Thread overview | |||||||
---|---|---|---|---|---|---|---|
|
February 21, 2021 Problem Computing Dot Product with mir | ||||
---|---|---|---|---|
| ||||
I am trying to convert sRGB pixel values to XYZ with mir using the following guide: http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html My problem is that I cannot figure out how to calculate a dot product using mir. Here is my code: import std.stdio; import mir.glas.l1 : dot; import mir.ndslice; void main() { auto rgbToXyz = [0.4124564, 0.3575761, 0.1804375, 0.2126729, 0.7151522, 0.0721750, 0.0193339, 0.1191920, 0.9503041] .as!double .sliced(3, 3); alias reduceDot = reduce!"a * b"; auto pixels = [255, 0, 0, 0, 255, 0, 0, 0, 255, 120, 120, 120] // convert input array elements to double - lazy .as!double // create a slice-shell over the input array .sliced(2, 2, 3) // normalize to range [0, 1] .map!(p => p / 255.0) // sRGB inverse compand .map!(V => V <= 0.04045 ? V / 12.92 : ((V + 0.055) / 1.055) ^^ 2.4) // linear RGB to XYZ // iterator over pixel values - 3rd dimension .pack!1 // dot product of pixel value with conversion matrix .map!(a => reduceDot(rgbToXyz, a)); //.map!(a => dot(rgbToXyz, a)); writeln(pixels); writeln(pixels.shape); } In the last step I am trying to take each pixel value from my 2x2 'image' and compute a dot product of it and the conversion matrix rgbToXyz. I have tried reduce and that results in: Error: cannot implicitly convert expression nonInlinedNaryFun(seed, ls()) of type Slice!(VmapIterator!(double*, LeftOp!("*", double)), 2LU, cast(mir_slice_kind)2) to Slice!(double*, 2LU, cast(mir_slice_kind)2) I have also tried dot from mir.glas.l1: Error: template mir.glas.l1.dot cannot deduce function from argument types !()(Slice!(double*, 2LU, cast(mir_slice_kind)2), Slice!(MapIterator!(int*, pipe), 1LU, cast(mir_slice_kind)2)) I was expecting the conversion matrix (3x3) dotted with the pixel (3x1) to produce another pixel (3x1). What am I doing wrong here? |
February 22, 2021 Re: Problem Computing Dot Product with mir | ||||
---|---|---|---|---|
| ||||
Posted in reply to Kyle Ingraham | On Sunday, 21 February 2021 at 16:18:05 UTC, Kyle Ingraham wrote:
> I am trying to convert sRGB pixel values to XYZ with mir using the following guide: http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html
>
> [...]
mir-glas is deprecated experimental project. It is worth use mir-blas or lubeck instead. There is also naming issue. In the classic BLAS naming dot refers a function that accept two 1D vectors.
|
February 23, 2021 Re: Problem Computing Dot Product with mir | ||||
---|---|---|---|---|
| ||||
Posted in reply to 9il | On Monday, 22 February 2021 at 07:14:26 UTC, 9il wrote:
> On Sunday, 21 February 2021 at 16:18:05 UTC, Kyle Ingraham wrote:
>> I am trying to convert sRGB pixel values to XYZ with mir using the following guide: http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html
>>
>> [...]
>
> mir-glas is deprecated experimental project. It is worth use mir-blas or lubeck instead. There is also naming issue. In the classic BLAS naming dot refers a function that accept two 1D vectors.
Your suggestion worked beautifully. I went with lubeck. I don't know how I missed it seeing that it is right there in the Dlang tour.
Thank you for writing such useful libraries.
Final code ended up being:
import std.stdio;
import kaleidic.lubeck: mtimes;
import mir.ndslice: as, byDim, fuse, map, sliced;
void main()
{
auto rgbToXyz = [0.4124564, 0.3575761, 0.1804375,
0.2126729, 0.7151522, 0.0721750,
0.0193339, 0.1191920, 0.9503041]
.as!double
.sliced(3, 3);
ubyte[] rgbPixels = [255, 0, 0,
0, 255, 0,
0, 0, 255,
120, 120, 120];
auto xyzPixels = rgbPixels
// convert input array elements to double - lazy
.as!double
// create a slice-shell over the input array
.sliced(2, 2, 3)
// normalize pixel channels to range [0, 1]
.map!(chnl => chnl / 255.0)
// sRGB inverse compand
.map!(chnl => chnl <= 0.04045 ? chnl / 12.92 : ((chnl + 0.055) / 1.055) ^^ 2.4)
// linear RGB to XYZ
// iterator by x and y over pixels (3rd dimension)
.byDim!(0, 1) // same as .pack!1
// dot product of each pixel with conversion matrix
.map!(pixel => mtimes(rgbToXyz, pixel))
// join iterator values into a matrix
.fuse;
xyzPixels.writeln;
xyzPixels.shape.writeln;
}
|
February 23, 2021 Re: Problem Computing Dot Product with mir | ||||
---|---|---|---|---|
| ||||
Posted in reply to 9il | On Monday, 22 February 2021 at 07:14:26 UTC, 9il wrote:
> On Sunday, 21 February 2021 at 16:18:05 UTC, Kyle Ingraham wrote:
>> I am trying to convert sRGB pixel values to XYZ with mir using the following guide: http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html
>>
>> [...]
>
> mir-glas is deprecated experimental project. It is worth use mir-blas or lubeck instead. There is also naming issue. In the classic BLAS naming dot refers a function that accept two 1D vectors.
Deprecated as in formally dead or postponed?
|
February 23, 2021 Re: Problem Computing Dot Product with mir | ||||
---|---|---|---|---|
| ||||
Posted in reply to Max Haughton | On Tuesday, 23 February 2021 at 03:48:15 UTC, Max Haughton wrote:
> On Monday, 22 February 2021 at 07:14:26 UTC, 9il wrote:
>> On Sunday, 21 February 2021 at 16:18:05 UTC, Kyle Ingraham wrote:
>>> I am trying to convert sRGB pixel values to XYZ with mir using the following guide: http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html
>>>
>>> [...]
>>
>> mir-glas is deprecated experimental project. It is worth use mir-blas or lubeck instead. There is also naming issue. In the classic BLAS naming dot refers a function that accept two 1D vectors.
>
> Deprecated as in formally dead or postponed?
Postponed until someone wish to invest in BLAS library in D.
|
Copyright © 1999-2021 by the D Language Foundation