Change each pixels rgb values

Hi,

 

 

Thanks for the lead. I've encountered another issue. The error is INTERPRETATION_LIST has 1 entries , whereas the EXPRESSION_LIST has 546 entries.

 

What I tried to do is set the interpretation to auto, the I have my if statements all into the expression. e.g

 

@if (A[0] == 0, 3,3);

 

@if (A[0] == 1, 4,4);

 

@if (A[0] == 2, 5,5);

 

@if (A[0] == 3, 6,6);

 

@if (A[0] == 4, 7,7);

 

@if (A[0] == 5, 8,8);

 

@if (A[0] == 6, 9,9);

 

@if (A[0] == 7, 10,10);

 

@if (A[0] == 8, 11,11);

 

@if (A[0] == 9, 12,12);

 

 

Is there a way to multiline the expression?

 

Thanks.

Thanks again.

 

 

What i've tried was using an older raster expression evaluator that had the text box input for interpretations and was able to copy paste the correct number of matching interpretations to the expressions. i.e 546 interpretations, 546 evaluations.

 

The problem with that was, after processing every pixel contained 546 bands.

 

 

Just to describe what I have in further detail. The histogram matching has the source image and target image broken up into R,G,B and the percentage of occuring decimal values 0-255 across both images is calculated. Comparing these percentage values, I can determine, for example, when my target image has a Red8 value of 50, this is equivalent to source image Red8 30. So i've created a mapping of new RGB values for my target image. [30,50] 

 

 

So with the mapping I need to change the target image's rgb values according to the new mapping

 

 

[6, 7, 8, 9, 10, 11, 11, 12, 13, 13, 14, 14, 15, 16, 16, 17, 18, 18, 19, 20, 20, 21, 21, 22, 23, 23, 24, 24, 25, 25, 26, 26, 27, 27, 28, 29, 29, 30, 30, 31, 32, 32, 33, 34, 34, 35, 36, 37, 37, 38, 39, 40, 41, 42, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 66, 67, 68, 69, 70, 71, 71, 72, 73, 74, 75, 75, 76, 77, 77, 78, 79, 79, 80, 81, 81, 82, 83, 83, 84, 84, 85, 85, 86, 87, 87, 88, 88, 89, 89, 90, 91, 91, 92, 93, 93, 94, 95, 95, 96, 97, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 117, 118, 120, 121, 122, 123, 125, 126, 127, 128, 130, 133, 135, 136, 138, 140, 142, 144, 147, 148, 149, 151, 152, 152, 154, 156, 156, 157, 157, 158, 160, 161, 161, 161, 161, 162, 162, 162] 

 

 

The array above represents the mapping of a red channel. The index of the array would describe the decimal value. For example, Decimal 0 should be 6 instead. Decimal 1 should be 7.

 

 

Summary, I need a way to map new rgb values to a raster and write the new raster image out.

 

 

I'm now considering converting image to point cloud, change the red green blue component of the points, and then rasterize the point cloud.

I haven't thought of how the last value would be mapped. I might manual input the last value, so A[0] == 182, 162,162) , something along those lines. 

 

 

I'll give it a try. I have a python script to help me generate the entire expression statement which makes it easier.

 

 

 

Ok, so the nested expression works but I've now hit some type of limit with how many nestings it can support. I've reach about 130 nests, but it will not do the full 182 let alone 546, it simple says "error running translation" . I can work around this by dividing the script into two per channel, but ultimately costs me time. 

I've had a look for colormap but mostly lead to some of your own posts Gio. I need some pointers on the colourmap and what transformers I should be working with.

 

 

How do I reinsert a colourmap. Is this part of transforming into palettes instead of bands?

 

 

Thanks.

This is the data flow for testing.

 

That's great. I was able to upgrade my own skill about raster manipulations too :)