Re: is there size limit for displaying an image? - Graphics Discussion Boards

Thank you for the help.

i want to display an image which is over 400M size by the following ways:
1) GDI+
2)OPenGL (load the image as texture)

but it dosn't work, since i can display little size image by these two methods, is there size limit to display so big image?

thanks

Hi,

what is the size of your image (width and height in pixels)?

Lao Wang wrote:
it dosn't work

What does that mean? Do you have code that does not compile, if so show the error message.
Do you get an exception at run-time, if so show us the code and the entire
exception.ToString().

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

this months tips:
- use PRE tags to preserve formatting when showing multi-line code snippets
- before you ask a question here, search CodeProject, then Google

thanks Pattyn:

the size of my image is 29000*15000.

there is no compile error, no run-time exception yet.

i can display an image of 9000*5000 size through GDI+ and OpenGL, but display nothing with the big image of 29000*15000.

so i want to know is there size limit of displaying an image by GDI+ and OpenGL? Smile | :)

Is it possible to break the picture down into smaller tiles ( I doubt the user is looking at the whole picture at once )?

"Real programmers just throw a bunch of 1s and 0s at the computer to see what sticks" - Pete O'Hanlon

thanks

maybe i have to divide the big image into some little images before display it.

Adobe applications can display images that large, but nothing I've tried under win32 (including several OSS apps that could do it under *nix(64?)) was able to load the one image that big that I tried. I assume they're using some sort of divide and conquer approach instead of just trying to use the API native constructs.

--
If you view money as inherently evil, I view it as my duty to assist in making you more virtuous.

Lao Wang wrote:
i want to display an image which is over 400M size by the following ways:

"display" is relative to your display, which theoretically is probably maxing out at 2560x1600 assuming a very nice monitor. Parse is another issue.

One method is through a form of Level of Detail mapping for imagery, you can zoom into any portion of a very large image, yet not have anything more than 512x512 on any given cell. You break the cells into quads and those quads into quads, and those quads into quads, etc. until you reach full resolution. Then the hard-part is paging those in and out. Real memory becomes a cache for tiles loaded off disk. Now you can pull any given section rapidly. The primary advantage of tiling is that it allows you to combine multiple things all tiled off the same zone. This is extremely common for imagery related to terrain as terrain elevation can be tiled as well as imagery, perhaps as well as soil, or vegetation, or other layers of information. Each layer of information may have a different size, but be tiled the same. Elevation could be 64x64 while satellite imagery 512x512, while soil types are 32x32 and vegetation 64x64. Tiling is common for two sources together, and more common the more layers you have to use together. It is very difficult and often expensive (performance wise) not to tile multiple layers.

Another method is through windowed compression. This is probably the easiest, though depending on the data source not always as good looking. ECW free version limits your images to 500M which is within your limits. A GNU license or commercial license will buy you unlimited sizes (limited by your hardware of course). ECW and Jpeg2000 are wavelet compression which is very easy to window. You can then store the entire image on disk as compressed wavelet information, and extract the "window" of the visible portions of the image.

ECW and Jpeg 2000[^]
Tiling textures[^]
Image Clipmapping[^]
ChunkLOD Implimentation (images and elevation data)[^]

_________________________
Asu no koto o ieba, tenjo de nezumi ga warau.
Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)

El Corazon wrote:
"display" is relative to your display, which theoretically is probably maxing out at 2560x1600 assuming a very nice monitor.

He could be working with super premium type monitors used for medical imaging, etc. I know those can reach at least 8 megapixels.

--
If you view money as inherently evil, I view it as my duty to assist in making you more virtuous.

dan neely wrote:
used for medical imaging, etc. I know those can reach at least 8 megapixels.

If I recall those max out at 3500x3500 monichrome or about 10+ megapixels. Okay, even assuming that monitor, the task is still the same. I regularly show full scale NASA blue marble next gen earth images, http://earthobservatory.nasa.gov/Newsroom/BlueMarble/BlueMarble_monthlies.html[^] at 86400x43200 for the 500m per pixel version. No matter what monitor you have, you can't show that image. We do have one live-camera that takes 4096x3072 images, we display it on a group of monitors. Even with that, you might have to partition the image live on each monitor so that you can see it on multiple computers. Once you have the partitioning technique down, you can do live displays of any resolution on any monitor, or group of monitors.

There are similar techniques for volumetric medical imaging, though no mention of that has been made here. The concept is still the same. Massive data is needed to view in zoom mode at full resolution, nothing held back. But zoomed out you can get away with a bit less data (no pun intended).

_________________________
Asu no koto o ieba, tenjo de nezumi ga warau.
Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)

GDI+ is probably too naive to handle the image size on its own, or much too slow. There is no reason why it couldn't deal with it, in theory.

OpenGL is limited by your texture memory. No textures bigger than the texture memory can be loaded. You will want to load the file into memory (regular) and split it up, swapping out sections as needed.

Setting up a texture in OpenGL moves data from RAM to VRAM and freeing the texture id will release it from VRAM so that you have space to load another etc... 4GB of RAM (page file) should be plenty enough for a 400M image.

This kind of resolution is enormous, if you are going to put it all on screen at once I would recommend downsizing it first, i.e. pre-build files which are downsized, otherwise you will have the same memory problems, not to mention the ugly aliasing effects.

Hope this helps.

Everything I try just ends up failing. I have a 3d file with bones and a mesh with key frames in a .X(directX mesh file). I can render a sigle mesh. However when it is animated I can't.

I looked in the sample code provided with DirectX smaple (Simple animation) which isnt simple at all. I understand coding well and how 3d graphics work and alot of directX. I just cant for some reason get an animation to render.

Advice, links, downloads, any thing that will point me in the right diretion will be helpful.

I feel like I been around the web and back a few times trying to find this.

Sigh | :sigh:

hii.. is there any application by which we can divide the computer screen into two or more parts so that we can see more the two application simultaneously running on the screen. Please do reply if any body has any idea or any linl regarding this.. Thanx

prashant

prashant

Hi,

Prashant, what tools you are using? If using OpenGL with C++/VC++ it can be done, by creating two windows, you will have to manually adjust their size, and preferably you will like to disable the Maximize option for them.

Regards,

Adeel

according the GPS position information, i want to splice two images. but the two images have diffrent color palette, i can not simply replace or add one image's pixels with another image's pixels.
anyone can give me some suggestion?
thanks

Quick and dirty : you could do an pixel average between the 2 images.

Maximilien Lincourt
Your Head A Splode - Strong Bad

using VC++, how to cut a rectangle segment picture from an bmp format image?
and the cutting rectangle can has diffrent angle. my mean is that the cutted image is certainly rectangle, and the cutting segment is also rectangle, but the tow rectangles are not parallel, there is a rotated angle between them.

thanks

Wouldn't this be more suited to the C++ forum since you're asking a C++ specific question.

My Blog[^]

There are two things I think you could be wanting to do here. I assume you don't want to draw a rotated black rectangle over the image, but want to get a rotated bit of the image

This is quite drawn out to explain if you don't have much experience with graphics already...

What you want to do is take the rectangle you want to cut and work out coordinates for the pixels, translate and rotate them (rotation matrix - google) and interpolate (bilinear interpolation - google it) between the neighbouring pixels in the original image to find the new pixel values.

I would give a full explanation, but if you are a graphics programmer you should already be familiar with these ideas.

Hope this helps.

thank you Jheriko++:

maybe i didn't describe my question clearly. assume i have a big image which is rectange, i want to cut a segment image from the big image, the segment image is also rectance, but the borders of the segment rectange are not parallel with the big image borders.

but from your explain, i think you first cut a rectange image from the big image, and then rotaed it.

wish you understand my opinion. Smile | :)

Hi all, I'm facing problem with the C++ code which i've included below!! I need to output the RGB values of each pixel(preferably in array form), but I'm not sure how to use the getPixel here to output values of each point in terms of R, G and B separately. Is there any other better functions to use or do ya have any idea how i could manipulate this function to my program??

The block i tried below on GetRValue(&image), GetGValue(&image) and GetBValue gives me a hexadecimal value for the first 2 but i cannot seem to compile when i tried to do the same -->GetBValue(&image).

Thank You~~

Regards,
Stressed One

#include <windows.h>
#include <iostream.h>
#include <cimg.h>
#include <stdio.h>

using namespace cimg_library;

HANDLE hfile;
DWORD written;
BITMAPFILEHEADER bfh;
BITMAPINFOHEADER bih;
RGBTRIPLE *image;

int main() {
int size, x,y, crColor;
float R,G,B;
double hf;

// Open the file
hfile = CreateFile("bear.bmp",GENERIC_READ,FILE_SHARE_READ,NULL,OPEN_EXISTING,NULL,NULL);

// Read the header
ReadFile(hfile,&bfh,sizeof(bfh),&written,NULL);
ReadFile(hfile,&bih,sizeof(bih),&written,NULL);

// Read image
size = bih.biWidth*bih.biHeight; //allocate memory for the image
ReadFile(hfile,NULL,size*sizeof(RGBTRIPLE),&written,NULL); // Reads it off the disk
cout<<"The image width is "<<bih.biwidth<<"\n"; output="" the="" width="" of="" bitmap
="" cout<<"the="" image="" height="" is="" "<<bih.biheight<<"\n";=""
="" load="" image
="" cimg<unsigned="" char=""> image("bear.bmp");
CImgDisplay main_disp(image);

while (!main_disp.is_closed) {
main_disp.wait();
int getPixel(int x, int y);

R = GetRValue(image);
G = GetGValue(image);
B = GetBValue(image);

printf("%02X %02X %02X\r", GetRValue(image), GetGValue(image), GetBValue(image));
}

return 0;
}

Check the prototype of GetRValue, GetGValue and GetBValue, they return a BYTE from a DWORD rgb color.

other than that, I have not looked further at your code.

Maximilien Lincourt
Your Head A Splode - Strong Bad

There's a bunch of problems with this code.

The code that reads the BMP makes alot of assumptions about the
BMP file format so it's going to fail in many instances.

Then the file is reloaded as a CImg object. Why?

There's no code anywhere that actually gets a pixel value from the bitmap.

...

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

OK, lets get the laughing out our systems now. I can't load a cube (I'm new to XNA, but know a little C#). I'm following an article on CodeProject but it won't load the model ( iahve it a different name, but I made it so it SHOULD work) But, C# keeps saying it can't find the model in the folders.

protected override void LoadGraphicsContent(bool loadAllContent)<br />
        {<br />
            if (loadAllContent)<br />
            {<br />
                Player_Model = content.Load<Model>("Content\\Models\\Cube");<br />
            }<br />
        }<br />

I clearly stated them in the solution explorer... Help? Thanks in advance.

The most knowledge doesn't mean the most wise...

Didn't you forget the file extension ?

Cédric Moonen
Software developer

Charting control [v1.2]