Questions related to images, including creation and modification

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56
votes
5answers
17k views

Which image format is more memory-efficient: PNG, JPEG, or GIF?

Which image format is more efficient to save memory? PNG, JPEG, or GIF?
42
votes
7answers
3k views

Managing text-maps in a 2D array on to be painted on HTML5 Canvas

So, I'm making a HTML5 RPG just for fun. The map is a <canvas> (512px width, 352px height | 16 tiles across, 11 tiles top to bottom). I want to know if there's a more efficient way to paint the ...
37
votes
5answers
1k views

Best Way to allow players to “Dye” images without losing color quality?

I am creating a 2.5D isometric (2D images) game. I want the players to be able to "dye" their armor, clothes, and other things. I find that grayscaling everything leads to losing out on some of the ...
14
votes
4answers
1k views

Why would some PNG files extracted from games display incorrectly?

I've noticed extracting PNGs from some game files that the image becomes distorted part-way through. For example, here are a couple of PNGs extracted from the Textures file in Skyrim: Is this some ...
13
votes
6answers
2k views

How can I create a large space background that repeats, in an unnoticeable way

How can I create a large space background that repeats for an rts game. I want to have complex nebulae and dust fields also, but since the units will have lots of space to explore I can't have a ...
11
votes
1answer
889 views

How can I get the palette of an 8-bit surface in SDL.NET/Tao.SDL?

I'm looking to get the palette of an 8-bit surface in SDL.NET if possible, or (more than likely) using Tao.SDL. This is because I want to do palette swapping with the palette directly, instead of ...
10
votes
2answers
220 views

Should the color of a texture be adjusted for display on a television?

If a 24bit RGB image with a range of 0-255 per channel is displayed on a television that displays a range of approx. 16-235 per channel, color detail will be lost, correct? If so, should images be ...
8
votes
3answers
681 views

Why is it possible to encounter a texture coordinate greater than 1 or less than 0

I'm studying a text about texture mapping and in the preparing to draw session, I read: Define the texture wrapping parameters. This will control what happens when a texture coordinate greater than ...
7
votes
5answers
1k views

Is there a game oriented graphics or image editor?

I remember looking a few times over the years for an alternative to Photoshop for editing images. I've tried using Gimp too, and that's also not quite sufficient. There are some problems that have ...
7
votes
2answers
2k views

How can I resize pixel art in Pyglet without making it blurry?

I have a tileset of 8x8 pixel images, and I want to resize them in my game so they'd be double that (16x16 pixels, e.g. turning each pixel into a 2x2 block.) What I'm trying to achieve is a ...
7
votes
3answers
2k views

Storing a Hex Grid

I've been creating a small hex grid framework for Unity3D and have come to the following dilemma. This is my coordinate system (taken from here): It all works pretty nicely except for the fact I ...
7
votes
1answer
3k views

How to create a XNA texture from a GDI Image with source rectangle?

A Texture2D in XNA can only hold so much. Depending on which profile I use that limit is either 2048 or 4096 pixels wide. As far as I could tell from my research (someone correct me if I'm wrong) GDI ...
6
votes
4answers
3k views

Which image format to use for sprites in an HTML5 game?

In a 2D HTML5 game, what is the best image format to use and why? Should I use different formats in different situations? For example, .png for the background image, .jpeg for the animation frames and ...
6
votes
2answers
2k views

OpenGL 3.0+ framebuffer to texture/images

I need a way to capture what is rendered on screen, i have read about glReadPixels but it looks really slow. Can you suggest a more efficient or just an alternative way for just copying what is ...
6
votes
1answer
231 views

Can SFML load anything other than RGBA8888? (RGBA4444, RGB565, etc.)

I can't see this mentioned in the documentation. Am I missing something obvious? Or does SFML really give you no option, forcing everything to be loaded as RGBA8888? Searches on Google and the SFML ...
5
votes
1answer
560 views

Whats the point of all these Surface Formats

I am relevantly new to Graphics Programming. I have written some basic games in xna in the past but I am trying to understand what the point of all these surface formats is. For instance Xna and DDS ...
5
votes
1answer
374 views

Rendering scaled-down card images

I have high-quality SVG card images, but they drastically lose their quality when I downsize them. I have tried two ways of rendering cards (using Inkscape and Imagemagics): 1) Render SVG to high-res ...
5
votes
1answer
263 views

Split Texture2D Across Line

Background I'm using a texture as a damage map represented by an array of floats for displaying damage effects on a space ship in a process. An upside of this is being able to 'slice' ships in ...
4
votes
1answer
552 views

Should I be concerned about assets being accessed by dumping VRAM?

I have heard many people tell me that a user can dump the VRAM on their GPU and get all the images in my game. Including all "Streamed" images. This includes most of my Menu graphics. How would a ...
4
votes
6answers
2k views

How to get quality sprite sheet generation with rotations

I'm working on a game that uses sprite sheets with rotation for animations. While the effect is pretty good, the quality of the rotations is somewhat lacking. I exported a flash animation to png ...
4
votes
4answers
529 views

Can a high FPS negatively affect how a program runs?

Yeah I know this is a broad question and will get down rated, I'm just hoping for some answer before it gets closed. Anyway, I'm using Slick 2D/Java to play around with graphics. I'm having some ...
4
votes
4answers
3k views

Need a good quality bitmap rotation algorithm for Android

I am creating a kaleidoscopic effect on an android tablet. I am using the code below to rotate a slice of an image, but as you can see in the image when rotating a bitmap 60 degrees it distorts it ...
4
votes
2answers
731 views

Use large image individually, or in TextureAtlas?

Does it make any sense to include a large image (with dimensions of say 1920x1080) in a TextureAtlas and then use it with libgdx for example? Or should I rather use it individually and include the ...
4
votes
1answer
135 views

Image edges are distorted inside game

I dont know how to explain this, so I will use images to describe my problem. The image I made using InkScape: What it looks like in-game (ignore the runner): As you can see the edges are not ...
4
votes
1answer
504 views

How do I draw a zoomable image in OpenGL?

Up to now I have used glDrawPixels but since my image is a large geotiff one, I'm getting some horrible results for example: this is the code used for zoom extent: void ...
4
votes
1answer
2k views

How can I convert a 2D bitmap (Used for terrain) to a 2D polygon mesh for collision?

So I'm making an artillery type game, sort of similar to Worms with all the usual stuff like destructible terrain etc... and while I could use per-pixel collision that doesn't give me collision ...
3
votes
2answers
180 views

split pngs for sidescroller

I want to split a long png from my artist into vertical chunks that I can load into my code for a side scroller. Is there a tool that will help do that or do I have to do it manually?
3
votes
1answer
761 views

How can I optimize this flood fill algorithm?

I'm creating a sprite and animation editor like this one. I'm having performance issues with my flood-fill algorithm. Basically, I open an image with the different modules that are part of a frame of ...
3
votes
1answer
448 views

Pygame performance issue for many images

I've made a script for generating a game world based off of image pixel data. Trying to make a python map editor My progress so far has resulted in a program which loads an image and draws sprites ...
3
votes
1answer
385 views

What algorithms exist for generating collision geometry from an image?

I am currently working on a game using SFML and Box2D. I am interested in generating collision geometry from the sprite data that I load into SFML. So, for example, an algorithm that would do this ...
3
votes
1answer
423 views

Javascript tile map -> bitmap or JSON

I would like to know which idea is better in terms of performance. The map is 5000x5000 tiles and I plan to expand it even more. It is split into 50x50 regions and camera doesn't move with player, ...
3
votes
2answers
1k views

Splitting a texture atlas into seperate images [duplicate]

Possible Duplicate: How to decompose sprite sheet I'm doing a port of an existing game and the designer no longer has all of the original art; he only has the resulting texture atlases he ...
3
votes
1answer
196 views

Can I use one set of images to represent multiple sprites in Java?

I've got a game that has 3 basic sprites, at the moment I'm loading 8 images into each sprite for animating. Each character class has a sprite object. if I've got 10 characters on screen at once ...
2
votes
2answers
1k views

Best practice for image compression

Which is the best format or best technique to compress images without loss of quality for iPhone/iPad games?
2
votes
2answers
341 views

there is a BLOB standard to store images in memory?

I would like to abstract all the images in memory, to do so i would like to have just 1 format of reference without talking about the usual file formats for the filesystem like JPG, TGA, and so on. I ...
2
votes
1answer
354 views

When should I use color keying vs PNG transparency?

SDL (and other toolkits) can use color keying to make a certain color in an image transparent. Alternatively, you could load a PNG image that supports transparency. When should I use which?
2
votes
1answer
240 views

Basic knowledge for 2d gaming and images?

Can anybody refer me some pdf or ebook that i should follow for basic 2d programming and texture ,shaders and other gaming elements details in depth.By which i can easily get through the 2d game ...
2
votes
2answers
1k views

State of the art in image compression?

I'm looking for good algorithms for compressing textures offline (ie decompressing them at install or load time, I know about using DXT/3DC to save runtime video memory, but these create awful visual ...
2
votes
2answers
11k views

How do I make a background fill the whole screen in Libgdx?

I'm using this code to set a 800x420 image to be full screen: public void show() { float w = Gdx.graphics.getWidth(); float h = Gdx.graphics.getHeight(); camera = new ...
2
votes
1answer
4k views

Libgdx loading images

I can't find a sulotions that solves my problem, I've tried pretty much every tip I can find, but with no luck. Error : Exception in thread "LWJGL Application" ...
2
votes
2answers
312 views

How do you handle iPhone graphics for both high and low DPI settings?

How do you guys create your game graphics for iPhone? Considering you need a retina version and a nomal one? Do you create a big version of your image, save HD, then resize to smaller version, and ...
2
votes
1answer
50 views

SDL2 jagged/staircase edges

I am using SDL2 and SDL2 Image to render png images. When I rotate the textures, they turn out very ugly, like this: This is the code responsible for the rotation and alpha mod. SDL_Rect srcRect; ...
2
votes
1answer
129 views

Weird effect when generating gradients for height map

I am experimenting with generating height maps using radial gradients and perlin noise, using a technique I found here: ...
2
votes
2answers
211 views

Should I create generic bitmap/sound/et cetera wrappers for Allegro?

Basically, I have been writing a game in C++ using Allegro. I mostly just use the library to draw bitmaps, draw text, and play audio. My main concern as the game continues to grow code-wise, is that ...
2
votes
1answer
179 views

Getting an images rgb value at click

I'm not sure if this is at all possible, but maybe it will spark up an interesting conversation. (Sidenote: working on a small game in Löve). I'm making an archery shooting kind of game, and I was ...
2
votes
1answer
629 views

Does swf provide better compress rate than zlib for png image?

Somebody told me that when a png image is stored in swf, it's separated to several layer, hence the alpha channel can be compressed better. Is it true? Or, once png image is imported into a swf, it's ...
2
votes
1answer
166 views

Multiple images written and read from one meta-file?

Short version: I need a way to store multiple image files in one bigger file, to be used using C#, preferably easily compatible with XNA. The files will be read, written to, but also adaitional files ...
2
votes
1answer
115 views

How to combine image with a gradient? Or make it more featured in a different way

I generate an abstract 128x128 image, that is in general two-color (it uses values scaled between "blue" and "white", or other similar color pair). I need to make the image more "featured". ...
2
votes
1answer
158 views

Is there a way to export all the images of my tweening effect in Flash?

i'm using Flash to create the animation of my character in 2D (i'm just beginning). Is it possible to make a tween effect of a character, and then automatically export all the images/frames? So far, ...
2
votes
2answers
2k views

Dynamically load images inside jar

I'm using Slick2d for a game, and while it runs fine in Eclipse, i'm trying to figure out how to make it work when exported to a runnable .jar. I have it set up to where I load every image located in ...