I have an image in which certain area is highlighted by red colour as shown:
I want to fill it with black colour. The code which I have used to highlight the area is:
image= read('image.jpg');
figure,imshow(image);
cropped=image(200:240,100:480,:);
thresh=200;
lw=im2bw(cropped,thresh/255);
lw=bwareaopen(lw,100);
[B,L]=bwboundaries(lw,'noholes');
numRegions=max(L(:));
stats=regionprops(L,'all');
shapes=[stats.Eccentricity];
g=[stats.MinorAxisLength]
q=[stats.MajorAxisLength]
u=[stats.Orientation]
keepers=find(abs(u)<12);
imshow(cropped)
for index=1:length(keepers)
outline=B{keepers(index)};
line(outline(:,2),outline(:,1),'color','r','LineWidth',2);
end
How can I use imfill command to fill it as I have only the outline of the highlighted area.
Related
For instance, below image, a photo is background, and there is a character 'Iniesta' at the center of the photo.
But the character is some hard to read because the color is not good.
Is there any good algorithm for getting color to make character on image outstanding?
Instead of making a rectangular background (that indeed doesn't look very nice) you could use this trick:
Pick two contrasting colors (e.g. white and black)
Stroke the text using first color and a wide pen (e.g. 5 pixels)
Draw the text filled using the second color
If you cannot stroke the text with a wide pen an alternative is drawing the text multiple times with small offsets; e.g. (Python)
for dy in range(-3, 4):
for dx in range(-3, 4):
draw_text(color1, x+dx, y+dy, message)
draw_text(color2, x, y, message)
For example a one-pixel border would look like this...
Here's another idea: choose a box around your text area, or the whole image if it's relatively homogeneous in color. Now compute the average color in this area by summing up the color values and dividing by the number of pixels.
Now choose a color which contrasts well with this average color. For instance, you could use the simple formula (255-r,255-g,255-b) to get a contrasting color. However, this would fail if the average color is close to 128-gray, so you'd need to special-case on that.
Another way is to convert the average color into HSL or HSV color space, and then play with the hue; for instance, just add 180 to it, and/or invert the "lightness" (value/luminosity). Again, you'd need to special-case the grayscale (saturation close to 0) cases.
There are many approaches that differs for static and dynamic scene. I assume static image so i focus on that. here some basic approaches:
Paper area
clear space behind text with paper color and render text with ink color as you mentioned this is not cool for complex images.
Stroke,shadows,3D
render text with 2 colors. Inside with text color and stroke with contrast color to it. If you do not have the capability then you can render character with bigger font/boldness size in stroke color first and then overwrite with smaller font size with inside color +/- shift the position to center the fonts. The shifting method determine if you render stroke or shadow or even 3D text can be achieved like this
Transparency
Instead of render pixels of text by constant color add some color value to the original pixel color. You can also substract color or use alpha mixing instead ...
XOR
instead render pixel with color XOR the original color with another color or by white
This is how it looks like:
Here the source in VCL/C++:
void TMain::draw()
{
if (!_redraw) return;
// needed variables
AnsiString txt,a;
TColor c0=clBlack,c1=clWhite;
int tx=50,ty=50,tys=30,dty=tys*1.5;
int x,y,x0,x1,y0,y1,i,b;
// clear whole image
bmp->Canvas->Brush->Color=clBlack;
bmp->Canvas->FillRect(TRect(0,0,xs,ys));
// copy photo
bmp->Canvas->Draw(0,0,in);
// render texts ...
txt="Paper area ";
bmp->Canvas->Font ->Size=tys;
bmp->Canvas->Font ->Color=c1;
bmp->Canvas->Brush->Color=c0;
bmp->Canvas->Brush->Style=bsSolid;
bmp->Canvas->TextOutA(tx,ty,txt); ty+=dty;
txt="Stroke";
bmp->Canvas->Brush->Style=bsClear;
for (x=tx,y=ty,i=1;i<=txt.Length();i++)
{
a=txt[i];
// stroked char
bmp->Canvas->Font ->Size=tys+3;
bmp->Canvas->Font ->Color=c0;
bmp->Canvas->Font ->Style=TFontStyles()<<fsBold;
x0=bmp->Canvas->TextWidth(a);
y0=bmp->Canvas->TextHeight(a);
bmp->Canvas->TextOutA(x,y,a);
// inside char
bmp->Canvas->Font ->Size=tys;
bmp->Canvas->Font ->Color=c1;
bmp->Canvas->Font ->Style=TFontStyles();
x1=bmp->Canvas->TextWidth(a);
y1=bmp->Canvas->TextHeight(a);
bmp->Canvas->TextOutA(x+((x0-x1)>>1),y+((y0-y1)>>1),a);
// next char position
x+=x0;
} ty+=dty;
txt="Shadow/3D text";
bmp->Canvas->Brush->Style=bsClear;
bmp->Canvas->Font ->Size=tys;
bmp->Canvas->Font ->Color=c0;
for (i=0;i<5;i++)
bmp->Canvas->TextOutA(tx-i,ty+i,txt);
bmp->Canvas->Font ->Color=c1;
bmp->Canvas->TextOutA(tx,ty,txt); ty+=dty;
Graphics::TBitmap *tmp=new Graphics::TBitmap;
tmp->PixelFormat=pf32bit;
tmp->HandleType=bmDIB;
txt="Transparent";
tmp->Canvas->Brush->Style=bsSolid;
tmp->Canvas->Brush->Color=0x00000000; // max black
tmp->Canvas->Font ->Size=tys;
tmp->Canvas->Font ->Color=0x00808080; // color offset
x=bmp->Canvas->TextWidth(txt);
y=bmp->Canvas->TextHeight(txt);
tmp->SetSize(x,y);
tmp->Canvas->FillRect(TRect(0,0,x,y));
tmp->Canvas->TextOutA(0,0,txt);
union col { DWORD dd; BYTE db[4]; } *p0,*p1;
for (y0=0,y1=ty;y0<y;y0++,y1++)
{
p0=(col*)tmp->ScanLine[y0];
p1=(col*)bmp->ScanLine[y1];
for (x0=0,x1=tx;x0<x;x0++,x1++)
for (i=0;i<4;i++)
{
b=WORD(p0[x0].db[i])+WORD(p1[x1].db[i]);
if (b>255) b=255;
p1[x1].db[i]=b;
}
} ty+=dty;
txt="XOR";
tmp->Canvas->Brush->Style=bsSolid;
tmp->Canvas->Brush->Color=0x00000000; // max black
tmp->Canvas->Font ->Size=tys;
tmp->Canvas->Font ->Color=0x00FFFFFF; // max white
x0=bmp->Canvas->TextWidth(txt);
y0=bmp->Canvas->TextHeight(txt);
tmp->SetSize(x0,y0);
tmp->Canvas->FillRect(TRect(0,0,x0,y0));
tmp->Canvas->TextOutA(0,0,txt);
bmp->Canvas->CopyMode=cmSrcInvert;
bmp->Canvas->Draw(tx,ty,tmp); ty+=dty;
bmp->Canvas->CopyMode=cmSrcCopy;
delete tmp;
// render backbuffer
Main->Canvas->Draw(0,0,bmp);
_redraw=false;
}
it uses just VCL encapsulated GDI things so it should be clear enough...
bmp is backbuffer image
in is your image
tmp is temp image for custom combining the text and image
I am modifying images in matlab and I have a problem.
I need to separate the 3 channels of color and modify them separately.
I use this to obtain the three channels:
a = imread('./images/penguins.png');
colorlist = {'R','G','B'};
subplot(2,2,1);
imshow(a);
for k=1:3
subplot(2,2,k+1);
imshow( a(:,:,k));
title(colorlist{k});
end
a(:,:,k) is one color of the three. The problem is when I add the three vectors in one, to obtain the color image. I do this:
A=a(:,:,1)+a(:,:,2)+a(:,:,3)
figure; imshow(A);
But it dont works, it only show me a very highlight image, no a color image.
Anyone knows how can I recover the color image? Thanks for yout help^^
You are adding the values of the three layers instead of concatenating them in a 3D array.
Try this:
A= cat(3, a(:,:,1), a(:,:,2), a(:,:,3));
I should also note that you can edit the layers simply by indexing, say you want to switch the red and green components:
I1 = imread('http://i.stack.imgur.com/1KyJA.jpg');
I2=I1;
I2(:,:,1)=I1(:,:,2);
I2(:,:,2)=I1(:,:,1);
imshowpair(I1,I2, 'montage');
Now if I take your title literally, let's say you do want to add the three layers and display the result with a colormap, you can do:
A=a(:,:,1)+a(:,:,2)+a(:,:,3)
imagesc(A); axis image;
colorbar;
Results:
I want develop an matlab's application that can show the bounding box to the object in the image.
I have detected the object, and cropped it.
And now, for the boundng box, i just have to add 10 in all my pixel.
For exmpl:
x=x+10;
y=y+10;
w=w+10;
h=h+10;
I use imcrop function.
But the problem is that i dont understand how to get the pixel's coordinates from imcrop.
[I_crop, I_rect]=imcrop(ImSeq(:,:,1),[])
I_rect=floor(I_rect);
final_rect=I_rect;
for t=1:NumImages
cur_r=final_rect(2);
cur_c=final_rect(1);
for r= cur_r -10:cur_r+10
for c=cur_c-10:cur_c+10
temp= abs(I_crop-ImSeq(r:r+I_rect(4),c:c+I_rect(3),t));
what is final_rect(2), final_rect(1), I_rect(4) and I_rect(3)?
How i can get the coordinates of x,y,w,h of the cropped image??
Thanks
In [I2 rect] = imcrop(I), rect is the cropping rectangle, a four-element position vector. Within the original image, the cropped area is defined by:
rect(2) the current row
rect(1) the current column
rect(3) is the width
rect(4) the height.
I want to fill color in an NSBox on slider movement.
I am using the following code.
-(IBAction)slider1move:(id)sender {
[self.box setFillColor:[NSColor colorWithCalibratedRed: ([self.slider1 floatValue])/255.0 green:0.0 blue:0.0 alpha:0.0]];
}
Please correct me. I have three sliders in my application with each correspond to red , green and blue color.
How do I fill the color in the box on slider movement based on the current value of slider.
Like if my slider showing value of 50 the box should be half filled with red color if it is for red color.
First, make sure you've met the requirements listed in NSBox's setFillColor: documentation:
Functional only when the receiver’s box type (boxType) is NSBoxCustom
and its border type (borderType) is NSLineBorder.
Assuming that's not the problem, a quick guess would be that you may need to call setNeedsDisplay: on the box to get it redrawn with the new color.
Look at Your color, You set fully transparent color - alpha to 0.0 that's why Your color it's not changing.
Change Your color to alpha 1.0 like this:
[NSColor colorWithCalibratedRed: ([self.slider1 floatValue])/255.0 green:0.0 blue:0.0 alpha:1.0]
I am using jqplot to draw multiple lines of different line colors.
Also, I have legends whose colors should be in accordance with the corresponding line colors.
I seem to find no way to cope with the legend color.
So any hint?
Taken from the question title I understand you want to change the color of legend labels to correspond to the color of series, right?
For this reason, since the swatches which are just in front of the labels, we can use them to grab the color which we then set for the labels.
This is the bit of the code you need. You need to remember to put it before you draw your plot.
$.jqplot.postDrawHooks.push(function() {
var swatches = $('table.jqplot-table-legend tr td.jqplot-table-legend-swatch');
var labels = $('table.jqplot-table-legend tr td.jqplot-table-legend-label');
labels.each(function(index) {
//turn the label's text color to the swatch's color
var color = $(swatches[index]).find("div div").css('background-color');
$(this).css('color',color );
});
});
You could see the code running live here.