a$.$ Initial HDR Implementation

This exercise is the initial implementation of HDR images, as below. You will find on folder a set of photos $($from $00.$CR$3$ to $10.$CR$3).$ For each of them, the exposure time was half the one of the previous photo.

Combine them to produce HDR raw data. Then, apply the demosaicing algorithm and the white balance. Decrease the dynamic range by computing the logarithm of this data, and downscale it to the $[0,255]$ interval. Then save the resulting image.

You should obtain the same result as what is shown in the slides.

Simple combination approach:

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Load brightest raw data $($longest exposure$)$

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Let$$s call it h

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For each next raw file:

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Load it and name it i

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Multiply i by the exposure difference to the first photo

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E$.$g$.,$ first photo $1$s$,$ second photo $0\mathrm{.}5$s$,$ multiply by $2$

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Values in h which are above a threshold t get replaced by the corresponding values in i

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t is not that important

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Avoid the $$plateau$$ in i

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A value of $0\mathrm{.}8$max$($h$)$ should be fine

b$.$ iCAM$06$

Implement the iCAM$06$ HDR method, a iCAM$06$ aims at preserving details, without halo effect, and compresses more the $$base$$ of the image:

Pseudocode:

output$\_$range $=4$

input$\_$intensity $=1/61(20$red $+40$green $+$ blue$)$r$,$ g$,$ b $=$ rgb $/$ input$\_$intensity

log$\_$base $=$ bilat$\_$filt$($log$($input$\_$intensity$))$

log$\_$details $=$ log$($input$\_$intensity$)-$ log$\_$base

compression $=$ log$($output$\_$range$)/($max$($log$\_$base$)-$min$($log$\_$base$))$log$\_$offset $=-$max$($log$\_$base$)$ compressionoutput$\_$intensity $=$ exp$($log$\_$base $$ compression $+$ log$\_$offset $+$ log$\_$detail$)$rgb $=$ r$$output$\_$intensity, g$$output$\_$intensity, b$$output$\_$intensity. Try different settings to find the ones you like the best.

Hint: bilateral filters are slow, so while developing your solution, use at first very small kernels to minimize the run time.

c$.$ Win

$..$ or at least try to$!$

Implement a demosaicing function named process raw which takes two parameters:

$1.$ The path to a raw file $($CR$3$ format$)$

$2.$ The path to wich the resulting JPG image has to be saved

Hint: you will be judged based on the quality of your

Provide python code without using CV$2$ for a$,$ b $,$ c