optimiser. You can optimise image online.
Related
The images I am getting back from the photo library and camera are HUGE, and it takes a significant amount of time to send them over the network even in good conditions. I can't imagine a scenario in which I would need the full double-digit MB image, but maybe I'm missing something? Is it common practice to resize them before sending them over the network?
Yes it is common practice to alter an image's dimensions and compression so that it is appropriate for application.
As observed, by the default images from the camera are very large so that they can be displayed on large screens, printed to posters, zoomed and cropped etc without appearing unduly pixelated. So unless the app in question is a photo/image manipulating app, then resizing will almost certainly be beneficial in that it can improve networking, the app's memory foot-print and it's overall snappiness.
In terms of how to size and compress, while it is possible to store multiple versions of the image for each device that's being supported.
Practically, it seems that storing a single image at the dimensions required on the lowest resolution device but then only compressing it enough so that the higher resolution devices can scale up as needed without looking ugly seems to deliver reasonable results.
In terms of resizing, there are various posts on SO e.g. How do I resize the UIImage to reduce upload image size
I've also stuck gist for the UIImage extension I'm currently using to do this in my App over on GitHub here.
Have fun.
You can transform the image into data and then use this:
let imageData = image!.jpegData(compressionQuality: 0.5)!
It will make the quality less than usual with 50% to be able to save it quickly and smoothly
Are there any web tricks to speed up the loading of a web page. I have a few pages where I have images which were created in photoshop, but they are saved as a PNG. The load time is fairly slow of the page due to this, is there anyway to speed up a page load? They are in the region of 1.2/1.5MB
Reducing the size of the file would be a significant advantage.
Additionally converting the asset to webp for Chrome and Firefox, jp2 for Safari and falling back to png would help retain quality while reducing file size.
If the image isn’t in the first viewport you can also try lazy loading the image with something like lazysizes or at the very least the loading attribute.
You could compress the images using an online tool. Although, this may slightly reduce the quality.
I’ve used this site before: https://tinypng.com/
Other than that, I’m not sure if you can “speed up” the load time for a webpage.
You can check your website images here
https://www.imghaste.com/pagespeed/
1.2 to 1.5MB for each image is way large.
You need to adopt a process where you can optimize/shrink images for your website.
If you don't really need the images to be PNG you can always convert them to JPEG.
https://www.imghaste.com/converter
I am new with cocs2d. I have created an app using Cocos2d. The app is working fine but problem is that application size is too large 350MB. There are many images in this app. I have used png and where possible jpeg images. There are many png images that have larger than 1 mb.
Is there any way to reduce the application size. I've reduced the size whereever possible. Is there any other format that can be used in place of png? There are no many animations. The png are used only purpose of transparency.
Your images are way out of size. Even if you put them on server, and then download it will take time to download.
The best option is to reduce the image size. A couple of sites that can help you do that are:-
Reduce image size
Compress image size
You can keep the image content on your server and then download the image content asynchronously (which is more imp download it first). If there are levels then download initial levels first and download remaining on the background thread. You can always display a loader on launch and display some help kinda stuff meanwhile the data gets download and cached.
You can make use of SDWebImage and other libraries to get your images stuff async.
Hope it helps.
While your pictures are fairly large and you should try to reduce the number and size, you can make gains through packaging the .png into pvr.ccz files. There are multiple different programs available to do this. I like to use Texture Packer which is available here: http://www.codeandweb.com/texturepacker
You can find some tips in my post on reducing memory usage & bundle size.
Most importantly use texture atlases in .pvr.ccz format and where possible reduce image color depth to 16 bit. Avoid JPGs altogether because they're terribly slow to load in cocos2d.
There is no issue in using png files although your images are too large, You can reduce their size by 70 - 80% by using tinypng and it will not going to hurt your graphics.
https://tinypng.com/
I usually edit the image size now https://resizeimage.io , you try!
I'm making a Universal App using MonoTouch, and I'm adding my Default-Portrait.png file. That file alone (a 768x1004 .png file) is adding 711k to the size of the app. My app itself is only about 7 megs, so it's adding 10% just for the splash screen.
I could easily make this thing an 80k jpg file instead of a png, but the device doesn't seem to look for a .jpg file. Does anyone have tips for reducing the size of this launch art?
At this point, I'm thinking I might just leave the launch art out and load my own jpg and display it as soon as I have the ability to. That'll keep my app size down, but it's not as nice as having the launch art scale in immediately like most apps do.
Hmmm...given the screen of the iPad and the visual quality users are expecting, I'd just leave it like that.
But if you do want to reduce the disk space, try going to Project > Edit Project Settings > Build (tab at top), and searching for a parameter called "Compress PNG Files." Make sure that's checked. It'll run the pngcrush utility before loading the file onto disk (check the size of your IPA archive after to see if it had any effect).
pngcrush is nice as well, however that will not reduce the quality of you image. If reducing the quality of the image is an option for you, then you might try this tool: http://www.punypng.com/ - or just use an image editing tool to "optimize" the image ...
I recommend pngout if you want to really squeeze those PNGs down, and this won't cost you any quality. It simply removes unnecessary metadata (like pngcrush) and uses its own compression algorithm which is compatible with the regular decompressor used in PNG (zlib). It's really slow, though.
A simpler option is to try "Save for web" in your image manipulation program of choice. Exporting from Acorn (not just the regular save) sometimes gives me vastly smaller files. This is especially true for default images which have large, uniform areas in one colour (screenshots, a small logo in the middle of a black screen).
Is there any reason why you want to reduce the file size that badly? I don't think it matters in your case. I just checked 3 of my apps and the Default.png (of various portrait/landscape varieties) is between 29KB and 422KB, so whilst yours do seem a little heavy, your still way under the 3G download limit.
Are you positive it's adding that much to the size of the app? Did you compare a before and after?
Xcode uses pngcrush on the images for you. I know because I just tried to substitue jpegs for pngs and got the following result:
So, in short, there's not a lot to be done except simplify the image beforehand. Xcode will handle the rest.
I have an app that will display a bunch of images in a slideshow. Those images will be part of the bundle, thus distributed with the app.
All the images are photographs or photographic, etc.
I've read that it's preferred to use PNG as the image format, but seeing that the JPG version will be much smaller, I'd rather be using that.
Are there any guidelines which format to use and in which case?
PNG's are pixel perfect (non-lossy), and require very little extra CPU energy to display. However, large PNGs may take longer to read from storage than more compressed image formats, and thus be slower to display.
JPG's are smaller to store, but lossy (amount depends on compression level), and to display them requires a much more complicated decoding algorithm. But the typical compression and image quality is usually quite sufficient for photos.
Use JPG's for photos and for anything large, and PNG's for anything small and/or designed to be displayed "pixel perfect" (e.g. small icons) or as a part of a composited transparent overlay, etc.
Apple optimizes PNG images that are included in your iPhone app bundle. In fact, the iPhone uses a special encoding in which the color bytes are optimized for the hardware. XCode handles this special encoding for you when you build your project. So, you do see additional benefits to using PNG's on an iPhone other than their size consideration. For this reason it is definitely recommended to use PNG's for any images that appear as part of the interface (in a table view, labels, etc).
As for displaying a full screen image such as a photograph you may still reap benefits with PNG's since they are non-lossy and the visual quality should be better than a JPG not to mention resource usage with decoding the image. You may need to decrease the quality of your JPG's in order to see a real benefit in file size but then you are displaying non-optimal images.
File size is certainly a factor but there are other considerations at play as well when choosing an image format.
There is one important thing to think about with PNGs. If a PNG is included in your Xcode build it will be optimized for iOS. This is called PNG crush. If your PNG is downloaded at run time it will not be crushed. Crushed PNGs run about the same as 100% JPGs. Lower quality JPGs run better than higher quality JPGs. So from a performance standpoint from fastest to slowest it would go low quality JPG, high quality JPG, PNG Crushed, PNG.
If you need to download PNGs you should consider crushing the PNGs on the server before the download.
http://www.cocoanetics.com/2011/10/avoiding-image-decompression-sickness/
The Cocoanetics blog published a nice iOS performance benchmark of JPGs at various quality levels, and PNGs, with and without crushing.
From his conclusion:
If you absolutely need an alpha channel or have to go with PNGs then
it is advisable to install the pngcrush tool on your web server and
have it process all your PNGs. In almost all other cases high quality
JPEGs combine smaller file sizes (i.e. faster transmission) with
faster compression and rendering.
It turns out that PNGs are great for small images that you would use
for UI elements, but they are not reasonable to use for any full
screen applications like catalogues or magazines. There you would want
to choose a compression quality between 60 and 80% depending on your
source material.
In terms of getting it all to display you will want to hang onto
UIImage instances from which you have drawn once because those have a
cached uncompressed version of the file in them. And where you don’t
the visual pause for a large image to appear on screen you will have
to force decompression for a couple of images in advance. But bear in
mind that these will take large amounts of RAM and if you are
overdoing it that might cause your app to be terminated. NSCache is a
great place to place frequently used images because this automatically
takes care of evicting the images when RAM becomes scarce.
It is unfortunate that we don’t have any way to know whether or not an
image still needs decompressing or not. Also an image might have
evicted the uncompressed version without informing us as to this
effect. That might be a good Radar to raise at Apple’s bug reporting
site. But fortunately accessing the image as shown above takes no time
if the image is already decompressed. So you could just do that not
only “just in time” but also “just in case”.
Just thought I'd share a bit of decompression performance data...
I'm doing some prototyping of a 360 degree viewer - a carousel where the user can spin through a series of photos taken from different angles, to give the impression of being able to smoothly rotate an object.
I have loaded the image data into an array of NSData's to take file i/o out of the equation, but create NSImage's on the fly. Testing at near max frame rate (~25 fps) and watching in Instruments I see the app is clearly CPU-bound and there's an approximately 10% increase in CPU load showing ~275 kb png's vs. ~75 kb jpg's.
I can't say for sure but my guess is the CPU limit is just from general program execution and moving all the data around in memory, but that image decompression is done on the GPU. Either way and the JPG vs. PNG performance argument looks to favour JPG, especially when the smaller file sizes (and therefore smaller sizes of objects in memory at least in some parts of the chain) is taken into consideration.
Of course every situation is different, there's no substitute for testing...
I have found massive differences in animation performance when using jpegs vs png. For example placing three screen-sized jpegs side by side in a UIScrollView and scrolling horizontally on an iPhone4 results in lag and a thoroughly unpleasant jerky animation. With non-transparent pngs of the same dimensions the scrolling is smooth. I never use jpegs, even if the image is large.
I think if you want to use transparent, you have no choice except PNG. But, if your background is opaque already, then you may use JPG. That is the only difference I can see
'Use JPEG for photos' as mentioned in Human Interface Guidelines under section Produce artwork in the appropriate format.