Data Recovery Case File · Cameras, Drones & Cards · When Half the Picture Is Grey

Corrupted SD Card Photos: When Half the Picture Is Grey

Her enquiry described the damage precisely without any technical vocabulary at all, which is the most useful kind of description. A microSD card in her phone: "when I look back at photos they are either completely grey and invisible, or partially blocked out. I am a total technophobe. The photos are obviously very precious and I would like to see if they can be recovered please." That pattern — some images entirely grey, others correct at the top and blank below — is not random damage, and it is genuinely informative. It tells us where in each file the trouble starts, which in turn tells us what happened to the card. This page explains it in plain terms, because she asked plainly: a photograph is read from the top down, and it goes grey at exactly the point the card stops giving good data. That has a hopeful consequence, which is the reason the recovery worked.

The decode: why photos go grey halfway, and what that leaves recoverable

How a photograph is read: a JPEG is not a grid of independent dots that can be read in any order. It is a compressed stream that must be decoded sequentially, from the top of the image downward, with each part depending on what came before. So when a viewer hits data it cannot read, it cannot skip ahead and carry on — it simply stops, and everything below that point is left blank or grey. That is exactly what she is seeing: a photograph that renders correctly for the top third and then greys out is a file whose data became unreadable a third of the way in. An image that is entirely grey is one where the failure occurs right at the beginning, before any of the picture could be decoded.

What that says about the card: the pattern points at read failures scattered across the card rather than a single catastrophic event. Some regions still return their data perfectly — hence the photographs that display in full — while others have become unreadable, and any image unlucky enough to have part of itself stored in one of those regions is truncated at that point. On a phone card this is a common ending: constant small writes, continuous power and warmth wear regions unevenly, and the first symptom owners notice is precisely this — pictures that have started coming back half-drawn.

Why that is more hopeful than it looks: two reasons, and they are the substance of the recovery. First, a sector that fails to read on one attempt does not always fail on the next — a drive or card struggling with a weak region will sometimes return good data on a repeated, patient read under proper timeout control, where a phone or a computer gives up instantly. Recovering those sectors restores the missing portions of the affected images. Second, and often more productive, phones and cameras leave earlier copies of images scattered through the card's unallocated space — previous versions, deleted duplicates, cached copies from when the picture was first written or shared. Those remnants frequently predate the damage, so an image that is half-grey in its current form may exist intact elsewhere on the same card. Carving for them is standard practice and it regularly returns complete photographs the visible library can only show as partial.

The one thing to stop doing: gently, because it is the natural response. Opening the affected photographs repeatedly to check whether they still look wrong makes each attempt another read on a struggling card, and the card is what everything else depends on. The pictures will not improve by being looked at, and the card gets a little older each time.

On the bench

The card was imaged write-blocked behind the DeepSpar USB Stabilizer 10Gb, with per-sector timeouts enforced so the pass could not stall on a struggling region — and the weak sectors that had been truncating her photographs were revisited on their own passes, patiently, where repeated reads recovered data a phone would never have waited for. On the completed image, the visible library was reconstructed and the truncated images repaired where the recovered sectors allowed; alongside it, OSForensics carved the unallocated space for earlier intact copies, which returned complete versions of a number of pictures that survived only as fragments in the current library. Every recovered image was then validated the only way that means anything for photographs — displayed at full size and looked at — before the set was delivered on fresh media.

The outcome

The photograph collection recovered by patient re-reading and by carving earlier intact copies, every image validated by rendering and delivered. Free assessment, one fixed written figure including VAT; on cards and sticks where content has been deleted or overwritten, the figure is payable upfront. The decode, in plain terms for anyone seeing the same thing: photographs decode from the top down, so an image goes grey at exactly the point the card stops returning good data, and a fully grey picture is one that failed at its very beginning; the pattern means scattered unreadable regions rather than a wholesale loss; weak sectors often give up their data on patient repeated reads that a phone will never attempt; and earlier intact copies of the same photographs frequently survive elsewhere on the card. Stop opening them to check, and let the card be read once, properly.

Our case files are drawn from genuine enquiries received by our laboratory over the past ten years, anonymised to protect client confidentiality. Each one describes the diagnostic and recovery procedure our engineers apply to that fault, using the equipment listed.