Does the iOS 11 Apple AVCaptureMetadataOutput for scanning barcodes work with Code 128, Data Matrix, and QR Code when White on Black?
Any extra variables, properties, or settings in the library we are not familiar with?
There is a reasoning for this. The new iPhone 8 packaging is White on Black barcodes.
(we are aware this question has been asked before, however this is about iOS 11 and any new capabilities)
I think that what it tricks you into seeing as 'white lines' is the normal lighter coloured background. What you see as the 'black spaces between the lines', is the actual 'bars'.
So to replicate this, do not simply set your barcode artwork in white, that will not be machine-readable on ios11 or anywhere. Instead, you should maintain the original barcode & just crop it such that it appears to be white shapes on a black field.
Actually it isn't important to actually be black & white, we just need a distinct colour contrast to the scanning device, originally a red light laser. Make sure the black lines of the original design simply absorb more light and reflect less than the background colour between.
If you are trying to replicate this effect, make sure you have a bigger white block at the two extremes, and always test it on a few devices before rolling it out.
Related
I have a picture like the first one. I want to turn the colorful photo to black and white.So I want to turn all text and table to black and background to white. I used different method like local adaptive threshholding as you can see in the second image, or edge detection. But I am getting a poor result(The quality decrease radically). Do you know any filter which can do this and keep the quality high enough?
I'm working on a iOS application. My app icons has transparent background but when app installed on iPhone it shows white background.
Here is my app icon you can see the white borders:
How I can fit this icon?
You shouldn't have transparent background for app icons.
I suggest you to read the guidelines about icons. Explanation from these guidelines about transparency :
Avoid transparency. An app icon should be opaque. If the icon’s
boundaries are smaller than the recommended sizes—or you use
transparency to create “see-through” areas—the resulting icon can
appear to float on a dark background, which tends to look especially
unattractive on the beautiful wallpapers that users choose.
Pre-rendered icons on iOS
By default, iOS will modify the icon graphic you supply to add rounded corners, a drop shadow, and a reflective shine. The graphics here shows the before (left) and after (right) effects of this transformation. Apple recommends that your icon graphic have 90-degree corners, does not apply any shine or gloss, and does not use any alpha transparency.
You cannot prevent the rounded corners or drop shadow from being applied. But you can override the reflective shine by providing a "prerendered" icon and making a change in the tiapp.xml file. You might do so to apply your own shine effects. To prevent the default shine from being applied, update the following key in the tiapp.xml to have the value true.
<prerendered-icon>true</prerendered-icon>
Please read more from appc Doc http://docs.appcelerator.com/platform/latest/#!/guide/Icons_and_Splash_Screens-section-29004897_IconsandSplashScreens-Pre-renderediconsoniOS
That is expected. You can see this Apple Documentation that explains how you should design your icon to avoid this white background
For the icon sizes, please check the first row of this table.
I am interested how does iPhone built in photos app changes the clock's color when I previewing an image as a wallpaper. I have been searching for 2 days but no success. I understand that the method should analyze pixel's color behind the label. But going through each pixel seems to be inefficient. Could somebody guide me through this?
If you make a simple website with the code:
<div style='background-color: rgba(0,0,0,.05);width:50px;height:50px'></div>
and view it on various devices, you'll see very different colors.
On my iPhone and iPad, it looks white but on my MacBook you can see a definite light grey that looks close to #fafafa; I haven't tested thoroughly on other devices but I think that Android Chrome will sometimes display a third in between color.
This isn't an issue of different screen color capacities, because the iPad is definitely capable of displaying #fafafa.
So what's the story and is there any way to fix it?
rgba(0,0,0,.05) is an incredibly light color. A 5% tint is not visible on many lower end LCDs - especially 6bit panels. Personally, when I use RGBA I only tweak by 10% increments. Also, you will notice that #fafafa and rgba(0,0,0,.05) don't display the same because they aren't the same. #f2f2f2 is rgba(0,0,0,.05) (at least in Photoshop.)
You also have variances between the type of RGB. Devices also adapt differently based on lighting conditions - and they don't adapt the same way. There's also different screen types like AMOLED
From my experience that normally happens because of the contrast on the different screens and brightness settings. My suggestion is play with those.
Also check this for browser compatibility but those you mentioned should be ok:
http://css-tricks.com/rgba-browser-support/
(i can't post images so i posted links instead)
i'm working on a 2D platform game using pixelperfect.
The problem is about the png images used in-game. On transparency, there are some blur.
like this :
http://i.stack.imgur.com/lBX3A.jpg
If i open the texture with TheGimp, this is what i get :
http://i.stack.imgur.com/pOeF4.jpg
this is a sample of my map (zoom 1600x).
As you can see there is no blur around the black. (the grey squares means transparency).
Tests i did :
save without compression and re-opened it = no blur.
to be sure, i added a white background in gimp (it's easier to see the dark blur on white) :
(http://) i.stack.imgur.com/jfhWv.jpg
of course, i removed the white background because i wanted it transparency.
last information : there is blur on every transparency png images, even on my spritesheet character. When i animate it, i can see the blur from others frames.
After my tests, i concluded that gimp isn't the problem.
Can you help me ? Thx for reading.
xna4, c#2010 express edition, gimp2.611.
Sorry about my english ^^
This happens because of "texture filtering", which xna does by default.
You probaly can disable this.
found something: https://gamedev.stackexchange.com/questions/6820/how-do-i-disable-texture-filtering-for-sprite-scaling-in-xna-4-0