I'm using jpegtran to optimize images. However when I save a picture from Photoshop the size of the picture is smaller then if I save an image and optimize it with jpegtran on my server.
Other thing I don't understand is that if I check my site by "http://www.webpagetest.org" it reports that I can still compress these images, in some cases it reports the size can be reduced by 30-40%!
What am I doing wrong?
My optimize command is the following:
jpegtran -copy none -optimize -progressive -outfile
Thanks to #ceejayoz i guess the answer is that both photoshop and both the mentioned website uses lossy compression, which can be set with the -quality flag in jpegtran.
Related
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 am writing an iOS app which need to load a lot of full-screen size images into OpenGL. Image storage space is a concern, so I am using png or jpg. Problem is: Loading the image data takes way too long (100s of ms on an iPad2).
I was wondering if someone knows the fastest way to load good-quality compressed image data on an iPad or similar? This could include switching to different image compression formats (?)
Here's what I've found:
Loading jpg via the iOS implementation of libturbo-jpeg is faster than any way I found for png.
If you split jpg images in two, you can parallel-decompress via GCD which almost cuts the load time in half. Still not enough!
The PowerVR compressed PVRTC format can be loaded very quickly, but both compression ratio and image quality are way outside what I need...
No idea how jpeg-2000 would perform, but it seems to be optimized for compression ratio rather than decoding speed.
Any ideas?? This must be a common problem for games or similar..
Are there any newer image formats (jpg is 1986!!) which have portable implementation, maybe slightly less compression than jpg, but decode much faster?
This library might help you out:
https://github.com/path/FastImageCache
I realize that PNG is normally the web standard, but I might have a bit of a unique situation. I'm building an app that downloads lots of images from a server. The download needs to be as quick as possible, especially over 3G connections. I've been looking into the best compression for the images on the server. Ideally, every image I use can be quickly resized for the app using a drag and drop converter of some sort. When I convert one of the images to a PNG, the file size is around 130KB. When converted to an acceptable JPG quality however, the file size comes in at well under 50KB. Should I use JPGs in the application?
Thanks in advance,
It actually depends on the type of images.
The basic rule is to use JPEG for photos and PNG for everything else.
Why is it so?
JPEG compression is designed for photos - photos can handle lossy compression. On the other hand, PNG is compression designed for images which have similar pixels close to each other (straight lines, areas filled with one color, texts, etc.). If you try to use JPEG on an image which is not a photo, you'll be surprised - it won't look very good.
PNG is a standard - but for icons, backgrounds, patterns etc; not for photos.
Yes you can use jpg. You will not encounter any problem. It is a tradeoff between quality and size. Jpeg is usually smaller because it is compressed so as to reduce size. Png is lossless compressed.
I have made applications that use both png and jpeg and they both work like a charm.
EDIT: You can also check out this link PNG vs JPEG
PNG images are huge in size, use JPG as long as it's possible (when you don't need transparency)
I noticed that some article talking about crushed PNG images and how to uncrush them. What's the purpose of crush the images in the first hand? And also can the crushed images still be loaded using [UIImage imageWithName:]?
It's used to reduce the file's size, using lossless optimizations and/or compression.
It can evaluate your input image using several optimizations. Basic example: If your input is grayscale and saved as color, it may output a grayscale image. Of course, there are more complex optimizations which it uses.
can the crushed images still be loaded using [UIImage imageWithName:]?
Yes
It's basically a form of compression that doesn't involve any data loss (that is, you don't lose any image quality). Compressing any data reduces it's size that's the reason for actually doing it.
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.