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New iPad Notes: Battery Charging at 100%, Safari Scaling Images

A couple of new findings as people spend more time with their new iPads. First, iLounge reports on findings by DisplayMate on the new iPads charging behavior. It turns out the iPad continues to charge for as long as an hour after it says its at 100%, suggesting the on-screen indicator isn't quite accurate and may still need more charging.
In an email exchange with iLounge, DisplayMate President Ray Soneira indicated that the third-generation iPad—when connected to power via the included Apple 10W Power Adapter—actually continued to draw 10W of power for up to one hour after reaching what is reported by iOS as a full 100% charge
iLounge found in their battery testing of the new iPad that sometimes the charge would drop initially quickly when they thought the iPad was fully charged.

Earlier in the week, Tom's Hardware noticed that Safari on the new iPad was automatically scaling large images down significantly.


Large images were automatically scaled down to near 1 megapixel resolutions. This means that if you are viewing large images through Safari, you aren't getting the full Retina experience. A workaround mentioned is to save the image to Photos which seems to preserve the original resolution.

These findings were confirmed by web developer Duncan Davidson who ran into the limit when trying to enhance his websites with Retina-sized images.

Top Rated Comments

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36 months ago
What's the point of the retina display if the images are just going to be scaled down? Didn't apple think about this before they released the iPad 3rd Generation?
Rating: 14 Votes
36 months ago
The Safari scaling issue is infuriating when looking for wallpapers. You simply can't look for them in your iPad because they're compressed to hell and scaled down to 1024x1024, you have to look for them on a computer, then transfer them to your iPad. I hope they fix this.
Rating: 9 Votes
36 months ago
What's the reason for the large images being scaled down? iOS bug?

EDIT: For those who say it is for memory, cellular reasons or speed of the web browser, the iPad 3 is meant for high resolution images. If there's one available, and you are on WiFi, then why restrain it. It does have 1GB of memory..

This makes sense on other iOS devices, but the iPad 3's selling point is the retina display. Seems daft to downscale images below the 3 megapixel screen the iPad 3 has when a WiFi connection is available along with enough memory.
Rating: 8 Votes
36 months ago

Probably Safari scales images on the server side (like an Apple proxy, as Opera does with its Opera Mini "turbo mode"). This may be one more agreement between Apple and carriers to keep low bandwidth usage.


No. Wifi content does not go through a proxy. This is built into the Safari app.
Rating: 6 Votes
36 months ago
Hi all,

I remember having trouble reading an online comic because some strips were bigger than 2Mega Pixels, the image was unsharp, as if the number of pixels was reduced to 1/4th (was confirmed on the ios Safari specifications doc)

is'nt it the same kind of behaviour ?

update: https://developer.apple.com/library/safari/#documentation/appleapplications/reference/safariwebcontent/CreatingContentforSafarioniPhone/CreatingContentforSafarioniPhone.html (https://developer.apple.com/library/safari/#documentation/appleapplications/reference/safariwebcontent/CreatingContentforSafarioniPhone/CreatingContentforSafarioniPhone.html)


Know iOS Resource Limits

Your webpage performing well on the desktop is no guarantee that it will perform well on iOS. Keep in mind that iOS uses EDGE (lower bandwidth, higher latency), 3G (higher bandwidth, higher latency), and Wi-Fi (higher bandwidth, lower latency) to connect to the Internet. Therefore, you need to minimize the size of your webpage. Including unused or unnecessary images, CSS, and JavaScript in your webpages adversely affects your site’s performance on iOS.

Because of the memory available on iOS, there are limits on the number of resources it can process:

The maximum size for decoded GIF, PNG, and TIFF images is 3 megapixels for devices with less than 256 MB RAM and 5 megapixels for devices with greater or equal than 256 MB RAM.

That is, ensure that width * height ≤ 3 * 1024 * 1024 for devices with less than 256 MB RAM. Note that the decoded size is far larger than the encoded size of an image.

The maximum decoded image size for JPEG is 32 megapixels using subsampling.

JPEG images can be up to 32 megapixels due to subsampling, which allows JPEG images to decode to a size that has one sixteenth the number of pixels. JPEG images larger than 2 megapixels are subsampled—that is, decoded to a reduced size. JPEG subsampling allows the user to view images from the latest digital cameras.

Rating: 5 Votes
36 months ago
The way it continues to charge after reaching 100% is normal for any brandnew device based on Li-Ion or Li-Po cells. The charge controller needs to get its bearings on exactly how much capacity it can stuff into each cell and the cell capacity tends to increase it bit over the first few cycles anyway.

It's constantly counting how much energy goes in and out and after a few cycles I would expect it to be much more accurate.
Rating: 4 Votes
36 months ago
This isn’t something new for the new iPad I don’t think.

I’ve long noticed that same down-scaling of big web photos on my iPad 2 and iPhone; I was never sure whether it was Safari or the web sites making the substitution, but now I’m thinking Safari.

If Photos can handle these sizes, then Safari should be able to as well. iOS 6?

(Re the battery meter: they always say to let the device fully drain occasionally, to keep the meter reading accurately. I never do because I just don’t care that much about a precise battery meter, only about the uptime delivered. But I wonder if that would reset the 100% mark correctly.)
Rating: 4 Votes
36 months ago

It is very clear that the battery issue should be investigated by the government and be made a big issue.

Why aren't the media especially NY Times and Consumer report not looking into this?

A consumer has the right to trust that when a device says 100% charged that it no longer draws additional electricity = cost behind the consumers back and without a consumers agreement.

We need a system preference panel pop up saying:

Battery almost full, but keep charging?
YES NO

Where is Senator Franken when we really need him?


are you drunk?
Rating: 3 Votes
36 months ago
Safari is scaling down large images for what should be fairly obvious: it has only 1GB of RAM. An 80 Megapixel image, regardless of whether it's a PNG, GIF or JPEG, decodes to the same size: 240MB (3 bytes per pixel, one each for the red, green, and blue channels).

That's almost a full 1/4 of all of the RAM on the iPad, for one picture! Of course, photo apps that don't downscale the image will necessarily use that much RAM to view it, but this can be allowed since you can generally trust the images already on your device.

Safari has to contend with image bombs. For example, using pixelmator, it is possible to create an 18250 x 18250 white (or other solid colored) image, which compresses down to a 1MB PNG file, yet decodes to nearly 1GB. If mobile safari naively decoded this image at it's full resolution from a malicious website, Safari, and possibly all of iOS would crash in a rather predictable manner, which may be able to be exploited to run arbitrary code.

In other words, down scaling images is a security measure! Now, Safari could be written to downscale the images less extremely on the iPad 3 (probably 5 Megapixel images would be okay), but it has to be done.
Rating: 3 Votes
36 months ago

Yes, and surprisingly enough web sites have background images which are specified using CSS, if you don't explicitly state the dimensions of the background image and it's over two megabytes, it's scaled down. Do learn to read.

This isn't a bug, it's about good web practice. Web sites are not "retina" experiences, they are optimised specifically for fast loading, low bandwidth and a fast user experience. If site developers wish to provide specific links to high resolution graphics, then they can do this - but these should not be used by default - imagine the load times on the average gallery site if each image was over two megabytes! It's simply good development practice.


Some websites are optimized for speed, but some are designed for aesthetics. The browser should not trump the intent of the website.

Besides, I bought a retina display, I want the retina experience.
Rating: 3 Votes

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