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How to save a Canvas with canvas to blob without black background?
I am trying to save a chart from charts.js but its save with a black background and don´t know how to change that background to transparent or white.
I am using Canvas to blob and FileSaver
This is my script
$("#download").click(function() {
var canvas = document.getElementById("canvas");
canvas.toBlob(function(blob) {
saveAs(blob, "grafica.png");
});
});
javascript canvas
asked Jan 2 at 22:37
LuisCasLuisCas
54
add a comment |
I am trying to save a chart from charts.js but its save with a black background and don´t know how to change that background to transparent or white.
I am using Canvas to blob and FileSaver
This is my script
$("#download").click(function() {
var canvas = document.getElementById("canvas");
canvas.toBlob(function(blob) {
saveAs(blob, "grafica.png");
});
});
javascript canvas
asked Jan 2 at 22:37
LuisCasLuisCas
54
add a comment |
I am trying to save a chart from charts.js but its save with a black background and don´t know how to change that background to transparent or white.
I am using Canvas to blob and FileSaver
This is my script
$("#download").click(function() {
var canvas = document.getElementById("canvas");
canvas.toBlob(function(blob) {
saveAs(blob, "grafica.png");
});
});
javascript canvas
asked Jan 2 at 22:37
LuisCasLuisCas
54
I am trying to save a chart from charts.js but its save with a black background and don´t know how to change that background to transparent or white.
I am using Canvas to blob and FileSaver
This is my script
$("#download").click(function() {
var canvas = document.getElementById("canvas");
canvas.toBlob(function(blob) {
saveAs(blob, "grafica.png");
});
});
javascript canvas
javascript canvas
asked Jan 2 at 22:37
LuisCasLuisCas
54
asked Jan 2 at 22:37
LuisCasLuisCas
54
edited Jan 2 at 23:02
LuisCas
asked Jan 2 at 22:37
LuisCasLuisCas
54
asked Jan 2 at 22:37
LuisCasLuisCas
54
asked Jan 2 at 22:37
LuisCasLuisCas
54
54
add a comment |
add a comment |
2 Answers
2
active
oldest
votes
I'm not familiar with the library but have you tried actually giving it a white background? Something like the following? It might be using black a default when no color is encountered at a particular pixel.
$("#download").click(function() {
var canvas = document.getElementById("canvas"),
ctx = canvas.getContext("2d");
ctx.fillStyle = "#ffffff";
ctx.fillRect(0, 0, canvas.width, canvas.height);
canvas.toBlob(function(blob) {
saveAs(blob, "grafica.png");
});
});
answered Jan 2 at 23:06
oooyayaoooyaya
959926
okay it paints everything with white but now the chart doesn´t show haha
– LuisCas
Jan 2 at 23:12
add a comment |
i just draw a white backgroung before draw the chart on the script and solve the black background problem :)
var backgroundColor = 'white';
Chart.plugins.register({
beforeDraw: function(c) {
var ctx = c.chart.ctx;
ctx.fillStyle = backgroundColor;
ctx.fillRect(0, 0, c.chart.width, c.chart.height);
}
});
answered Jan 2 at 23:39
LuisCasLuisCas
54
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
I'm not familiar with the library but have you tried actually giving it a white background? Something like the following? It might be using black a default when no color is encountered at a particular pixel.
$("#download").click(function() {
var canvas = document.getElementById("canvas"),
ctx = canvas.getContext("2d");
ctx.fillStyle = "#ffffff";
ctx.fillRect(0, 0, canvas.width, canvas.height);
canvas.toBlob(function(blob) {
saveAs(blob, "grafica.png");
});
});
answered Jan 2 at 23:06
oooyayaoooyaya
959926
okay it paints everything with white but now the chart doesn´t show haha
– LuisCas
Jan 2 at 23:12
add a comment |
I'm not familiar with the library but have you tried actually giving it a white background? Something like the following? It might be using black a default when no color is encountered at a particular pixel.
$("#download").click(function() {
var canvas = document.getElementById("canvas"),
ctx = canvas.getContext("2d");
ctx.fillStyle = "#ffffff";
ctx.fillRect(0, 0, canvas.width, canvas.height);
canvas.toBlob(function(blob) {
saveAs(blob, "grafica.png");
});
});
answered Jan 2 at 23:06
oooyayaoooyaya
959926
okay it paints everything with white but now the chart doesn´t show haha
– LuisCas
Jan 2 at 23:12
add a comment |
I'm not familiar with the library but have you tried actually giving it a white background? Something like the following? It might be using black a default when no color is encountered at a particular pixel.
$("#download").click(function() {
var canvas = document.getElementById("canvas"),
ctx = canvas.getContext("2d");
ctx.fillStyle = "#ffffff";
ctx.fillRect(0, 0, canvas.width, canvas.height);
canvas.toBlob(function(blob) {
saveAs(blob, "grafica.png");
});
});
answered Jan 2 at 23:06
oooyayaoooyaya
959926
I'm not familiar with the library but have you tried actually giving it a white background? Something like the following? It might be using black a default when no color is encountered at a particular pixel.
$("#download").click(function() {
var canvas = document.getElementById("canvas"),
ctx = canvas.getContext("2d");
ctx.fillStyle = "#ffffff";
ctx.fillRect(0, 0, canvas.width, canvas.height);
canvas.toBlob(function(blob) {
saveAs(blob, "grafica.png");
});
});
answered Jan 2 at 23:06
oooyayaoooyaya
959926
answered Jan 2 at 23:06
oooyayaoooyaya
959926
answered Jan 2 at 23:06
oooyayaoooyaya
959926
answered Jan 2 at 23:06
oooyayaoooyaya
959926
959926
okay it paints everything with white but now the chart doesn´t show haha
– LuisCas
Jan 2 at 23:12
add a comment |
okay it paints everything with white but now the chart doesn´t show haha
– LuisCas
Jan 2 at 23:12
okay it paints everything with white but now the chart doesn´t show haha
– LuisCas
Jan 2 at 23:12
okay it paints everything with white but now the chart doesn´t show haha
– LuisCas
Jan 2 at 23:12
add a comment |
i just draw a white backgroung before draw the chart on the script and solve the black background problem :)
var backgroundColor = 'white';
Chart.plugins.register({
beforeDraw: function(c) {
var ctx = c.chart.ctx;
ctx.fillStyle = backgroundColor;
ctx.fillRect(0, 0, c.chart.width, c.chart.height);
}
});
answered Jan 2 at 23:39
LuisCasLuisCas
54
add a comment |
i just draw a white backgroung before draw the chart on the script and solve the black background problem :)
var backgroundColor = 'white';
Chart.plugins.register({
beforeDraw: function(c) {
var ctx = c.chart.ctx;
ctx.fillStyle = backgroundColor;
ctx.fillRect(0, 0, c.chart.width, c.chart.height);
}
});
answered Jan 2 at 23:39
LuisCasLuisCas
54
add a comment |
i just draw a white backgroung before draw the chart on the script and solve the black background problem :)
var backgroundColor = 'white';
Chart.plugins.register({
beforeDraw: function(c) {
var ctx = c.chart.ctx;
ctx.fillStyle = backgroundColor;
ctx.fillRect(0, 0, c.chart.width, c.chart.height);
}
});
answered Jan 2 at 23:39
LuisCasLuisCas
54
i just draw a white backgroung before draw the chart on the script and solve the black background problem :)
var backgroundColor = 'white';
Chart.plugins.register({
beforeDraw: function(c) {
var ctx = c.chart.ctx;
ctx.fillStyle = backgroundColor;
ctx.fillRect(0, 0, c.chart.width, c.chart.height);
}
});
answered Jan 2 at 23:39
LuisCasLuisCas
54
answered Jan 2 at 23:39
LuisCasLuisCas
54
answered Jan 2 at 23:39
LuisCasLuisCas
54
answered Jan 2 at 23:39
LuisCasLuisCas
54
54
add a comment |
add a comment |
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