Once again I come to the best for my pedestrian question.
I'm building a small web app that would be vastly improved by the ability to recognize app icons. I've searched all over but haven't found anything that suits my needs.
Basic Experience:
User uploads a screenshot
We extract icons
We return the name of the corresponding app
Here are a few points:
All icons will be grabbed from a screenshot.
All icons will be the same pixel width and height.
All icons will be grabbed from the same location in the screenshot.
All icons need to be matched against a library of icons (around 400 or so).
The app is built in rails so obviously anything with a ruby library is ideal, however, I'm willing to consider any alternate approaches.
Thanks in advance,
Harris
If the size and location of the icons will always be consistent, here's an idea: For each icon in your library of icons get the color of a few sample pixels, maybe 8 or 10 of them. Always the same 8-10 pixel locations. Store those in your database. When a user uploads their screenshot, take samples of the pixels at the same locations. Then search your database for colors that match in the same places. Since the colors might not be an exact match due to compression or other factors you'll need to include a "fudge factor." This shouldn't be too difficult to implement with ImageMagick or any imaging library that lets you grab a pixel color from an image.
Related
I'm tempted to provide the highest resolution icon and let iOS scale it down as necessary. Is this a bad idea, and (if so) why?
you'll definitely want to produce files of various sizes as required by xCode. You want to make sure that the file presented when the app runs is of a high quality.
There are tools out there that will automatically create all the sizes you need for your app icon. Here is a link to the site that I use: https://makeappicon.com/
Hope that helps!
Yes, it might be bad idea. If your icon art was produced using a vector image editor (e.g., Adobe Illustrator, Adobe Photoshop with vector primitives, Sketch, etc) you best bet is to export all required resolutions yourself. In doing so, you will guarantee the best possible output for each resolution.
Keep in mind that exporting a single high resolution image and then resizing, for each required resolution, using a bitmap editor (e.g., macOS Preview) won't produce the same results.
PS. As already pointed out, I'm not sure your binary will even be accepted by Apple if missing icon data :-(
I am into iOS development from past 1+ months and what I have experienced is that I have to put images for 1x 2x 3x for iphone and then 2x retina for ipad. One of the experienced designers has sugguested to me to go for svg format as it scales itself according to the screen sizes.
So my elaborated questions are:
Can I use svg instead of png?
Is it necessary to still put images in 2x and 3x for iphone and ipad if I'm using svg?
Will the images in svg scale according to the phone size and not lose quality?
If any other information according to your experience please share.
Thank you.
Official iOS Dev documentation says "the PNG format is the one most recommended for use in your apps". You can read it for a lot more information here.
Yes, although the supported file types table doesn't list it. Apple values user experience. SVG scaling consumes a few more CPU cycles which they don't like. PNG rendering is more efficient than SVG.
Yes, Apple explicitly recommends using multiple versions of the image at different sizes. Then scaling can be done from the file having the nearest dimensions.
Refer 1. There are cases like zoom-in / out scenarios where SVGs would be better though.
You could use vectorized PDFs alternatively. You can read more here. It isn't without limitations, but with vectorized PDFs, Xcode automatically generates scaled versions. That should make life easier. Note that sometimes the scaled results look quite poor.
I'm trying to set an icon for my app, however the icons derived from the original image are pixelated and look bad. I tried to provide the app icon gear application with images of different sizes, however the result is still unpleasant.
Should I provide it with images of higher resolution or lower resolution to get better results?
The answer to this question links to to a matrix provided by Apple for icon sizes. Should I use these sizes strictly, consider them as a lower border not to go under, or consider them as a ceiling not to exceed?
The docs states
Table 45-1 lists the sizes required for these custom icons and images.
Use the exact sizes.
Im programming an app in xcode and something has recently come to my attention when designing app icons. Here is the current setup that I have in my project:
Right now I have a 87x87pixel image for the "29pt" option (far left of the image), I also have a 120x120 for the 40pt option(middle) and I have a 180x180 pixel png for the 60pt option(far right). This seems highly inefficient, not only this but I need to supply #2 resolution images too? Surely there is a better way of doing this?
There are a couple of approaches I've taken in the past. One way is to create your icons, etc. in GIMP, Photoshop, etc. If you need to resize them, there's a command line utility called ImageMagick which I find to be a lot easier for resizing images than setting sizes in an image editor. The command you would use for resizing is called mogrify.
Option two is to get your hands on an app called Asset Catalog Generator. You just dump your images in and it spits out the correct file sizes and naming conventions. It's probably the best $4.99 I've spent in a long time.
Update
It appears someone has written a script to create the icons, too. I haven't used it myself, so you might want to poke around and look for others.
Create your app icon (once) at a decent resolution say 1024x1024. Drop the file into MakeAppIcon (a free service) and out pops all your icons in a zip file properly sized, enhanced as necessary, and rendered. Just drop them into images.xcassets and you're done. This avoids having to tweak any icons that may be off by a pixel or two and avoids those annoying Xcode warning messages.This vendor also offer a service for bulk uploading your iTunes screenshots, but I haven't tried that yet. Luv it!
You can use the vector-based images from a PDF. Session 411 from WWDC “What’s New in Interface Builder” discussed—albeit very briefly—Xcode’s support for creating your PNG files at build time from a vectorised PDF.
There is good article on this, you can refer that as well. http://martiancraft.com/blog/2014/09/vector-images-xcode6/
(Note that this does NOT cover PDFs for icons, just for images)
I would suggest you try SquareIcon, which I believe makes creating Xcode app icon sets very easy. Just to let you know, this is my own app.
The app allows you to drop in a generic image file (like a JPG or PNG) and convert it to a .appiconset file which you can put into your project's asset catalog. This takes care of all the naming and resizing that you might have to do manually.
UPDATE 2: I might've misunderstood you. When I wrote this answer, I thought that by 'inefficiency' you meant memory consumption and the resulting app size. If you meant, that making an icon for all the sizes is a lot of work, and you're looking for a better way to do it, consider looking at Adrian B's answer instead.
First of all, no, there is no more efficient way of doing it (unfortunately). Xcode supports vector images, but they are only supported on OS X, AFAIK. On iOS it just generates all necessary images at compile time.
Second, the app icon is small. You won't save a lot of space by optimizing app icon size. If you need to decrease the app size, try finding something that really takes much space. The icon doesn't.
UPDATE: Luckily, Apple realizes, that forcing everybody to download resources that they don't need is no good. So they introduced App Thinning along with iOS 9. I haven't looked into it thoroughly yet, but the general idea is that you upload a binary containing all the resources as usual, but when your users download the app from the AppStore, they get a version containing only resources that they need.
I am new to iOS programming and programming in general so this will probably be a fairly easy question to answer for someone who is experienced.
I am making a game using sprite kit and I need to include different background image sizes for the different retina display sizes on the iPhone 4 and 5. I am using a graphics package to create the images in .png format then adding them into the project, the issue I have is that, if I make a 640x1136 size image, it works on the 5, and if I use a 640x960, it works fine on the 4 but leaves blank space around the edge on the 5. (I am running it on the simulator)
If I include two identical images with different names, one for each device, how can I load the right one in? Do I only need high resolution image and can use some code to change how it loads the image in, so that it covers the whole screen without pixelation or loss of quality on both devices?
Any help or advice is appreciated. I apologise if this is a simple question, thanks for your time.
Note:
I found out plenty on the internet about using the #2x suffix for high resolution images, but that's not what I'm looking for. I know how to code for different resolutions, just not two different screen sizes with the same resolution, if that makes any sense.
If you're on iOS 7 SDK which you most likely are, make use of the .xcassets catalogue. It has options for different screen sizes, put the different versions of your image there. And then load image in code.