Sender: flubber hopping vault horse, message area: ANSI Title: Bmp2Ascii Beginner Tutorial by flubber Sending site: Sun and Moon Guanghua Friday, September 19, 2003 11:34:56, site mail Please press space continuously to turn pages Zero Select material The skill of sharpening a knife and chopping firewood before making mistakes. Before making a picture, I need to sharpen it with everyone. ① Choose what kind of pictures are suitable for software conversion For novices, you should start with simpler pictures. Pictures with larger color blocks and simple shapes are easier to avoid. Pictures with many colors, complex shapes, very thin tips or lines, and complex changes in light and shadow The themes range from easy to difficult: logos, cartoons, still lifes, real landscapes, and real people. The logo of Shanghai Bank is chosen as an example. Please download the original gif image. http: bbs.sjtu.edu.cn showfile?name ShBank.gif 1 Modify the original image ① Why modify the original image? First, the image must be converted into bmp format before it can be used. More importantly, the original image has many factors that are not conducive to conversion. Modification can make subsequent modifications easier. For example, removing background and noise is very important. ② Why should we remove the background? One reason is that people on BBS are used to black backgrounds, while most pictures have white backgrounds, large-format white ones. It looks irritating on BBS Another more important reason involves the limitations of highlighting colors for painting, which will be discussed later. ③ How to remove background and noise Just use the drawing board that comes with Windows. To open the gif, just click with a paint bucket to create a simple background. That’s it. If there are some messy colored blocks on the picture, you can remove them manually. Our picture is very clean, very good. Processing: After clicking the paint bucket, there are still some bright edges left. It doesn’t matter much because the conversion accuracy is very low. These small noises do not have much impact and are easy to remove during manual modification. The modified picture can be found at http: bbs.sjtu.edu.cn showfile?name ShBank.bmp 2. Convert pictures ugly ① Why you must use highlight colors with caution when converting sawtooth An important rule in BBS is Highlight color cannot be used as background color The core secret of color block painting Just use the background color to compose the picture relatively ugly Compare the smoothing and aliasing of the two same parameters on the right The transferred picture clearly shows low brightness. Closer to the original image, the highlighted color is the easiest It is easy to make a lot of noise on the lower edge of the picture. Ugly jagged pictures like this It can only be described as unsightly. Image converted with low light color Image converted with high light color For the same reason we must Modify the image before converting it The background is also to avoid using bright white to cover a large area of ​​the background. It’s not that high-gloss colors cannot be used. They can only be used without causing major deformation. Newbies are advised to start with low-gloss colors. ② Carefully adjust the conversion parameters x rate, y rate is the magnification factor. Here we want to magnify 4 times Click Go! to get the picture on the left. Is this enough? No this There are many flaws in such rough results, but after precise adjustments, The picture on the right is much better flaw none flaw defect x rate 4 y rate 4 How to adjust x rate 3.9 Remember that the transformation graph is composed of color blocks. The vertices of the boundary should try to have a y rate of 3.9 Adjust to the edge of the grid and look at the grid in the dotted grid diagram. The x, y rate must be at least dx 1. Accurate to one decimal place dx,dy can translate the picture dy 1 Baldness 4 Manual Modification This is a very important step that cannot be skipped. Manual modification There are many techniques that require a lot of practice and experience build change flaw ① Outline The top and bottom are not sharp enough and there is exactly one space. We manually move the right half of the gap one position to the left ② Modify the upper half of the arc First look at the arc at the lower edge of the yellow part. Use horizontal lines of various heights to The color block can be smoothed. Pay attention to the curvature of the curve. build Not smooth enough. Change smoother The arc here is composed of color blocks with black foreground and yellow background. If you paint with highlight colors, you won't be able to do it here. Because highlight colors cannot be used as background colors, highlight painting is easily restricted. Tips: You can select a transparent color for modification without changing the current color. ③ Modify the arc in the lower half There are a lot of problems with the blue part. First remove the noise and then deal with it. Spikes. Three character blocks are used here to cover the spikes. build Variegated block change Not tactful spikes There are two ways to draw the three-character block. One is blue foreground and black back. The other one is black foreground and blue background, two effects There are subtle differences. Let's see who can tell. Smooth processing is the most difficult. There is nothing to say except try more and practice more. Four, you’re done Shanghai Bank Let’s add text and borders to modify it The final draft of the Shanghai Bank logo was completed. Pay attention to the decoration and don’t overwhelm the guest. Five homework 1 Use the same picture to draw one The Shanghai Bank logo magnified about 5 times 2 Draw a Shanghai Pudong Development Bank Find the picture of the logo of Bank of Shanghai online. wan Source: Sun and Moon Guanghua bbs.fudan.edu.cn [FROM: 159.226.116.241]