MSL Images & Cameras, technical discussions of images, image processing and cameras |
MSL Images & Cameras, technical discussions of images, image processing and cameras |
Aug 16 2012, 11:05 PM
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Senior Member Group: Members Posts: 2228 Joined: 1-December 04 From: Marble Falls, Texas, USA Member No.: 116 |
I'm still trying to figure out a number of things about the new images we are trying to work with. Assuming others are likewise trying to learn, I thought I would open this thread to create a place for such discussions.
I'd like to start out with a comment about raw image contrast. There have been several postings in the main threads about whether or not the MSL raw images have been stretched like those from the MER missions. I am certainly no expert on this, but it looks to me as if the MSL images have not been stretched at all. I haven't tried to analyze all of the image types, but the hazcams and navcams have pixel brightness histograms that are very different from their MER counterparts. This attached image compares MER and MSL navcams along with their luminosity histograms. The MSL images clearly are not using the entire, available range of brightness values, whereas the MER raws do. For this reason, the MSL raw images can usually be nicely enhanced by simply stretching the distribution of brightness across the full 256 value range. -------------------- ...Tom
I'm not a Space Fan, I'm a Space Exploration Enthusiast. |
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Oct 10 2012, 07:05 PM
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Member Group: Members Posts: 154 Joined: 19-September 12 Member No.: 6658 |
I did made some tests but the false colored (using only red, green and blue filters, no IR) just look like the color images with auto-whitebalance or auto-color-correction (left). With balancing out the single channels I come pretty close to the color images (greys slightly too blue - right). I did not see anything fancy in the infrared ones yet.
Bayer color image. This image gives some hints. For "true" color I get better results with the "nearIR-Red" (left). With the "650-nm-red" the blue edge on the "sundial" turns red/pink like on the MER pancam (right) - no idea why it is this way. Sometimes the filtered shots are not 100% aligned. Often the first shot is green, second is blue, third is 650 nm, fourth is 750 nm, then IRs - but double-check with the thumbnails to be safe. I do use this numbers for R-G-B: R 240/30/0 - G 55/255/0 - B 255/0/0. So #5 for me |
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