I just stumbled an article about a particular picture that if you set it as a wallpaper on your phone, will destroy it. At first i thought the code on the photo contained some kind of malware, but the truth is a lot more insidious. It all comes down to how the image is processed on your phone, we will explain the process that takes place, and why you should NOT set this picture as your wallpaper
BY: Rick
Image retrieved from: India Today
Most of us know that it is never a good idea to use files we don’t completely know and trust. A lot of malware and viruses disguise themselves as pictures and documents. One quick giveaway is in the extension; For example the file might appear as a JPG or PDF file, but if we look at the extension, we can clearly see it is an executable file, something like file.exe or file.msi. If you ever see a file that claims to be something other than an executable but has these extensions, DO NOT OPEN IT. It can run in the background and cause damage to your system. For Android phones, executable extensions can also be .jar, .aar, .apk, .so, .dex.
But what happens when the image is clearly a .jpg file and it still blocks out/destroys your phone?
How does it do it?
Mrwhosetheboss gave the best explanation in his Youtube channel, this is because of how phones handle images. There are different color profiles for computers and phones. In this case the profiles we need to know about are sRGB and ProPhotoRGB. Now here’s the thing. sRGB is the profile most devices use to keep display colors consistent, but the original picture was encoded in ProPhotoRGB. Which as a color range a tad wider than sRGB. It seems the photographer preferred the greater color range and brightness of ProPhotoRGB, which enhances his colorful gallery. Here is a link to Gaurav Agrawal’s gallery, the original photographer, again, we STRONGLY RECOMMEND THAT YOU DON’T SET THIS PHOTO AS A PHONE WALLPAPER. It is very likely your phone will get stuck in an error loop and you might have to factory wipe it
And the reason this happens is because of one pixel.
This particular pixel here:
Since ProPhotoRGB has a larger color range than sRGB, your phone is trying to interpret and convert the colors in that pixel from ProPhotoRGB to sRGB.
Mrwhosetheboss did the math. sRGB displays colors in Red Green Blue combinations, in scales from 0 to 255
And because green is the easiest color for our eyes to interpret for luminance, Android puts more weight in its color rendering formula, which in truth should give a value around 254.
However, Android’s interpretation tends to round up the values before combining them for display, giving it a number beyond the range, 256. And since the error is directly on the wallpaper program, the Android phone cannot completely close the program that runs the background, getting your phone stuck in a loop error.
So I installed the wallpaper and my phone is broken. How can I fix it.
People who have installed the wallpaper regardless of the warnings will most likely have to factory reset their phones. However there are a couple of things you can try.
- Extract the memory card that has the wallpaper saved and delete it using your PC
- If you can connect your phone to your PC and get it to display the internal memory, the usual paths for images saved for wallpaper are:
- /Android/data/
- /system/media/wallpaper
- /storage/emulated/0/Android/data/com.android.systemui/files/backupwallpapers/original_file_home.jpg and original_file_lock.jpg
- Root Required: /data/data/com.android.settings/files/wallpaper
Its pretty crazy that a single bug in a single pixel could destroy so many Android phones. It truly feels like a one in a million. But seeing the impact of the bug this particular image uncovered, it is safe to assume that the error will be patched in the next Android generations.
