a martian oddbox

[funbox]

so why does it look like a circle and a triangle at 100 % , no zooming or resampling, as appears in your exploded version no cheating ArMaP

or can you not see them at 100% ?

funbox

[ArMaP]

so why does it look like a circle and a triangle at 100 % , no zooming or resampling, as appears in your exploded version no cheating ArMaP

Because of the way JPEG works.

[funbox]

Because of the way JPEG works.

explain again ? I think we've gone full circle , but it still doesn't explain , if they were artefacts created say a seam of calcite, they are big enough to see at 100% , they go circular and triangular when zoomed say to 400 %. in your estimation how far would you say that rock was away?

funbox

[ArMaP]

The biggest problem with JPEG compression is that it changes the image to achieve a higher compression ratio.

Yesterday I created this image to try to show what I mean.



I used the same 7 pixels wide circle (it's supposed to be a circle, but the algorithm used by Paintshop Pro is not the best for small sizes, as you can see) but I put it in different places in regards to the 8x8 blocks the JPEG compression uses, as you can see below.



Then I saved the image as a JPEG with a high compression and, to avoid creating more artefacts, resaved it as a PNG, and this is the result.



As you can see, the JPEG compression not only changed all the circles in a way that we don't have two that look the same it also created darker or brighter areas in some places, creating an image that has many differences when compared with the original.

To help see how the 8x8 blocks are responsible for the changes here's an animation to show where the blocks are located.



PS: I wasn't able to create a triangle, but I hope you can see why I don't trust small features on a highly compressed JPEG image.

[funbox]

you missed something

the other half of the example should have shown what happens to a perfect circle and a triangle under identical compression ratio as your exampled

I would do this , but unfortunately there's been a gif juice, reality extraction. the wolves cannot get there

funbox

[funbox]

is this a shadow , or a darkened patch of something ? *obfuscation* from Sol 1144, the new set from mast cam




http://mars.jpl.nasa.gov/msl-raw-images/msss/01144/mcam/1144ML0051850900501577E01_DXXX.jpg

maybe something the rover left  over, it looks like it been crunching stuff up in this region

funbox

[zorgon]

Looks like a piece of rock standing and casting a shadow...

[rdunk]

Looks like a piece of rock standing and casting a shadow...

+1

[funbox]

Looks like a piece of rock standing and casting a shadow...

how so then, does the shadow extend all the way around this piece, two suns? , or is it sitting in a ditch/ divot ? are you sure its not a darker material? . there does not seem enough definition here to be just a mere Rock


@rdunk plus what ? a darker obscuring material ?

funbox

[ArMaP]

I see a shadow and a darker area under the rock.

Why don't you make an animated GIF to show what you mean, are you out of GIF juice?

[rdunk]

@rdunk plus what ? a darker obscuring material ?

funbox
..............................................................

Hey funbox - +1 on forums usually means "I agree" - with Zorgon in this case, as I thought it looked like a rock too.

But now, after looking at it more, this small feature does look a little odd. Also, if that is supposed to be a shadow on the flat surface, it seems to bear no resemblance to the outlines of the feature. I have magnified it even more, and there are some odd looking features we can see - at least 3 features that are cylindrical shaped with each having  a hole in its center. And these are there, even when we demagnify, but are just much harder to see with no mag.

Yes, with the shadowing, it has the appearance of a rock, but then the magnified detail looks otherwise?? Here is my slightly different magnification of your image.

[funbox]

I see a shadow and a darker area under the rock.

Why don't you make an animated GIF to show what you mean, are you out of GIF juice?

unfortunately something bad happened to the Gargantuan pack of wolves , last seen heading past the sun



gif juice maybe problematic

*small yet frenetic incursions ripple and squarate into places deep past, violent portal's erupt into smaller calmer versions, slowly lulling droplets of the precious gif juice ever closer into acutance*

funbox

[funbox]

@rdunk plus what ? a darker obscuring material ?

funbox
..............................................................

Hey funbox - +1 on forums usually means "I agree" - with Zorgon in this case, as I thought it looked like a rock too.

But now, after looking at it more, this small feature does look a little odd. Also, if that is supposed to be a shadow on the flat surface, it seems to bear no resemblance to the outlines of the feature. I have magnified it even more, and there are some odd looking features we can see - at least 3 features that are cylindrical shaped with each having  a hole in its center. And these are there, even when we demagnify, but are just much harder to see with no mag.

Yes, with the shadowing, it has the appearance of a rock, but then the magnified detail looks otherwise?? Here is my slightly different magnification of your image.

ahh you got  your eyes right in there great stuff , kinda reminded me of Arkens flower/bulb thing .. tis always in the shadows, as Mario could testify , if he was here

funbox

[funbox]

so Martians like to store there coffee outdoors eh ... nice



http://mars.nasa.gov/msl/multimedia/raw/?s=1179&camera=NAV%5FLEFT%5F

sits with me, like a belly fuill of coffee

funbox

[ArMaP]

I don't have the slightest idea of what you're talking about.