I have an image of size 640x480 pixels. It's possible to obtain the dimension in mm of one pixel from that image given only that size?I do not have the size of the image in mm,however.
I try to write code for one problem which is worked with the matrix.I have written in specific size 5 by 5 and I know the general formula for these matrix based on dimension,I want to write a general form that take the matrix size and then create my favor matrix.However,when I write like below the following error is appeared
I am trying to figure out the syntax to dynamically allocate a single dimension of a triple dimensional array. Basically i have a 2D array of structs. but each struct is an array (basically rows of the information). The rows of this structure need to be allocated dynamically, but the height and width of the overarching structure are static.
Basically: Struct * ts_FieldInfo[100][100] = new Struct[Class.returndataitems()];
Want to initialize a local one dimensional array. How can I do the same without a loop?
Found from some links that int iArrayValue[25]={0}; will initialize all the elements to ZERO. Is it? If yes then can we write below code to initialize the elements to a non-ZERO value?
int iArrayValue[25]={4};
Do we have some other way to initialize an array to a non-ZERO value? Memset can initialize the element to ZERO.
I would like to create N matrices of dimension (n,k) simultaneously. Lets say for example that N=3. I read the command a[n][k][N] but I don't understand how to use it.
I know that for some of you this question is silly but I' m new to this language and I have noone else to ask.
I would like to print a multiplication table, with the dimension n given as input. I attached how the table looks like for n=7.
How do you output the character "-" in that sequence? The first and last numbers have 13 "-" characters before and after them, but the numbers in between have 8 "-" characters.
I am trying to read in data from a text file and store it inside a 3D array. The text file looks like this: bar bell orange bell bell 7 lemon cherry cherry
I can read in the data fine, but how to store it inside the array. My array looks like : [ Char slotMachine[10][3][8]; ] T
he dimensions are Row, Column, and symbol. There are 10 rows and 3 columns inside the file. The third dimension is supposed to hold the symbols as a C-style string.
This is what I have been trying:
char symbol[8]; int rowIndex = 0, colIndex = 0; While(fin.good()){ fin >> symbol; slotMachine[rowIndex][colIndex][] = symbol; rowIndex++; colIndex++; }
I know that i'm not storing the symbol right. How to correctly store it inside the third dimension.
I am working on image processing in C + + and opencv, I treat images in grayscale, ie the pixel values it must be between 0 (black) to 255 (white).
Mat img; img = imread (file, -1); for ( int i = 0; i < img. rows ; i ++) { for ( int j = 0; j < img. cols ; j ++) { val_pixel=img.at < double >(i,j); printf( "%d ",val_pixel); } printf( " "); }
when displaying the pixel value from two loop, I get values to 0 and it is normal for propablement black areas, but for whites I find the value -2147483648. I don't understand why this value is not 255.Is there an explanation for this has value.
I have a set of n- dimension point store in `vector< vector<double> >`
ex A[0][1].............[N], and A[0][0] = X, A[0][1] = Y, A[0][2] = Z
and I want to sort the vector of all of the dimension
ex sort X, Y, Z ,.........N in ascending order
ex A[0] = (1,5,3), A[1] = (3,2,1) A[2] = (2,8,4) after sorting index: 0 1 2 A[0] = (1,5,3), A[1] = (2,8,4) A[2] = (3,2,1) original index : 0 2 1
I find that `sort(vector.begin(), vector.end())` can sort it but how can I record the original index with a additional vector?
Is there a algorithm or C++ feature can solve it?
I have tried to solve it with a class wrapper it but I don't know how to write the compare function.
class point{ public: point(int totalLength = 0, int elementLength = 0); vector<vector<double> > pointSet;//store the n-D points vector<double> pointIndex;//store the index }; point::point(int totalLength, int elementLength){ pointSet.resize(totalLength,vector<double>(elementLength, 0)); pointIndex.resize(elementLength); }
I wrote a script that generates n random pixel positions and draws them to the screen. Works well. Now i tried to rotate them. Rotating does work too. But it does not work as i planned it.
paramters 'angle' and 'timestep' work somehow, but not as they should do. the function 'move' is supposed to rotate the pixelfield 'angle' degrees in a given direction, addicted to the 'timestep' parameter. 'timestep' is needed time for drawing in one single game loop.
rotation point is the middle of the screen. when i set angle to 10 it should rotate 10 degrees / second. Instead it's rotating very very fast and all stars are moving nearer to the center of the screen, so after x rounds there is just 1 pixel left in the middle of the screen. there is a kind of gravition.I'm working with SDL2. What I did find out:
FPS is <= 60, 'cause of the 'SDL_RENDERER_PRESENTVSYNC' flag. When i skip that flag, for any reason the 'gravition' would take more time. FPS is <= 1400 then, 'though i got a natural game loop (i hope):
I am writing a class which loads a bitmap image into a one dimension char* array.
This class has methods to allow for resampling and cropping the image before saving the bitmap image. It works perfectly for all images in which the width is divisible by 4. However when the width is not divisible by 4 the resulting bitmap is all mixed up.
I have spent much of the day googling this problem but to no avail. I know it is a problem with making sure the scanlines are DWORD aligned, and I believe I have done that correctly. I suspect that the problem is that I need to take the padding into account during the crop for loops but am lost to how to do this.
BTW: Coding on Linux using GCC
The following code is a cut down version from my bitmap class. I have removed methods which are not needed to make reading a little easier.
#include "BMP.h" // FIXME (nikki#1#): Portrait bug on images of specific sizes // TODO (nikki#1#): Memory leak checks // THIS METHOD WRITES A BITMAP FILE FROM THE CHAR ARRAY . bool BMP::saveBMP(string fileName, string *err) { FILE *filePtr;
Im new to c#. In c++ I have made a window and painted it with dots and concentric circles, like a radar PPI screen. Trying to do this in c#, I can't find how to draw a single pixel on the window.
Also, what should I be drawing on: the form, panel, picturebox...?
I would like to subtract one image from another to get something like "differential picture" (i am not sure whether the name is correct). I've managed to read the FILEHEADER and FILEINFOHEADER of bitmap. I will subtract 24-bit bmp files only. However i can't understand the structure of this file. So far my code looks like this. Any example of at least copying one bmp file to a new one? This example would be useful, because subtracting will be simillar, instead of copying the pixel value i will just put abs(value1-value2) in the output.
Code:
// ConsoleApplication1.cpp : Defines the entry point for the console application. #include "stdafx.h" #include <iostream> #include <fstream> using namespace std; struct BITMAPfileHEADER {
//Casting a void pointer pointing to an array of memory locations(the pixels), to a pointer to an array of Uint8's. //SDL_MapRGB() Returns an Uint32 containing the color 0,0,255,(0/255, i think it returns the transparency too, or else it would rather return a Uint24,not sure).
Then modifying the memory location, in this case the pixel at the middle of the window.
What i seem to not understand is that, i cast pixels to Uint8*, which means I now have a pointer to an array of 8bit numbers, but SDL_MapRGB seemingly returns an Uint32 or Uint24 for a color composed of r,g,b, together without 'a' is 24bits(256=1b,256=1b,256=1b)=3b.
And then i somehow assign that pixel which is of 8bit at chosen location, an Uint24 or 32bit unsigned int.
I'm currently working with linear VRAM (a buffer with 256KB memory, divided into four 64k planes, so plane 0 at 0x00000, plane 1 at 0x10000, plane 2 at 0x20000, plane 3 at 0x30000). Just add the index of the plane to that for the full address in VRAM.
I'm still wondering how to get a specific pixel from VRAM (x,y coordinate) when doing graphic modes (none color modes work, only the black/white pixels (1-bit) graphic mode works).
how I can get specific pixels from the VGA VRAM (having linear access described above) using Shift Register Interleave mode (VGA modes 4&5), 16-bit planar mode (Most VGA modes) etc.