I have an image that I import into Octave 5.2, and I would like to create an outline all the way around the image array using RGB values.
I'm having trouble inserting the RGB values back into the array correctly, inserting / generating the two rows at top, two columns on the left, two columns on the right, and two rows on the bottom all the way around the image / converted double array.
Example of original image:
Example of the image I'm trying to get when done:
My logic was:
To convert the image to a double array so I can do math / insert the RGB values where I wanted them.
Insert the RGB values into the left, right, top, bottom of the array.
Convert the double array back to uint8 to export / view it as image.
My code so far:
pkg load image
img_fn=('https://i.imgur.com/KKxJaOy.png'); %original image
f=imread(img_fn);
[im_r im_c]=size(f);
size_min=min(im_r,im_c); %get minum size from row and col
f_double=double(f); %need to convert to double to do math functions on it
outline_left_of_box=repmat(255,[rows(f_double),2]); %Create left line array of outline red box
f_double_tmp_red(:,:,1)=[outline_left_of_box,f_double];%Create left line of outline red box
red_outline_right_of_box=repmat(255,[rows(f_double),2]); %Create right line array of outline red box
red_outline_top_of_box=repmat(255,[2,columns(f_double)]); %Create top line array of outline red box
red_outline_bottom_of_box=repmat(255,[2,columns(f_double)]); %Create bottom line array of outline red box
%convert back to image
red_outline_img=uint8(f_double);
imshow(red_outline_img); %used to show image in octave plot window
Please note: I'm converting the image array into a double because calculations will be done on the array to get the desired color box around the image, but I'm just trying to get the inserting RGB values into the array issue fixed first.
Maybe it's easier to simply paste the inner part of the input image onto some "background" image with the desired border color, like so:
pkg load image
% Read image, get dimensions, convert to double
f = imread('https://i.imgur.com/KKxJaOy.png');
[im_ro, im_co, im_ch] = size(f);
f_double = double(f);
% Set up width and color of border
bw = 2;
color = ones(1, 1, im_ch);
color(1, 1, :) = [255, 0, 0];
% Create image of same size as input with solid color, and paste inner part of input
red_outline_img = ones(im_ro, im_co, im_ch) .* color;
red_outline_img(bw+1:end-bw, bw+1:end-bw, :) = f_double(bw+1:end-bw, bw+1:end-bw, :);
red_outline_img = uint8(red_outline_img);
imshow(red_outline_img);
That'd be the output:
Another thing you could try is plot the lines as you suggest, which can be done very efficiently with some clever use of xlim/ylim, and then print the whole thing as an -RGBImage to get it back in image form.
The only caveat here though is that you will need to play with the formatting options to get what you're really after (e.g. in case you want higher or lower resolution), since you really are printing what's on your screen at this point.
E.g.
L = imread('leaf.png');
imshow(L)
hold on
plot( [xlim, fliplr(xlim);xlim, xlim], [ylim, ylim;fliplr(ylim), ylim], 'r', 'linewidth', 2 )
hold off
set( gca, 'position', [0, 0, 1, 1] );
set( gcf, 'paperposition', [0, 0, 1, 1] );
R = print( '-RGBImage' );
close
imshow(R); set( gcf, 'color', 'k'); axis off
I am using ggtern to graph some RGB data, where each point refers to the colour % from red, green or blue.
I was wondering if it is possible to change the colour of specific plot points to match the actual colour which they are representing?
I have tried using some ggplot2 commands but it doesn't work.
This is what I am using now:
library(ggplot2)
library(ggtern)
library(readxl)
Image9 <- read_excel("~/PhD/Image9.xlsx")
View(Image9)
ggtern(data=Image9, aes(x = Blue, y = Red, z= Green )) + geom_point( size=2,
shape=16, color="black") + theme_rgbw() + theme_hidegrid_major() +
theme_hidetitles()+ theme_rotate(degrees = 120) +
geom_text(aes(label=Colour), size=3, color="black", hjust=0, vjust=0)
Using this command I can plot the data as a colour intensity percentage in Red, Green and Blue and label the points so that I can map them back to the original image
1; representative image of plot.
Ideally I would like to plot each point as the same shade of color which they represent within the color space, I don't know if this is possible with this package.
Any suggestions would be greatly appreciated.
Say you want to put pixel with a color (R0 G200 B255) in a BMP picture and you have transp option in percents.
How do I determine the new pixel color, considering the transp and the background color?
I actually could figure out a formula that looks promising:
newpixel = newpixel + (bgpixel * transp) / %(transp of 255)
I created it by analyzing the pixel color change in GIMP. Not sure if that is the correct formula. I think it is also rounded up.
The standard formula is pixel = new_pixel * alpha + pixel * (1 - alpha), where alpha is a number between 0 and 1 that describes the opacity of the new (foreground) pixel.
You'll note that if the new pixel is fully transparent (alpha = 0) the pixel is unchanged and that if the new pixel is fully opaque (alpha = 1) the new pixel replaces the old one.
This formula must be applied separately for each pixel components (red, green and blue).
the code needs to change to 24 bit pixels.
where the 4th byte is the transparency factor.
The actual color values do not change
How can I bold the x and y axis values in jfreechart?
Have you tried one of those:
yourAxis.setTickLabelFont(new Font("Arial", Font.BOLD, 10)); //to define a specific font
or
Font bold = yourAxis.getTickLabelFont().deriveFont(Font.BOLD);
yourAxis.setTickLabelFont(bold); //to use the existing font, but bold
I have added values on x axis between 0-255. I add the values to a serie with serie.addXY(127,10000); When the chart is displayed, the values it shows on the x axis are -1, 49, 99...
How can I change this to display 0, 50,100?
Try setting axis bounds. You can do that in the designer or via code:
Chart1.ChartAreas["Default"].AxisX.Minimum = 0;
Chart1.ChartAreas["Default"].AxisX.Maximum = 255;