Canon In-Camera HDR Maps Single Exposure to Individual Pixels

Talk about changing the way HDR is done . . . .

A recently published Canon patent application (see USPTO Appl. No. 12/630,594) reveals a method for altering exposure values at the pixel level, which would allow Canon to produce a camera that captures a much wider dynamic range with a single image.

The lengthy patent application spells out a process whereby the camera captures a preliminary image with normal exposure values and then evaluates the exposure level across the entire image.  After creating an exposure map of the scene, the camera alters the exposure amount at the pixel level for the primary HDR image capture.

The present invention is directed to an image capturing apparatus and an image capturing method which are capable of appropriately expanding the dynamic range of an image sensor.

. . . .

According to an exemplary embodiment of the present invention, preliminary image capturing is performed using the image capturing unit, and the exposure time is assigned to each pixel based on the result of the preliminary image capturing. Image capturing can thus be performed with a wide dynamic range without a loss of highlight detail and a loss of shadow detail.  – USPTO Appl. No. 12/630,594, ¶¶ 11 & 14

The patent application also provides for designating exposure biased toward a specific region of the image, or to expose based on the relative luminance of a scene.  Exposure values can be manipulated up or down for each designation, which appears to mean that you would be able to dial in your own HDR style.

We’ve seen other cameras provide in-camera HDR modes that capture multiple images and then combine the images to create a higher dynamic range image.  The Sony A550 and A500 do this quite well.

Additionally, some cameras have attempted to create an HDR “look” by processing a single exposure in-camera with reduced contrast.  And, while this method can be successful to some extent in post-processing soft using RAW image files, the in-camera processed images tend to look overly “fake” or just plain bad.

Canon is reaching for some lofty goals by altering the exposure data on a pixel level.  If successfully implemented, this is one of those things that could change the way we use cameras forever.

Dynamic range is something that we try to squeeze as hard as we can at times.  However, “HDR” as a photographic art form has both lovers and haters.

Would you want to see this expanded dynamic range in your next camera?  How should the final camera work should Canon actually bring such one with this feature to market?


  1. Wally says

    I am a Zone System large format photographer. I would like to see dynamic range changed as desired by the artist in both highlight and shadow regions. The in system controls should be able to tell you, via matrix metering, how may stops difference exist in the scene and how may stops expansion or contraction you could render to suit personal taste. RGB to be dialed in individually per color. A dedicated Black and White mode or dedicated camera body is must. Post processing should allow for fine tuning if possible. Do this and I will sell my Nikon gear and become a Canon shooter.

  2. Wally Brooks says

    Following up on my earlier comment. Black and White as a option with full Manual control. Yes Engineer-San and Manager-San. Manual control. Simple concept, easy, do get it?

  3. Eric Calabros says

    history shows Canon is not good in Invention. they should let Nikon invent the Best and then copy and reproduce it in a Better way.

  4. Catastrophile says

    most of the time, we only hear about such patents in news items like this one, and then never hear or see anything about them again, it is becoming big time boring. :√(

  5. Eric is a M0r0n Noink fanboi says

    History shows Eric Calabros is dead wrong and is prolly a Noink fanb0i. Please do a little research on worldwide patent rankings yearly and compare Canon to Nikon. Canon is always #2 to IBM and Nikon is nowhere near the top 20.

  6. scott says

    Ugh, nevermind that last comment. I’ve been trying to track where this story stems from and I was looking at comment timestamps instead of the article. It would help if you explained where you came up with the news. (I guess in this case, let us know you were digging around on the USPTO website.) It’s hard to figure out where news originates these days.

  7. says

    Very interesting find!

    I hope they do the right thing and allow direct access to the HDR image. I don’t think we need another “picture style” magic in-camera tonemapping where all you get is the pre-processed JPEG that only has that “HDR look”. I want a real 32-bit file from the camera, call it the RAW HDR or Real HDR or whatever, that I can then tonemap in any style I desire. Or that I can use for lighting evaluation.
    BTW – I just put together a real HDR viewer, that illustrates the difference pretty well:

  8. says

    Fantastic news, I hope the results are as good or even better than regular HDR. I have a Canon 40D and a T1i and the day a new Canon comes out with this feature I am buying it. HDR photography give impressive results and is an incredible way of capturing light on a sensor, if Canon can make it easier to achieve the same results or better I am 100% for it !

    Go Canon, GO !


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