I'm fairly new to GIMP
I have some black-and-white images in RGB mode. I want to highlight some areas in plain Red (ie, zero Blue+Green), some in plain Blue (ie, zero Red+Green), and the rest in plain Green (ie, zero Red+Blue)
I will be selecting several areas using Paths, though a simple rectangle would be fine for now
The final image will be Green, with 2+ selections of Red, and 2+ selections of Blue
I have experimented with multiple layers & multiple images, but I always get problems with the selection areas
Thanks in advance !
If what you want is keep the value of the R (or G or B) channel in the selection, while setting the other two components to 0:
Create a layer group above your image layer
Add a transparent layer in the group, name it "Green", bucket-fill with green
Add a transparent layer in the group, above "Green", name it "Red+Blue"
Set the group to "Multiply" mode. You should see your image in green.
To add red/blue, make a selection, make sure "Red+Blue" is the active layer, and bucket fill the selection with Red or Blue.
Notes
With some selection tools, (path, ellipse...) you may have to use Select>Sharpen before the bucket-fill to make sure that there are no partially selected pixels
To see the original image when making selections, just make the group invisible.
You can also use two separate layers for Red and Blue (both above the Green one, in the layer group)
If what you want is just areas of #FF0000 and #0000FF over a #00FF00 background, then just hide the initial image layer when exporting.
Related
I have a table like this one: https://docs.google.com/spreadsheets/d/1Kn4vfbHwpif7u-6ZTznFpBJFNHhnStETPIQVyQq8xgY/edit#gid=0 with bottom / top color and the Red, Green, Blue (RGB) of the result (where it states 'Preparation' for the bottom color means the canvas so essentially its the RGB of the top color - those rows are the 'single colors').
I am looking for a relation between the double colors and the single colors. E.g. could I somehow subtract one color from their combination and get the other? Either by using the RGB values or using the images in some software?
Note that the type/formula/function/relation that I am looking for will be only for specific single colors and their combinations which I have already measured (do not care if it is valid beyond the dataset that I am working with)
I need to display an outline of a dog in a window. I then need to be able to change the colour for different part of the dog by inputting numbers into entry boxes- for example if I put a '1' in the 'head' entry box, the head changes to a yellow colour. The dog should be white by default.
I can just create 4 images (one for the head, body, legs, and tale) to change each part of the bod. I've thought about changing the rgb values of each image to change the colour, but this would also change the colour for the outline (meant to stay black). The only other thing I could think of was making a red, blue, green, yellow, blue, etc. version of each image (head, body, legs, tail), and then just displaying the red version of the image when I need to (and the same for other colours).
I need to know if there is any other way to do this (perhaps with the canvas widget?) before I code it because It will take a long time to change the colour of each image. I just have no idea where to start.
Thanks in advance for your answers
You will have to make different widgets for each part of the dog(e.g: Head, Abdomen etc.) and you will need different images for the dogs part and color, after that you can implement a button that changes the color with the 'if' function.
I have a grayscale image, which has a certain wanted pattern of colours + some unwanted colors.
The colors I want to leave are (rgb):
000
666
121212
181818
242424
303030
363636
424242
As you can see, there's a pattern. Umfortunately there are some really "hard to select" colors also. The colors are actually contours (curves for height changes of the terrain), so they would be really tiresome to edit manually. The image is 2048 x 2048 pixels.
How could I somehow limit the image just to have those certain colors and maybe even automagically convert the wrong ones to those wanted ones?
You could try converting the image mode to indexed color:
Then choose a custom pallet:
Then add your custom colors to the pallet. Set dither to none. It should convert all colors to the index color they are closest to.
To remove the white lines... convert mode back to rgb, use magic wand to select all white lines (uncheck contiguous and set tolerance to around 10). Then choose select>modify>expand and expand selection by 1 pixel. Now choose edit>fill and choose content-aware.
This should fill in the lines with the colors around them.
Set color to index again to clean up the blured shape edges.
Hope this helps.
I have two boxes filled with colors, a green one on the left, and gray one on the right. They go right up against each other in the middle of the screen, and I would like each one to extend the width of the browser, so the green one extends all the way to the left, and the gray one extends all the way to the right, no matter how wide the browser gets. How can I do this?
the width property supports percentage values, which are relative to the size of the window it exists in.
See:
http://learnlayout.com/percent.html
http://www.w3schools.com/cssref/pr_dim_width.asp
I have more then 1 week reading about selective color change of an image. It meand selcting a color from a color picker and then select a part of image in which I want to change the color and apply the changing of color form original color to color of color picker.
E.g. if I select a blue color in color picker and I also select a red part in the image I should be able to change red color to blue color in all the image.
Another example. If I have an image with red apples and oranges and if I select an apple on the image and a blue color in the color picket, then all apples should be changing the color from red to blue.
I have some ideas but of course I need something more concrete on how to do this
Thank you for reading
As a starting point, consider clustering the colors of your image. If you don't know how many clusters you want, then you will need methods to determine whether to merge or not two given clusters. For the moment, let us suppose that we know that number. For example, given the following image at left, I mapped its colors to 3 clusters, which have the mean colors as shown in the middle, and representing each cluster by its mean color gives the figure at right.
With the output at right, now what you need is a method to replace colors. Suppose the user clicks (a single point) somewhere in your image, then you know the positions in the original image that you will need to modify. For the next image, the user (me) clicked on a point that is contained by the "orange" cluster. Then he clicked on some blue hue. From that, you make a mask representing the points in the "orange" cluster and play with that. I considered a simple gaussian filter followed by a flat dilation 3x5. Then you replace the hues in the original image according to the produced mask (after the low pass filtering, the values on it are also considered as a alpha value for compositing the images).
Not perfect at all, but you could have a better clustering than me and also a much-less-primitive color replacement method. I intentionally skipped the details about clustering method, color space, and others, because I used only basic k-means on RGB without any pre-processing of the input. So you can consider the results above as a baseline for anything else you can do.
Given the image, a selected color, and a target new color - you can't do much that isn't ugly. You also need a range, some amount of variation in color, so you can say one pixel's color is "close enough" while another is clearly "different".
First step of processing: You create a mask image, which is grayscale and varying from 0.0 to 1.0 (or from zero to some maximum value we'll treat as 1.0), and the same size as the input image. For each input pixel, test if its color is sufficiently near the selected color. If it's "the same" or "close enough" put 1.0 in the mask. If it's different, put 0.0. If is sorta borderline, put an in-between value. Exactly how to do this depends on the details of the image.
This might work best in LAB space, and testing for sameness according to the angle of the A,B coordinates relative to their origin.
Once you have the mask, put it aside. Now color-transform the whole image. This might be best done in HSV space. Don't touch the V channel. Add a constant to S, modulo 360deg (or mod 256, if S is stored as bytes) and multiply S by a constant chosen so that the coordinates in HSV corresponding to the selected color is moved to the HSV coordinates for the target color. Convert the transformed S and H, with the unchanged L, back to RGB.
Finally, use the mask to blend the original image with the color-transformed one. Apply this to each channel - red, green, blue:
output = (1-mask)*original + mask*transformed
If you're doing it all in byte arrays, 0 is 0.0 and 255 is 1.0, and be careful of overflow and signed/unsigned problems.